Why no 32V GM V8's?
Grintloc
bodies, etc)? In general, wouldn't more valves per cylinder provide both more
power and better efficiency? Would this be an expensive setup, and thus be the
reason for them not making an engine like this, or something else? Or am I
just way off in my thinking? Just wondering.
Grintlocamanoliomastermanhestheonewiththemasterplan
Christer Medin
Wasn't the LT5 a 32 valve setup?
Either way, I think price is the main issue here...
C
DJMika
ultra rare, ultra pricy corvette ZR1. But technically, GM has never actually
made a 32 valve set up, The motor in the ZR1 which I believe was tagged as the
LT5, was made for GM by Lotus. who would want to spend the extra money anyway?
The LS1 makes far more HP than the mustang's 4.6 OHC motor, and I don't know
what kind of milage the stang gets, but the camaro's are around 27 on the
highway. I wouldn't complain about that! Not to mention, the camaro finds ways
to outperform it's OHC counterpart with the wicked LS1 and still stay
considerably cheaper. Push rod power!
DJMIKA
Steven Fisher
> aren't some of the caddy northstar engines quad overhead cam?
I hope you mean dual overhead cam. quad overhead cam in a V engine
would be 8 cams.
Thomas Ketelsen
32V engine. Not why no OverHead CAm! There is an aftermarket set of heads out
made to fit a stock 350 block. These heads have 32 Valves actuated by the stock
cam, pushrod set up. In tests by a nationally published drag racing magazine.
These heads made close to 500hp on a stock 350. The increase in horsepower is due
to using smaller valves and lighter parts than trying to use two very large and
heavy valves.
As for why doesn't Chevolet put it on there cars. I'd have to agree with
another readers opinion and say that it is cost that Chevolet is looking at. but
that doesn't mean that you can't turn around and put these heads on your car after
you purchase it.
Thomas
ma...@mec.edu
>Why would GM put 16 valve small blocks in their new muscle cars (Corvette, F
>bodies, etc)? In general, wouldn't more valves per cylinder provide both more
>power and better efficiency? Would this be an expensive setup, and thus be the
>reason for them not making an engine like this, or something else? Or am I
>just way off in my thinking? Just wondering.
aren't some of the caddy northstar engines quad overhead cam?
---------------------------------------------------
= Do not meddle in the affairs of dragons, =
= For you are crunchy, and good with mustard =
= =
= ma...@MEC.Edu =
---------------------------------------------------
M Talley
>aren't some of the caddy northstar engines quad overhead cam?
I believe the engine in the Allante was a 32V. Of course, the motor
in the Vette ZR-1 was a 32 valver. However, I believe I remember that
is was basically discontinued due to the advances made with the 16V
motors. The horsepower gap was narrowing so rapidly as to make the
several thousand dollar additional cost of the admittedly low-volume
ZR-1 motor not worth it.
Generally speaking, most 32V applications would be relatively
low-volume and high cost. If GM went forward with a 32V motor in a
Z-28, for example, it'd probably be a smaller displacement motor (in
the 300 ci range, for example) and would maintain a similar horsepower
rating with a lower torque rating. Torque, however, is the main
fascination with Firebirds/Camaros, etc. (I like torque, personally:)
Malcolm
Chuck Tomlinson
>
>aren't some of the caddy northstar engines quad overhead cam?
Actually, _all_ the Cadillac Northstar engines are 32V V8s, as is
the Aurora's engine. Those 32V engines, like similar displacement
engines from a certain other Big 3 automaker, are externally larger,
less powerful, more expensive, and no more fuel efficient than the
"primitive" pushrod LS1. Pretty easy design choice, IMHO.
--
Chuck Tomlinson
Richard Fay
> Actually, _all_ the Cadillac Northstar engines are 32V V8s, as is
> the Aurora's engine. Those 32V engines, like similar displacement
> engines from a certain other Big 3 automaker, are externally larger,
> less powerful, more expensive, and no more fuel efficient than the
> "primitive" pushrod LS1.
The Northstar is 1.1L smaller than the LS-1 yet produces 305hp.
Must be doing something right.
Richard
Chuck Tomlinson
>
>The Northstar is 1.1L smaller than the LS-1 yet produces 305hp.
>Must be doing something right.
Really? How does the owner of a Northstar benefit from the smaller
displacement? Cheaper parts? Nope. Better fuel economy? Highly
unlikely. Lower maintenance costs? Nope. Better performance?
Sorry.
How does the designer of a Northstar chassis benefit from the
smaller displacement? Is it externally smaller than the LS1? Less
expensive to build? Lighter in weight? No, no, and no.
So tell me: what *significant* thing is the Northstar doing right,
in relation to the LS1? And who is receiving the benefit from it?
--
Chuck Tomlinson
David Lyons
>
> GM has had a setup like the one you have described. You can find it in the
> ultra rare, ultra pricy corvette ZR1. But technically, GM has never actually
> made a 32 valve set up, The motor in the ZR1 which I believe was tagged as the
> LT5, was made for GM by Lotus. who would want to spend the extra money anyway?
> The LS1 makes far more HP than the mustang's 4.6 OHC motor, and I don't know
> what kind of milage the stang gets, but the camaro's are around 27 on the
> highway. I wouldn't complain about that! Not to mention, the camaro finds ways
> to outperform it's OHC counterpart with the wicked LS1 and still stay
> considerably cheaper. Push rod power!
> DJMIKA
Let's see, the Ford 4.6 DOHC is rated at 305 hp, just like the LS1 in
the F-bodies. Now there that issue of those claims that the LS1 is
underrated while the Ford is overrated. But that's all they are -
claims. For '99, the 4.6 DOHC is getting 20 or 30 more horsepower.
So, if the claims of under- and overratings are true, then they'll be
pretty even in '99. Either way, I wouldn't say the LS1 makes "far
more" HP than the Mustang's 4.6.
Now, who says there is no 32 valve GM V8s? Isn't the Northstar a 32
valve GM V8?
Dave
rmoburg
Marketing.... 32V logos sell quite well.
But, I also think you have hit on a real problem with GM. Cadillac
wouldn't let Olds have the real Northstar at 4.6 they had to cripple
it.
Michael Ereon
From: grin...@aol.com (Grintloc) Why no 32V GM V8's?
(Corvette, F bodies, etc)? In general, wouldn't more valves per cylinder
provide both more power and better efficiency? Would this be an
expensive setup, and thus be the reason for them not making an engine
like this, or something else? Or am I just way off in my thinking? Just
wondering.
**Latest issue of Hot Rod says GM will used SOHC and DOHC in all of its
engines in the 20001 model year.
See ya!
Mike
*****
The dude formerly known as BANDIT80 and MontePooh!
****
1986 Pontiac Grand Prix LE LG-4 5.0
rmoburg
wrote:
>Chuck Tomlinson wrote:
>
>> Actually, _all_ the Cadillac Northstar engines are 32V V8s, as is
>> the Aurora's engine. Those 32V engines, like similar displacement
>> engines from a certain other Big 3 automaker, are externally larger,
>> less powerful, more expensive, and no more fuel efficient than the
>> "primitive" pushrod LS1.
>
>The Northstar is 1.1L smaller than the LS-1 yet produces 305hp.
>Must be doing something right.
>
>Richard
In displacement yes.. But certainly not is physical size, or I believe
weight. Who cares about bore size if the efficiency is there?
Brandon Sommerville
>So tell me: what *significant* thing is the Northstar doing right,
>in relation to the LS1?
Using technology to replace displacement thus allowing better
marketing.
>And who is receiving the benefit from it?
GM of course.
--
Brandon
Never underestimate the power of
stupid people in large groups.
PingP...@juno.com
Steven Fisher <s...@somewhere.srf.com> wrote in article
<35EB6030...@somewhere.srf.com>...
> ma...@MEC.Edu wrote:
> > aren't some of the caddy northstar engines quad overhead cam?
>
> I hope you mean dual overhead cam. quad overhead cam in a V engine
> would be 8 cams.
>
Not all 'overhead cam' engines have a minimum of two camshafts. Ever heard
of a SOHC versus DOHC engines where a single cam takes care of intake and
exhaust valves?
Dean E. Lopez
<4196-35E...@newsd-152.iap.bryant.webtv.net>...
> **Latest issue of Hot Rod says GM will used SOHC and DOHC in all of its
> engines in the 20001 model year.
^^^^^
>
>
> See ya!
See ya?! You plan on living that long? ;)
--
Dean E. Lopez lop...@hou.valmet.com
Systems Analyst, RTU Firmware Engineering
Valmet Automation Houston, Texas USA
'98 WHITE TA M6 TT 16"CHROME K&N BORLA
13.42 @ 105.04
TOSadvisor
Brandon Sommerville wrote in message
<35ef2368....@news.powersurfr.com>...
>Chuck Tomlinson wrote:
>
>>So tell me: what *significant* thing is the Northstar doing right,
>>in relation to the LS1?
>
>Using technology to replace displacement thus allowing better
>marketing.
>
How exactly does a smaller displacement allow for better marketing if there
is no significant economy with the smaller displacement????
Mark A. Cochran
In article <4196-35E...@newsd-152.iap.bryant.webtv.net>,
Michael Ereon <GrandP...@webtv.net> wrote:
>**Latest issue of Hot Rod says GM will used SOHC and DOHC in all of its
>engines in the 20001 model year.
>
Personally, I'd expect the engines in the 20001 model year to be
nuclear or somesuch.
[This account protected by Spamgard(tm) - Mail without 'banana' in the
Subject: header will be bounced unseen.]
PGP and .sig file follows.
A fool must now and then be right by chance.
-----BEGIN PGP SIGNATURE-----
Version: 2.6.i
iQCVAgUBNexLEto7GDsbn4ZNAQGmGQP+LI6Nabmwz74mW12S0OBRJaaOP4xesRUC
NJJqUfXoKRns4oxalbaJsMNHi0wk1QMPRWbrlifAN6vEFln+0z6gsQPprIKeCfMN
kdAAYRSl5IyVzMF9Ifqd4RXSCi4gF3f3KDF4TIkSQWkN8ZOZmWwMWxueCyUt1/pi
ySnBWurx1H8=
=Iqn2
-----END PGP SIGNATURE-----
Michael J. Stepanek
>of a SOHC versus DOHC engines where a single cam takes care of intake and
>exhaust valves?
I'm not sure, but I think SOHC engines actually have 2 cams, and DOHC engines
actually have 4 cams. I'm not sure how the technology works and where the
nomenclature comes from. I should probably find a good web page for it.
Anybody know of one?
Michael J. Stepanek
>engines in the 20001 model year.
They can promise whatever they want for 2001 (I think that's what you
meant... hehehe)... first we have to make sure the Camarobirds live that long.
rmoburg
AH! Now you sound like a GM engineer!
jason
people thought about them. What engine was the best choice for power?
How reliable are cars that old? I know it's going to be low but what
kind of gas mileage do they get? Thanks for the help.
Jason
Homer Simpson
>fa...@antispamozemail.com.au wrote:
>>
>>The Northstar is 1.1L smaller than the LS-1 yet produces 305hp.
>>Must be doing something right.
>
>displacement? Cheaper parts? Nope. Better fuel economy? Highly
>unlikely. Lower maintenance costs? Nope. Better performance?
>Sorry.
>
>How does the designer of a Northstar chassis benefit from the
>smaller displacement? Is it externally smaller than the LS1? Less
>expensive to build? Lighter in weight? No, no, and no.
>
>--
>Chuck Tomlinson
>
The only notable thing I can think of where the Northstar motor has an
advantage comes from computer management. The "Northstar System" provides
for alternating banks of four cylinders to shut down to prevent overheating
in the event of a cooling system failure. This run mode is accompanied by a
greatly enrichened fuel mixture (also to aid in cooling). Significantly
less horsepower, but you're not stranded.
Brian Grimal
Black 98 Formula M6, TT, Chrome, !MAF
60ft.: 2.123 1/8 Mile: 8....@81.49MPH 1/4 Mile: 13....@103.31MPH
The Ennui Society
Michael J. Stepanek wrote:
No, SOHC means Single OverHead Camshaft, meaning one camshaft operating BOTH
intake and exhaust valves. DOHC uses one camshaft to operate the intake valves
and other camshaft to focus on exhaust valves as found on Audi and Volkswagen
turbo 1,8-litre four-cylinder motors as well as Cadillac Northstar and Ford Romeo
V8 (in Lincoln Continential, Ford Mustang Cobra, etc.)
If the V8 motor have one camshaft operating one bank of cylinders, it is
considered SOHC whilst the same motor with two camshafts per bank is considered
DOHC. Confusing, perhaps?
The technology in motors advanced so much that the performance gap between OHV
(OverHead Valve with camshaft right above the crankshaft operating the valves in
both bank of cylinders with pushrods) and OHC as well as SOHC and DOHC is so
narrow that the engineers can choose the optimal configuration. Mercedes-Benz
built the OHV motor for Indy and did extremely well to the surprise of motoring
world.
Regards,
Oliver
Michael Ereon
From: mste...@vt.edu (Michael J. Stepanek) Re: Why no 32V GM V8's?
**Oops, did I say 20001? : )
Michael Ereon
From: fsta...@aol.com (FStanbach) Re: Why no 32V GM V8's?
>>**Latest issue of Hot Rod says GM will used >>SOHC and DOHC in all of
its engines in the >>20001 model year.
>>Mike
>Why would they do that? The 3800 is the most >reliable engine gm has.
**Isn't the Series II an overhead cam engine?
Terance Coll
> GM has a world-class engine in the N*, and they also have a very
> nice engine in the LS1, but they are two completely different engines.
> The LS1 produces low end grunt that the N* is envious of, but the N* revs
> like a Ferrari. You can't do that with the LS1.
>
I would have to disagree totally. The LS1 lacks low end grunt but rev's very
freely...at least compared to my LT1. Bounce an LS1 off that revlimiter at
6200 a few times and you wish it were alot higher :)
--
Terance Coll
ICQ#1795288,(512)965-1197
http://austin.f-body.org/members/coll/index.html
96 Z28 Silver,T-Tops,M6,NX kit,S-Trim come'n soon! :)
Steven Fisher
> I'm not sure, but I think SOHC engines actually have 2 cams, and DOHC engines
> actually have 4 cams. I'm not sure how the technology works and where the
> nomenclature comes from. I should probably find a good web page for it.
> Anybody know of one?
SOHC has one cam per bank, DOHC two per bank. Thus, dual and single.
FStanbach
Chuck Tomlinson
>
>The only notable thing I can think of where the Northstar motor has an
>advantage comes from computer management. The "Northstar System" provides
>for alternating banks of four cylinders to shut down to prevent overheating
>in the event of a cooling system failure. This run mode is accompanied by a
>greatly enrichened fuel mixture (also to aid in cooling). Significantly
>less horsepower, but you're not stranded.
Ahhh, another nod to the marketing geniuses at Cadillac. As far as
I can tell, that feature is nothing but software, and can be applied
to any sufficiently powerful engine that can run fairly smoothly on
half its cylinders. IOW, they could do exactly the same with the
LS1, but Cadillac needs a(nother) gimmick to sell Northstars.
And for heaven's sake, does anyone really care that a new luxury car
can run with a fully-failed cooling system? If I'm buying a $50k
luxury car, that cooling system better work *perfectly* for years.
Don't get me wrong: the "Northstar system" is a pretty neat bag o'
tricks, with a sweet engine in the middle of it. But I don't see
that engine doing anything that an LS1 couldn't be made to do (at
least as well). Oh, except sell cars to spec-shoppers, that is...
--
Chuck Tomlinson
Brandon Sommerville
>
>Brandon Sommerville wrote in message
><35ef2368....@news.powersurfr.com>...
>>Chuck Tomlinson wrote:
>>
>>>So tell me: what *significant* thing is the Northstar doing right,
>>>in relation to the LS1?
>>
>>Using technology to replace displacement thus allowing better
>>marketing.
>>
>
>
>How exactly does a smaller displacement allow for better marketing if there
>is no significant economy with the smaller displacement????
>
DOHC, four cam, 32V. All the right buzzwords to entice the import
crowd. Many import buyers feel their cars are superior due to more
sophisticated technology without realizing what that technology does,
so they throw techspeak at them. The Northstar engine does that,
something that the barbaric pushrod LS1 can't do.
Let's just ignore the fact that the LS1 is superior in power output,
fuel economy, cost and packaging size.
Graydon D. Stuckey
> >So tell me: what *significant* thing is the Northstar doing right,
> >in relation to the LS1? And who is receiving the benefit from it?
>
> Marketing.... 32V logos sell quite well.
That's a rather nearsighted view of the Northstar engine.
> But, I also think you have hit on a real problem with GM. Cadillac
> wouldn't let Olds have the real Northstar at 4.6 they had to cripple
> it.
Olds didn't need the 4.6 N* to supply adequate hp in the Aurora. Its
only 600 cc - hardly enough to really sneeze at. There are 4.0 litre N*
engines making over 350hp in emissions legal trim. In race trim, they
make over 750hp. I don't think its really "crippled."
GM has a world-class engine in the N*, and they also have a very
nice engine in the LS1, but they are two completely different engines.
The LS1 produces low end grunt that the N* is envious of, but the N* revs
like a Ferrari. You can't do that with the LS1.
Later,
Graydon D. Stuckey
Quick305
>the F-bodies. Now there that issue of those claims that the LS1 is
>underrated while the Ford is overrated. But that's all they are -
>claims. For '99, the 4.6 DOHC is getting 20 or 30 more horsepower.
>So, if the claims of under- and overratings are true, then they'll be
>pretty even in '99. Either way, I wouldn't say the LS1 makes "far
>more" HP than the Mustang's 4.6.
>
>Now, who says there is no 32 valve GM V8s? Isn't the Northstar a 32
>valve GM V8?
>
>Dave
dave I have seen it at the track, some ls1 cars are very very fast while others
aren't any better than the lt1. I have seen ls1 cars bone stock capable of mid
to low 13's at sea level and i have seen a couple that could not get out of the
14's any where. and i have seen a 97 vette running 15's. chevy is not being
really consistant with the motor some are nasty fast and some are just ok. now
the ones that are nasty are way more powerful than the 4.6 and the ones that
arent are just about even with he cobras. the cobra is good car, one ford did
right. but the f-bodys are still on top.
Chuck Tomlinson
>
>GM has a world-class engine in the N*, and they also have a very
>nice engine in the LS1, but they are two completely different engines.
>The LS1 produces low end grunt that the N* is envious of, but the N* revs
>like a Ferrari. You can't do that with the LS1.
I have to wonder if you've actually driven a car with an LS1. It's
actually a fairly peaky engine. IMHO, the LS1's power distribution
feels much more like the 300 hp Northstar than the 275 hp Northstar.
By the numbers, the peakier 300 hp Northstar may have a slightly
higher redline than the LS1, but the LS1 has the same peak torque
rpm (4400), and its peak power rpm is only 400 rpm lower than the
300 hp Northstar's (5600 vs 6000). Sorry, but I don't see a major
difference in power delivery between the LS1 and the Northstar.
Also: the Northstar, like *almost all* similar wonder engines, has
remained essentially unchanged in performance since Job One (for
about five years, in this case). The LS1, as powerful as it is now,
is just the beginning of the line for the Gen III small block.
--
Chuck Tomlinson
Richard Fay
>
> Let's just ignore the fact that the LS1 is superior in power output,
> fuel economy, cost and packaging size.
> --
Worse fuel economy. Where is your proof? The Northstar is fitted to
heavy Cadillacs and the LS-1 is under the bonnets of so-called
lightweight sportscars.
Richard
Chuck Tomlinson
>Brandon Sommerville wrote:
>
>> Let's just ignore the fact that the LS1 is superior in power output,
>> fuel economy, cost and packaging size.
>
>heavy Cadillacs and the LS-1 is under the bonnets of so-called
>lightweight sportscars.
No proof, I have some clues. The 1996 Cadillac Fleetwood was
powered by a 260 hp LT1 pushrod engine. This 4400 lb monster had
the same government fuel economy rating (17 city/ 26 hwy) as the
3900 lb Cadillac Seville SLS with a 275 hp Northstar.
The LS1 is at least as fuel-efficient as the LT1 (the 305 hp LS1
F-body has equal or better fuel economy than the 285 hp LT1).
IOW, test data suggests (to me) that the LS1 and Northstar are very
close in fuel consumption, though I can't say for sure which one has
the edge (and neither can any Northstar/32V aficionados).
--
Chuck Tomlinson
rmoburg
<gra...@apollo.kettering.edu> wrote:
>On Tue, 1 Sep 1998, rmoburg wrote:
>
>> >So tell me: what *significant* thing is the Northstar doing right,
>> >in relation to the LS1? And who is receiving the benefit from it?
>>
>> Marketing.... 32V logos sell quite well.
>
>That's a rather nearsighted view of the Northstar engine.
And also was a sarcastic remark. The Northstar is a very fine engine
as is the Ford 4.6. But not the end of OHV engines.
>> But, I also think you have hit on a real problem with GM. Cadillac
>> wouldn't let Olds have the real Northstar at 4.6 they had to cripple
>> it.
>
>Olds didn't need the 4.6 N* to supply adequate hp in the Aurora. Its
>only 600 cc - hardly enough to really sneeze at. There are 4.0 litre N*
>engines making over 350hp in emissions legal trim. In race trim, they
>make over 750hp. I don't think its really "crippled."
But hardly enough HP for the Aurora. It's been one of the main
criticisms of the car, along with it's sloppy handling. And why do it
in the first place? GM gained nothing by downsizing the Olds engine
other than, IMO, protecting Cadillac.
>GM has a world-class engine in the N*, and they also have a very
>nice engine in the LS1, but they are two completely different engines.
>The LS1 produces low end grunt that the N* is envious of, but the N* revs
>like a Ferrari. You can't do that with the LS1.
>
>
I'm not sure you have experienced the LS1. Not an enormous amount of
low end grunt. More like a fairly balanced engine. You must be
thinking of the LT-1.
Dean E. Lopez
<199809020451...@ladder03.news.aol.com>...
>
> dave I have seen it at the track, some ls1 cars are very very fast while
others
> aren't any better than the lt1. I have seen ls1 cars bone stock capable
of mid
> to low 13's at sea level and i have seen a couple that could not get out
of the
> 14's any where. and i have seen a 97 vette running 15's. chevy is not
being
> really consistant with the motor some are nasty fast and some are just
ok. now
> the ones that are nasty are way more powerful than the 4.6 and the ones
that
> arent are just about even with he cobras. the cobra is good car, one ford
did
> right. but the f-bodys are still on top.
>
The problem as I see it with LS1-powered cars times being all over the
place is the learning curve on how to launch these beasts on street
radials. It has very little to do with the engine itself, other than the
fact that it does produce more power than most new LS1 owners are used to.
The LS1 owners who've had their car to the track a more than a few times
are consistently seeing low to mid 13 second times. If I see an LS1 driver
running 14's, I'll put sure money down that they're just learning how to
race it!
danah...@my-dejanews.com
toml...@ix.netcom.com (Chuck Tomlinson) wrote:
> Actually, _all_ the Cadillac Northstar engines are 32V V8s, as is
> the Aurora's engine. Those 32V engines, like similar displacement
> engines from a certain other Big 3 automaker, are externally larger,
> less powerful, more expensive, and no more fuel efficient than the
> "primitive" pushrod LS1.
The Northstar engine design is also several years older than the LS1.
Much has been learned about engine design over those years. When the
DOHC engine was first released, I believe it had similar power to the
pushrod Corvette engine of the same year.
Also, let's not forget that the DOHC engine is going into a luxury
car, not a sports car. Therefore, it seems improbable to me that the
Caddy engine would be tuned for the same level of performance as the
Corvette engine.
If you want to do a close apples-to-apples comparison, how about we
compare the LS1 against the 405hp LT5 engine.
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum
Chuck Tomlinson
> toml...@ix.netcom.com (Chuck Tomlinson) wrote:
>
>> Those 32V engines, like similar displacement
>> engines from a certain other Big 3 automaker, are externally larger,
>> less powerful, more expensive, and no more fuel efficient than the
>> "primitive" pushrod LS1.
>
>The Northstar engine design is also several years older than the LS1.
>Much has been learned about engine design over those years. When the
>DOHC engine was first released, I believe it had similar power to the
>pushrod Corvette engine of the same year.
Yes, it did. That old pushrod design went on to produce 10% more
power, while the Northstar remains unchanged to this day. The
pushrod engine was still smaller than the 32V, although the iron
block made it heavier than the all-aluminum Northstar. As I wrote
in another post, the old LT1 and the Northstar were similarly
fuel-efficient. Needless to say, the LT1 was much less expensive.
>Also, let's not forget that the DOHC engine is going into a luxury
>car, not a sports car. Therefore, it seems improbable to me that the
>Caddy engine would be tuned for the same level of performance as the
>Corvette engine.
The Vette engine is very smooth, mild, and quiet. If you've driven
a Seville STS, you'll know why there are two versions of the
Northstar. The 300 hp version is noticeably peakier than the 275 hp
version, and it's not exactly silent. IOW, the LS1 and the 300 hp
Northstar are more similar in tuning than one might guess.
>If you want to do a close apples-to-apples comparison, how about we
>compare the LS1 against the 405hp LT5 engine.
Since the LT5 is the size and weight of an all-aluminum big-block
Chevy (BBC), why not compare it to one of those? Any garden-variety
high-performance BBC can make 450+ hp with a glass-smooth idle, for
a fraction of the LT5's cost.
For that matter, a compact iron-block pushrod SBC could *easily*
make that 405 hp with the same hand-porting that the 405 hp LT5
received, plus a simple increase in stroke. Nothing more. And an
iron-block SBC still weighs *less* than the all-aluminum LT5.
For a market without artificial constraints on engine displacement
(like the North American auto market, for example) the story is
simple: for a given external size, weight, cost, power, and fuel
consumption, DOHC V8s have NO useful performance advantages over
modern pushrod V8s. NONE.
--
Chuck Tomlinson
Brandon Sommerville
>Brandon Sommerville wrote:
>
>>
>> Let's just ignore the fact that the LS1 is superior in power output,
>> fuel economy, cost and packaging size.
>> --
>
>Worse fuel economy. Where is your proof? The Northstar is fitted to
>heavy Cadillacs and the LS-1 is under the bonnets of so-called
>lightweight sportscars.
Okay, I'll retract the fuel economy bit, but they are very close. But
I noticed you didn't attack anything else that I mentioned...
FStanbach
>
>See ya!
>Mike
>*****
>The dude formerly known as BANDIT80 and MontePooh!
>****
>1986 Pontiac Grand Prix LE LG-4 5.0
Nope
Josh Turner
>
snip
> Also: the Northstar, like *almost all* similar wonder engines, has
> remained essentially unchanged in performance since Job One (for
> about five years, in this case). The LS1, as powerful as it is now,
> is just the beginning of the line for the Gen III small block.
Almost all? Which "similar wonder engines" are you referring to? Other
4.xL DOHC V8s? I don't have numbers handy, but of the 4.xs I can think
of right off hand, many have had an increase in power since their
introduction. E.g., BMW (displacement increased, power up), Lexus (VVTi
added, power increased), Ford (Cobra's enigne up 20 hp this year through
various tweaks), Jaguar (addition of supercharger ups power to 370).
Infiniti's power decreased, but this was because of a change in
marketing focus, rather than anything about the engine itself. Which
other engines were you thinking of?
I appreciate the point that you are making--pushrod engines are not
inherently flawed next to xOHCs. However, I think that you are carrying
it a bit too far. While Cadillac hasn't made any significant performance
enhancements to the Northstar, I don't think that this is an indication
that they are bumping up against the ceiling of that engine's potential.
Instead, it may be a recognition that 300 hp is, as RR used to say,
"adequate" for the applications that they are using it in--indeed, the
Seville still has one of the highest hp engines in its class, even
without any performance improvements. Moreover, since Cadillac uses the
Northstar exclusively in FWD applications, there may be some hesitation
to go beyond the power that the engine already develops. The Seville is
the highest hp FWD car available, is it not?
Josh Turner
>
>
> For a market without artificial constraints on engine displacement
> (like the North American auto market, for example) the story is
> simple: for a given external size, weight, cost, power, and fuel
> consumption, DOHC V8s have NO useful performance advantages over
> modern pushrod V8s. NONE.
I will admit that I don't understand variable valve timing technology as
well as I could, but it seems to me that applying VVT to a pushrod
engine would be problematic--certainly I have not seen a production
application of this technolgy to an OHV engine. If this is true, then
thedesire to use VVT, with its attendant performance and efficiency
gains, would provide a reason to go with a DOHC design.
Steve L Perkins
cost a fortune to build and warranty, the necessary cam belts to run them
would require changing at 60,000 miles and American pony car buyers will
not spend $1,500 on preventive maintenance. If they used timing chains it
would be very noisy. The LT1 has a 100,000 mile tune up schedule, and it can
blow the doors off any overhead cam V8 on the planet In the same weight car.
and they make them for a wholesale price of $753 long block.!!!
Grintloc wrote in message
<199808312020...@ladder03.news.aol.com>...
>Why would GM put 16 valve small blocks in their new muscle cars (Corvette,
F
>bodies, etc)? In general, wouldn't more valves per cylinder provide both
more
>power and better efficiency? Would this be an expensive setup, and thus be
the
>reason for them not making an engine like this, or something else? Or am I
>just way off in my thinking? Just wondering.
>
>
>Grintlocamanoliomastermanhestheonewiththemasterplan
Chuck Tomlinson
>
>Almost all? Which "similar wonder engines" are you referring to? Other
>4.xL DOHC V8s? I don't have numbers handy, but of the 4.xs I can think
>of right off hand, many have had an increase in power since their
>introduction. E.g., BMW (displacement increased, power up), Lexus (VVTi
>added, power increased), Ford (Cobra's enigne up 20 hp this year through
>various tweaks), Jaguar (addition of supercharger ups power to 370).
I was thinking of powerful DOHC engines that increased their output
by means of evolutionary tuning, not displacement increases or power
adders (which will increase _any_ engine's output). The '99 Ford
Cobra V8 is the only one of those multi-cammed wonders that gained
power without (AFAIK) adding more cubes or more components.
And even the Ford is only now reaching the performance level where
the (smaller/lighter/cheaper) LS1 was born! What a stunning
achievement...
Other sports engines like the NSX's V6 and the Ferrari V8 go for
years without added performance, except via increased displacement.
Why that is, I don't know.
>I appreciate the point that you are making--pushrod engines are not
>inherently flawed next to xOHCs. However, I think that you are carrying
>it a bit too far.
Who me? Nahh... :-)
>While Cadillac hasn't made any significant performance
>enhancements to the Northstar, I don't think that this is an indication
>that they are bumping up against the ceiling of that engine's potential.
>Instead, it may be a recognition that 300 hp is, as RR used to say,
>"adequate" for the applications that they are using it in--
That's a good point. But I wasn't indicating that the Northstar was
already maxed out. I was just observing that similar engines don't
(not can't) seem to evolve performance-wise in the same way that the
pushrod V8s do: by evolving into increasingly powerful versions
without adding even more cost, cubes, or components.
What sent me down that path is how easily an engine like the LS1 can
be dismissed by the multi-cam groupies who apparently can't see that
the cammers bring NOTHING useful to the party except... prestige?
And that's fine: if people want to pay extra money for prestige, I
don't care. But when they claim superiority on the basis of
*performance*, well, I'm afraid I must disagree :-)
>Moreover, since Cadillac uses the
>Northstar exclusively in FWD applications, there may be some hesitation
>to go beyond the power that the engine already develops. The Seville is
>the highest hp FWD car available, is it not?
That is also true. I just find it a bit amusing that the Northstar
Cadillacs could achieve the same performance in a more compact, less
expensive package if GM were to toss the Northstar in favor of
detuned LS1s (yikes!). Of course, the flawed market perception of
inherent multi-cam superiority makes that impossible. Whatever...
--
Chuck Tomlinson
Eric
The 3.5 DOHC I believe is replacing it.
I know its a DOHC 24V setup, and I
think its 3.5 liters.
The new Intrique GLS gets it right now, and
it will be worked into the rest of GM's lines
through next year as the base V6. I'd expect
to see a small motor soon too, to replace the
3.1/3.4 setups.
--
-- Eric 98 Black Z28 M6
13...@107.1mph 2.075 60'
Flowmaster, K&N, B&M Ripper,
!TB, !CAGS, Redline Fluids
Lorena Bobbit EGR Mod
FStanbach wrote in message
<199809020245...@ladder01.news.aol.com>...
Chuck Tomlinson
>
>I will admit that I don't understand variable valve timing technology as
>well as I could, but it seems to me that applying VVT to a pushrod
>engine would be problematic--certainly I have not seen a production
>application of this technolgy to an OHV engine. If this is true, then
>thedesire to use VVT, with its attendant performance and efficiency
>gains, would provide a reason to go with a DOHC design.
I agree that VVT is better suited for a DOHC engine, at least in its
most common form (variable cam gear phasing). In a DOHC engine, you
can change the intake and exhaust cam phasing independently.
In a pushrod engine, controlling cam phasing will advance or retard
the intake and exhaust events equally. That's not as flexible as
the DOHC's independent control, but it's still a useful tuning aid.
Selecting cam phasing is a normal part of any pushrod engine build
(as the a.a.c.f. folks know). Advancing the cam (both intake and
exhaust) improves midrange torque at the expense of top end torque,
and retarding the cam does the opposite.
There is no fundamental reason why that phasing cannot be performed
in real time in a pushrod engine, using *exactly* the same phasing
design as a chain-driven DOHC VVT. The phasing device does not
"know" anything about the rest of the engine. Chain, sprocket, oil
supply: that's all it knows, and those areas are the same in pushrod
and OHC engines (the pushrod parts might be a little beefier, tho').
But VVT adds cost and complexity to an engine design. Current
pushrod engines have competitive power and efficiency without it.
It's quite possible, though, that VVT might appear on future pushrod
engines. It's not a big design deal.
--
Chuck Tomlinson
danah...@yahoo.com
toml...@ix.netcom.com (Chuck Tomlinson) wrote:
> No proof, I have some clues. The 1996 Cadillac Fleetwood was
> powered by a 260 hp LT1 pushrod engine. This 4400 lb monster had
> the same government fuel economy rating (17 city/ 26 hwy) as the
> 3900 lb Cadillac Seville SLS with a 275 hp Northstar.
BTW, the '98 STS with the 300hp Northstar has the same mileage rating,
weighs in almost the same as the Fleetwood at 4,335lbs, and AFAIK is
faster than the pushrod Fleetwood. Would you still suggest that the
DOHC is not more fuel efficient than the pushrod engine?
Quick305
>place is the learning curve on how to launch these beasts on street
>radials. It has very little to do with the engine itself, other than the
>fact that it does produce more power than most new LS1 owners are used to.
>The LS1 owners who've had their car to the track a more than a few times
>are consistently seeing low to mid 13 second times. If I see an LS1 driver
>running 14's, I'll put sure money down that they're just learning how to
>race it!
>
>--
>Dean E. Lopez lop...@hou.valmet.com
>Systems Analyst, RTU Firmware Engineering
>Valmet Automation Houston, Texas USA
>'98 WHITE TA M6 TT 16"CHROME K&N BORLA
>13.42 @ 105.04
naw man there is a guy with a 98 WS6 auto out here turning 14.7's@ 96-97 really
consistantly and pulling 2.1 60' times he is doing it right the car just does
not have the power. and there is another guy with a bone stock 6 speed TA
turning 14.0's up here and his traps are at 102-103 mph. the autos seem to be
hurt pretty badly i think it is because of the torque curve of the ls1. and
another guy with a 98 ss can only get 14.5 out of his 6 speed. those cars are
weird some are alot faster than others. production variences are too wide. well
i guess it is the same with the 5.0 stangs some can hit low 15's bone stock and
some people say they can hit mid to low 14's with them bone stock. but for some
reason the lt1 cars only vary a couple tenths at the track. i dunno what the
deal is.
w...@gate.net
ma...@MEC.Edu wrote:
> aren't some of the caddy northstar engines quad overhead cam?
>
> ---------------------------------------------------
> = Do not meddle in the affairs of dragons, =
> = For you are crunchy, and good with mustard =
> = =
> = ma...@MEC.Edu =
> ---------------------------------------------------
ALL of the Caddy Northstar engines are DOHC!
Bill
w...@gate.net
Chuck Tomlinson
>
>BTW, the '98 STS with the 300hp Northstar has the same mileage rating,
>weighs in almost the same as the Fleetwood at 4,335lbs, and AFAIK is
>faster than the pushrod Fleetwood. Would you still suggest that the
>DOHC is not more fuel efficient than the pushrod engine?
According to Edmund's (same place I got the Fleetwood's weight), the
'98 STS weighs 4,000 lbs, 10% less than the Fleetwood. Even the
heavier '98 DeVille is listed at 4,052 lbs vs. 4,447 lbs for the
Fleetwood. Also, the Fleetwood was equipped with the "old" LT1, not
the newer (and possibly more fuel-efficient) LS1.
So... yes, I would still suggest that there is insufficient evidence
that the Northstar is more fuel efficient than the LT1, let alone
the LS1. The simple fact is that we _cannot_ say for sure, unless
someone posts part-throttle BSFC curves for those engines. I'm not
holding my breath...
--
Chuck Tomlinson
Jeff Reid
I thought that this thread was about 32V V8's not necessarily
OHC 32V V8's, doesn't Dominion make a 32V head for the LT1?
Because of the better partial opening flow with a 4 valve
per cylinder setup, it seems that the Dominion heads would
result in a significant increase in both torque and power.
> What sent me down that path is how easily an engine like the LS1 can
> be dismissed by the multi-cam groupies who apparently can't see that
> the cammers bring NOTHING useful to the party except... prestige?
If the red-line is not much over 6,500 rpm, there's probably
no real advantage of OHC, since a pushrod setup can drive a
2 or 4 valve per cylinder setup (eg the Dominion head), but an easy
way to get power is to increase rpm, and at higher rpms, an
OHC setup is required.
To compare apples with apples, try comparing a Ferrari DOHC 5+liter
V8 with an LS1. If I remember correctly, in spite of the fact
that red-line is around 8,500 rpm, the Ferrari had a better/bigger
torque
curve, not to mention an extra 100 hp or so. Of course, if you compare
horsepower and torque versus cost, the LS1 wins easily. The BMW
V12 used in the McLaren F1 (627hp) easily outperfoms the Viper V10
(450hp stock), even though the Viper engine is much bigger
(8 liters versus 6.1).
I drive a 1997 TA WS6 M6 (5.7 liter, 305 hp, 5800 to 6000rpm redline),
and a 1992 Kawasaki ZX-11 (1.06 liter, 145 hp, 11,500 rpm redline),
both have relatively flat torque curves (the ZX-11's power band
is from about 4,000 to 11,000 rpm, almost 2/3rds of its rpm range).
It's the high rpms that give the Kawasaki its power.
Chuck Tomlinson
>
>I thought that this thread was about 32V V8's not necessarily
>OHC 32V V8's, doesn't Dominion make a 32V head for the LT1?
You're right, I wasn't thinking about the Dominions. It's too bad
they were limited to making a bolt-on part -- IIRC, some of the head
bolts end up in the exhaust ports. Sounds promising, but expensive.
>If the red-line is not much over 6,500 rpm, there's probably
>no real advantage of OHC, since a pushrod setup can drive a
>2 or 4 valve per cylinder setup (eg the Dominion head), but an easy
>way to get power is to increase rpm, and at higher rpms, an
>OHC setup is required.
The redline is secondary IMHO, though some folks (not you) make it
sound like an end in itself. They are usually the DOHC crew who are
desperate to find something that their engines can do "better" than
a primitive pushrod V8.
Anyway, the bottom line is performance. If you can get, say, 400 hp
at 6,500 rpm with a pushrod 16V engine, why spend more money to get
400 hp at 8,000 rpm from an OHC engine with smaller displacement but
has similar weight, external size, and other performance measures?
>To compare apples with apples, try comparing a Ferrari DOHC 5+liter
>V8 with an LS1. If I remember correctly, in spite of the fact
>that red-line is around 8,500 rpm, the Ferrari had a better/bigger
>torque curve, not to mention an extra 100 hp or so.
I've never heard of a 5L Ferrari V8; maybe you mean 3.5L? That
engine has an 8,500 rpm redline, but has only 30 hp more than an
LS1. I'd love to have someone give me that engine (and the car it
comes in), but the price of that 30 hp is hilarious to anyone of
normal financial means.
>Of course, if you compare
>horsepower and torque versus cost, the LS1 wins easily.
Exactly. I don't know how much a 3.5L Ferrari V8 costs, but I'd be
amazed if it cost less than $15,000. Some people can justify
spending an extra ~$10k for 30 hp and 2,500 rpm. I can't.
>The BMW
>V12 used in the McLaren F1 (627hp) easily outperfoms the Viper V10
>(450hp stock), even though the Viper engine is much bigger
>(8 liters versus 6.1).
I just don't think it's sensible to compare mass-produced engines
with cost-is-no-object engines. IMHO, the Mac's V12 could be
matched by any number of pushrod combos, at a fraction of the cost.
--
Chuck Tomlinson
Gary H
wrote:
>Chuck Tomlinson wrote:
>
>> Actually, _all_ the Cadillac Northstar engines are 32V V8s, as is
>> the Aurora's engine. Those 32V engines, like similar displacement
>> engines from a certain other Big 3 automaker, are externally larger,
>> less powerful, more expensive, and no more fuel efficient than the
>> "primitive" pushrod LS1.
>
>The Northstar is 1.1L smaller than the LS-1 yet produces 305hp.
>Must be doing something right.
>
>Richard
Ever see a dyno test of a Northstar Caddie? I saw an Eldo, dynoed
around 230 at the wheels! yucky!
Gary H
Tomlinson) wrote:
>I was thinking of powerful DOHC engines that increased their output
>by means of evolutionary tuning, not displacement increases or power
>adders (which will increase _any_ engine's output). The '99 Ford
>Cobra V8 is the only one of those multi-cammed wonders that gained
>power without (AFAIK) adding more cubes or more components.
What about the Lexus V8s? They have steadily increased in power.
Gary H
>In article <6siv72$l...@dfw-ixnews3.ix.netcom.com>,
> toml...@ix.netcom.com (Chuck Tomlinson) wrote:
>
>> No proof, I have some clues. The 1996 Cadillac Fleetwood was
>> powered by a 260 hp LT1 pushrod engine. This 4400 lb monster had
>> the same government fuel economy rating (17 city/ 26 hwy) as the
>> 3900 lb Cadillac Seville SLS with a 275 hp Northstar.
>
>BTW, the '98 STS with the 300hp Northstar has the same mileage rating,
>weighs in almost the same as the Fleetwood at 4,335lbs, and AFAIK is
>faster than the pushrod Fleetwood. Would you still suggest that the
>DOHC is not more fuel efficient than the pushrod engine?
The '98 STS does not weigh 4335 lbs, where did you read that?
Gary H
Tomlinson) wrote:
>>If you want to do a close apples-to-apples comparison, how about we
>>compare the LS1 against the 405hp LT5 engine.
>
>Since the LT5 is the size and weight of an all-aluminum big-block
>Chevy (BBC), why not compare it to one of those? Any garden-variety
>high-performance BBC can make 450+ hp with a glass-smooth idle, for
>a fraction of the LT5's cost.
>
>For that matter, a compact iron-block pushrod SBC could *easily*
>make that 405 hp with the same hand-porting that the 405 hp LT5
>received, plus a simple increase in stroke. Nothing more. And an
>iron-block SBC still weighs *less* than the all-aluminum LT5.
If we are going to compare, lets compare the LT4 to the LT5. The LT4s
posted very similiair 1/4 mile times!
rick...@my-dejanews.com
gri...@mindless.moc (Brandon Sommerville) wrote:
> TOSadvisor wrote:
>
> >
> >Brandon Sommerville wrote in message
> ><35ef2368....@news.powersurfr.com>...
> >>Chuck Tomlinson wrote:
> >>
> >>>So tell me: what *significant* thing is the Northstar doing right,
> >>>in relation to the LS1?
> >>
> >>marketing.
> >>
> >
> >
> >How exactly does a smaller displacement allow for better marketing if there
> >is no significant economy with the smaller displacement????
> >
> DOHC, four cam, 32V. All the right buzzwords to entice the import
> crowd. Many import buyers feel their cars are superior due to more
> sophisticated technology without realizing what that technology does,
> so they throw techspeak at them. The Northstar engine does that,
> something that the barbaric pushrod LS1 can't do.
>
> Let's just ignore the fact that the LS1 is superior in power output,
> fuel economy, cost and packaging size.
> --
>
> Never underestimate the power of
> stupid people in large groups.
>
Unfortunately, this is a very true statement. What's even worse is that this
supposed 'Cadillac Corvette' isn't even going to get the LS1. The LS1 is
probably the most sophisticated pushrod motor ever built. It's only
disadvtange is that its missing three cams and 16 valves. I guess that's why
I drive a Vette rathen than an Eldorado. Give me proven over time technology
over high-tech gizmos any day.
RickDStik
Sports car discussions and more coming soon at http://www.rickdstik.org/
98 Vette (LS1)Ragtop
danah...@my-dejanews.com
toml...@ix.netcom.com (Chuck Tomlinson) wrote:
> danah...@yahoo.com wrote:
> >
> >BTW, the '98 STS with the 300hp Northstar has the same mileage rating,
> >weighs in almost the same as the Fleetwood at 4,335lbs, and AFAIK is
> >faster than the pushrod Fleetwood. Would you still suggest that the
> >DOHC is not more fuel efficient than the pushrod engine?
>
> '98 STS weighs 4,000 lbs, 10% less than the Fleetwood.
Well that's odd, I found a web site [1] which lists the curb weight
of the '98 STS as 4335lbs (they claim it's the manufacturer's data).
The Cadillac site agrees with your data, so you're correct. Sorry
about that.
The Caddy site [3] also says the '98 STS has a 3.71 rear end (SLS 3.11).
I found another site [2] which says the Fleetwood with the LT1 had a
2.56 rear end (sorry, no model year listed) and goes from 0-60 in 8.5
seconds, significantly slower than the STS (Caddy site claims 6.7).
Assuming I've got my data correct this time, I think you need to compare
the LT1/Northstar in cars which at least have similar gearing.
[1] http://www.auto.com/reviews/qtony62_98seville.htm
[2] http://cartalk.cars.com/Info/Testdrive/Tech-Specs/fleetwood-cadillac.html
[3] http://www.cadillac.com, under "comparison"
Jeff Reid
>>V8 with an LS1. If I remember correctly, in spite of the fact
>>that red-line is around 8,500 rpm, the Ferrari had a better/bigger
>>torque curve, not to mention an extra 100 hp or so.
>
>I've never heard of a 5L Ferrari V8; maybe you mean 3.5L? That
>engine has an 8,500 rpm redline, but has only 30 hp more than an
>LS1. I'd love to have someone give me that engine (and the car it
>comes in), but the price of that 30 hp is hilarious to anyone of
>normal financial means.
I was wrong, (getting my engines mixed up) it's a 5.5 liter
(332 cubic inches) V12 (used in the Maranello 5.5),
485 hp at 7,000 rpm, 421 ft-lb at 5,000 rpm. Unlike the
Mustang and GM's DOHC engines, this one seems to
be making good power and torque for it's displacement.
I was suprised at the amount o torque this engine makes.
Like I said before, the LT1/LS1 win in price per horsepower
war.
Still curious about LT1 performance with a dominion head...
Richard Fay
> Give me proven over time technology
> over high-tech gizmos any day.
>
How long has DOHC been around?? 90 years if I'm not mistaken.
To me that's means it's proven.
What about all the hightech gizmos (computers, EFI) that let the LS-1
produce the power it does. They obviously don't worry you and they have
been around for lees than half the time DOHC has.
Richard
danah...@my-dejanews.com
toml...@ix.netcom.com (Chuck Tomlinson) wrote:
>
> Anyway, the bottom line is performance. If you can get, say, 400 hp
> at 6,500 rpm with a pushrod 16V engine, why spend more money to get
> 400 hp at 8,000 rpm from an OHC engine with smaller displacement but
> has similar weight, external size, and other performance measures?
But if the OHC has the same power as the OHV at a higher RPM, then
you've potentially got a higher top speed with the OHC (using the
same gearing).
And if the powerband of the OHC is broader, then you can optimize
the car's gearing better, leading to better acceleration. So the
performance isn't necessarily similar.
Brandon Sommerville
>How long has DOHC been around?? 90 years if I'm not mistaken.
>To me that's means it's proven.
>
>What about all the hightech gizmos (computers, EFI) that let the LS-1
>produce the power it does. They obviously don't worry you and they have
>been around for lees than half the time DOHC has.
But the engine uses (gasp!) PUSHRODS!!! That's barbaric!
rmoburg
Sommerville) wrote:
>
>But the engine uses (gasp!) PUSHRODS!!! That's barbaric!
Actually they kind of lost their charm when they were no longer
exposed in those little tubes on the outside of the engine.
FStanbach
>
>>So tell me: what *significant* thing is the Northstar doing right,
>>in relation to the LS1?
>
>Using technology to replace displacement thus allowing better
>marketing.
>
>
>GM of course.
>--
>Brandon
>
>Never underestimate the power of
>stupid people in large groups.
I'm impressed by ignition systems. GM has many inovative DIS systems on the
3800, 3300, and 3.8. GM ignitions also run the highest current threw their
primary(8.5). The Northstars and Auroras have cool DIS too. My dads truck has
a pretty standard waste spark coil pack, but whats really impressive is the
ignition is controled by drivers in the EEC V. My all time favorite has to be
the dual plug-dual DIS on some ford 2.3; Although, ford limits it's ignition
primary to 5.5 amps having two DIS coils more than makes up for it. You prolly
could run 95% nitromethane in those things without misfire.
Oodleoff
16v makes the same power if not more without it?
Oodleoff
>Mustang and GM's DOHC engines, this one seems to
>be making good power and torque for it's displacement.
305 HP for a 4.6 isn't good?? I think that is a very nice figure for hp per
liter. But you're right, it ain't the Ferrari
Jeff Reid
1992 ZX-11, 145hp @11500rpm, 85ft-lb @8,000 rpm, 1.056 liters.
Ferrari, 485hp @ 7000rpm, 421ft-lb @5,000 rpm, 5.5 liters
Mustang Cobra, 305hp @ 5800rpm, 300ft-lb @4,800 rpm, 4.6 liters.
(BTW, ZX-11 numbers at rear tire are 130hp and 76ft-lb torque).
I realize that having high rpms make it easier for a
smaller engine to have a good horsepower versus displacement
ratio, but torque per liter should be independent of max
rpms, just good overall engine design.
Torque per liter:
ZX-11 80.5 ft-lb/liter
Ferrari 76.5 ft-lb/liter
Cobra 65.2 ft-lb/liter
It just seems that Ford and GM should be getting more torque
and power out of their DOHC 32V engines. A 4.6 liter DOHC
engine should also be able to handle a lot more rpms than a
5.7 liter pushrod (LT1 and LS1).
Jeff Reid
>
> Actually they kind of lost their charm when they were no longer
> exposed in those little tubes on the outside of the engine.
So that's why they sell so many under-powered, over-vibrating,
over-priced Harleys...
Chuck Tomlinson
>
>The Caddy site [3] also says the '98 STS has a 3.71 rear end (SLS 3.11).
>I found another site [2] which says the Fleetwood with the LT1 had a
>2.56 rear end (sorry, no model year listed) and goes from 0-60 in 8.5
>seconds, significantly slower than the STS (Caddy site claims 6.7).
I'd be surprised if a.a.c.f. readers still give a damn about this
discussion, so feel free to limit future responses to r.a.d. or we
can go to email. Anyway...
The acceleration difference is not surprising, since the STS's power
to weight ratio is ~25% better than the Fleetwood's.
Still, the Fleetwood's heavier weight should penalize it on the EPA
city test, where peak power is not very relevant (AFAIK, neither car
would see WOT let alone peak power in the city test).
And the Fleetwood's weight shouldn't make much difference on the
highway test, where gearing, aero, and engine efficiency are much
more important than weight or peak power.
>Assuming I've got my data correct this time, I think you need to compare
>the LT1/Northstar in cars which at least have similar gearing.
I agree, that would make the comparison more valid. But rear end
ratio doesn't tell the whole story. The engine redline and trans
ratios are also important, and to a lesser extent, tire diameter.
IMHO, I think the cars should be matched on "speed at redline" or
"speed at peak power". Either of those comparison points should
automatically include all the significant gearing factors.
I can find speed-in-gears data for the Seville (the STS, at least),
but I don't think I have that data for the Fleetwood. I may resort
to comparing the STS to the Impala SS. It's not a Cadillac, but
it's larger and heavier than the FWD Caddies (and it's built on the
same platform as the Fleetwood).
--
Chuck Tomlinson
Chuck Tomlinson
>
>I was wrong, (getting my engines mixed up) it's a 5.5 liter
>(332 cubic inches) V12 (used in the Maranello 5.5),
>485 hp at 7,000 rpm, 421 ft-lb at 5,000 rpm.
I agree, that is one wicked engine. But the same points keep coming
up: it is a limited-production, large, fairly heavy, and (no doubt)
extremely expensive engine.
It's really no mystery how to make that much clean, streetable power
with a pushrod Chevy. A pair of SB2 heads on an aluminum 400 block,
and a few choice (but common) aftermarket parts and boom! 485 hp in
a daily driver. I'm describing an engine similar to what LPE built
for Car & Driver. That 7.0-l pushrod Chevy made just over 600 hp in
emissions-clean tune. IMHO, it could get _a lot_ more civilized if
it were built with 120 less hp, don't you think?
Again, I'm not trying to dismiss the 550's engine. That thing makes
me drool every time I stop by Ferrari's web site. But there are
pushrod ways to skin a 485 hp cat (or prancing horse, in this case).
BTW, the beast is at http://www.ferrari.it/vetture/oggi.e/f550c.html
if you haven't slobbered, um, seen it recently.
>Still curious about LT1 performance with a dominion head...
Me too.
--
Chuck Tomlinson
Chuck Tomlinson
>
>But if the OHC has the same power as the OHV at a higher RPM, then
>you've potentially got a higher top speed with the OHC (using the
>same gearing).
Why would you use a different engine but the same gearing? You
wouldn't. It's only sensible to gear the car to suit the engine.
>And if the powerband of the OHC is broader, then you can optimize
^^^^
>the car's gearing better, leading to better acceleration. So the
>performance isn't necessarily similar.
That's a _really_ big "if". The LS1 is relatively peaky (for a
modern production Chevy), but its predecessor (the LT4) has an
extremely flat torque curve. From the driver's seat, an LT4 just
pulls through each gear at a steady rate until it's time to shift.
It would probably be boring if you didn't find yourself on the
handcuff side of 100 mph in less than a dozen seconds.
BTW, if you have access to a technical library, take a peek at SAE
paper #970915. It describes the LS1 in considerable detail.
--
Chuck Tomlinson
Shaman WS6
> >I was wrong, (getting my engines mixed up) it's a 5.5 liter
> >(332 cubic inches) V12 (used in the Maranello 5.5),
> >485 hp at 7,000 rpm, 421 ft-lb at 5,000 rpm.
>
> I agree, that is one wicked engine. But the same points keep coming
> up: it is a limited-production, large, fairly heavy, and (no doubt)
> extremely expensive engine.
With little or no warranty. But still, a very sweet piece of kit.
| Steve's Car Interest Alias - business & personal mail to co...@kos.net SVP |
| 1998 WS6 Formula Firebird, !T-Tops, !2B, !CAGS, !EGR, !0.60, M6, Bright Red|
| 1998 RX-7 One Lap Team (27th) Home Track: Shannonville SVRA Member #4821 |
| Web Sites: http://www.rumour.com/steve/car/ http://onelap.kos.net/ |
Goran Begicevic
with electronic controlled electromagnetic-valve openers became more
common. For time being , BMW is running it's first prototype of cam-less
engine. Well , i really like the idea, not to speak of posibility to
alter valve timing electronically...
MoeChurch
alter perfection!
Life is only as good as the toys you have....
FStanbach
>>
>>> Actually, _all_ the Cadillac Northstar engines are 32V V8s, as is
>>> the Aurora's engine. Those 32V engines, like similar displacement
>>> engines from a certain other Big 3 automaker, are externally larger,
>>> less powerful, more expensive, and no more fuel efficient than the
>>> "primitive" pushrod LS1.
>>
>>The Northstar is 1.1L smaller than the LS-1 yet produces 305hp.
>>Must be doing something right.
>>
>>Richard
Did you guys know the 4.2 L V6 ford F-150 makes 210 hp at 5000 rpm. This
engine is an OHV. In comparison the 4.6 L V8 SOHC engine makes 210 hp at 4400
rpm. That means the OHV is more efficient than the V8.
Jim Wei
In article <hmmmm6umed0.ams.matt@gatekeeper>, ma...@MEC.Edu writes:
|> In article <199808312020...@ladder03.news.aol.com>, Grintloc wrote:
|> >Why would GM put 16 valve small blocks in their new muscle cars (Corvette, F
|> >bodies, etc)? In general, wouldn't more valves per cylinder provide both more
|> >power and better efficiency? Would this be an expensive setup, and thus be the
|> >reason for them not making an engine like this, or something else? Or am I
|> >just way off in my thinking? Just wondering.
|>
|> aren't some of the caddy northstar engines quad overhead cam?
|>
The reason GM is still using 16 valve in the Vette/F-bodies is because the
money poured into research to improve those engines would also benefit the
truck engines. And trucks bring majority of GM's profit.
Jim
P. J. Remner
In a previous article, jim...@bnr.ca (Jim Wei) says:
>
>The reason GM is still using 16 valve in the Vette/F-bodies is because the
>money poured into research to improve those engines would also benefit the
>truck engines. And trucks bring majority of GM's profit.
>
And lots of people are returning their "Brand F" trucks because
"they have to work so hard to go up hills". They aren't working
hard, they make the same HP as the older OHV engines, but people
in this country assume high RPM = engine badly strained. And
they also assume that OHC engines will suck for trucks, so they
stick to the tried-and-true OHV arrangement, soon to be found
only in GM trucks.
--
"and also... and also, i should point out that when i was growing
up as a kid, a lot of people tried to tell me that drugs were cool,
and I found out.... they are."
- rev., WENZ interview 14-9-98
Dean E. Lopez
<6tuiqv$lna$1...@alexander.INS.CWRU.Edu>...
> And lots of people are returning their "Brand F" trucks because
> "they have to work so hard to go up hills". They aren't working
> hard, they make the same HP as the older OHV engines, but people
> in this country assume high RPM = engine badly strained. And
> they also assume that OHC engines will suck for trucks, so they
> stick to the tried-and-true OHV arrangement, soon to be found
> only in GM trucks.
>
???
Dude, I can't tell if your arguing for or against the "tried-and-true OHV
arrangement".
--
Dean E. Lopez lop...@hou.valmet.com
Systems Analyst, RTU Firmware Engineering
Valmet Automation Houston, Texas USA
'98 WHITE TA M6 TT 16"CHROME K&N BORLA EIBACHS
13.42 @ 105.04
jasonvp@@m1ndspr1ng.nospam.com
: stick to the tried-and-true OHV arrangement, soon to be found
: only in GM trucks.
I supposed Dodge will just up and throw that V10 away. Right? Whether you
like it or not, you're correct. The OHV technology *is* tried and true; it
works, it's cheap, and there's really no reason not to use it.
jas
--
Jason Van Patten | subtlety (n) |
jasonvp@@m1ndspr1ng.NOSPAM.com | The art of choosing the lighter |
| sledgehammer. |
Any opinions expressed here are actually yours, you just don't know it. Yet.
To reply to me: jasonvp at mindspring dot com
Timothy R. Sloper
talking about how efficient the DOHCs are and how the OHVs are old
technology. What doesn't get through his head is I (98 Z) whip his ass
almost everytime we race each other. Yeah efficiency is great in a DOHC but
which engine here is the cheapest and easiest to repair, mod, or replace and
has even more performance going for it? did I hear LS1? Right you are
Johnny! DOHC advocates we hace some nice parting prizes for you.. thanks for
playing! I'm an electrical engineer and there is one thing that
differentiates an excellect engineer from an ok engineer. The excellent
engineer will follow the KISS principle (keep is simple stupid) while the ok
engineer will do more than he needs to while costing the customer alot more
money in the long run. When the day arises a OHV engine can't meet the
requirements of the customer (or EPA) then I'm sure GM will goto a DOHC
design but until then why mess with it?! I'm not taking anything from the
DOHC designers, they do a great job but they are overdesigning especially in
the V8 category. For the 4 bangers that type of technology is a great help
to gain economy and performance. Granted the LT5 was DOHC but it was
expensive and the current LS1 is very close on its heals in terms of
performance.
Tim
98 A4 Z28 Arctic White
jasonvp@@m1ndspr1ng.NOSPAM.com wrote in message
<6tukam$i...@spamz.news.aol.com>...
FStanbach
Timothy R. Sloper wrote:
I forgot what it was, but the ohv is lighter and has more cubic inches. The
LS1 has a better ignition system too.
Cobra2442
>I forgot what it was, but the ohv is lighter and has more cubic inches. The
>LS1 has a better ignition system too.
Very true, but how much did GM spend on developing the LS1? If they had spend
the Millions on a OHC or DOHC, I'm sure that it would have made more financial
sense...
Rexford Dundon
1997 Green Cobra Coupe #2442
Richard Fay
>
> I agree with Jas.. my neighbor owns a 98 Cobra (32V DOHC). He is always
> talking about how efficient the DOHCs are and how the OHVs are old
> technology. What doesn't get through his head is I (98 Z) whip his ass
> almost everytime we race each other.
We won't mention the near 30% capacity advantage your car has ......
Think of the power output of the LS-1 if it did have DOHC heads.
Richard
jasonvp@@m1ndspr1ng.nospam.com
: We won't mention the near 30% capacity advantage your car has ......
: Think of the power output of the LS-1 if it did have DOHC heads.
And think of the space required to house a 5.7 liter DOHC V8 engine. It's
already been done; see the LT5. While that engine is certainly a powerful
piece of machinery, it's also *huge* and *heavy*. And hell, if you're going
to start talking engines of that physical size, why not do as Chuck says,
use an alloy Rat in its place. A big 500ci aluminum Chevy will take up
about the same space as the LT5, weigh about the same, and produce
significantly more power.
The LT5 will likely fit under the hood of the Camaro, although I'm not
positive of that. I know a big block Chevy will; Jon Moss has already done
it. He had horsepower numbers over 700 as I recall. Why play with all
those cams? You don't need them for that application (pony cars.)
For a given *displacement* a N/A DOHC engine will outperform a N/A OHV
engine. Displacement figures matter in applications where rules say, "Your
engine must not exceed this displacement figure." We see this in... racing?
And because of that, it's no surprise DOHC engines are so predominant. For
a mass-produced street car, here in the states, the engine choice comes down
to, "What can I *fit* under the hood that'll produce X horsepower, with Y
gas mileage, and last Z miles?" Simple OHV technology in the case of
trucks, pony cars, and even the Corvette seems to fit the bill perfectly.
So again, I ask, why play with all those cams?
Brandon Sommerville
Dennis G. Smith
says...
> >So again, I ask, why play with all those cams?
>
> Marketing.
>
It's sort of galling. A 4.6L, DOHC, all-aluminum V8 should be turning
at least 8,000 rpm, but Ford set the red line at about the same point a
solid lifter, push rod, 396's was set at 30 years ago. This is progress?
I can see the added cost and complexity if they were exploiting the
advantages of the technology, but as it is, it's just a marketing scam.
The LS1 is clearly a better design in the form that the engines are
currently deployed.
Dennis
jasonvp@@m1ndspr1ng.nospam.com
: says...
:>
:> Marketing.
Hehe.. :-) He said it, not me.
In rec.autos.driving Dennis G. Smith <dsm...@eng.uab.edu> wrote:
: It's sort of galling. A 4.6L, DOHC, all-aluminum V8 should be turning
: at least 8,000 rpm, but Ford set the red line at about the same point a
: solid lifter, push rod, 396's was set at 30 years ago. This is progress?
I would bet (again, I'm not positive about this) that the 4.6 could handle
more revs. Ford wanted to meet a certain horsepower number with that
engine, in that car, so they "blocked" the intake and exhaust. The
unfortunate results are an engine that starts gasping up near its 6500RPM
redline.
I would think if you took the engine, port and polished the heads,
opened up the manifold, and freed up the exhaust a little, it'd shine past
its current redline/cutoff. As I understand it, a few folks have
experimented with superchargers on the 4.6, and are finding that the
horsepower curve doesn't drop off before the fuel cut-off. The engine
clearly can use the air, if it can get it.
But whoever heard of revving a pony car up to 8000RPMs?
: I can see the added cost and complexity if they were exploiting the
: advantages of the technology, but as it is, it's just a marketing scam.
Agreed for the most part. There were rumors (perhaps from Ford itself,)
that they were having trouble getting the 302 up to snuff for the upcoming
ODB-2/3 and other emmissions restrictions. Their answer was to stuff the
4.6 into the Stang. I dunno how true this is though.
: The LS1 is clearly a better design in the form that the engines are
: currently deployed.
Agreed again. If your goal is a high-revving racing-rocket of an engine,
then a DOHC is probably the answer for you. However, for most street and
off-road(trucks) applications, the LS1 and other OHV engines are an
inexpensive, lightweight, and powerful package.
Chuck Tomlinson
>gri...@mindless.moc says...
>> >So again, I ask, why play with all those cams?
>>
>> Marketing.
>
>at least 8,000 rpm, but Ford set the red line at about the same point a
>solid lifter, push rod, 396's was set at 30 years ago. This is progress?
The Cobra engine does have a fairly long stroke, so the Ford guys
have to think about piston and ring durability. The average piston
speed in the Cobra engine is already higher than the LS1's, and
raising redline to 8,000 rpm would put average piston speed above
4,700 fps. AFAIK, very few street cars go that high. The only one
I can think of is the little 1.8L Integra Type R engine.
>I can see the added cost and complexity if they were exploiting the
>advantages of the technology, but as it is, it's just a marketing scam.
>The LS1 is clearly a better design in the form that the engines are
>currently deployed.
I agree that the LS1 has the clear advantage now. The Ford design
could give the LS1 a run for its money, but I cannot understand why
Ford doesn't get more of the potential out of the DOHC. The rumors
I hear about the '99 Cobra all involve superchargers or larger
displacement. WTF?
Sometimes I wonder why Ford didn't just cast up some 351Ws in
aluminum and call it good. They would've saved a fat chunk of
change and the Mustang would probably be even faster than it is now.
--
Chuck Tomlinson
Josh Turner
>
> : In article <36050ca1...@news.powersurfr.com>, gri...@mindless.moc
> : says...
> :>
> :> Marketing.
>
> Hehe.. :-) He said it, not me.
>
> In rec.autos.driving Dennis G. Smith <dsm...@eng.uab.edu> wrote:
> : at least 8,000 rpm, but Ford set the red line at about the same point a
> : solid lifter, push rod, 396's was set at 30 years ago. This is progress?
>
> more revs. Ford wanted to meet a certain horsepower number with that
> engine, in that car, so they "blocked" the intake and exhaust. The
> unfortunate results are an engine that starts gasping up near its 6500RPM
> redline.
>
> I would think if you took the engine, port and polished the heads,
> opened up the manifold, and freed up the exhaust a little, it'd shine past
> its current redline/cutoff. As I understand it, a few folks have
> experimented with superchargers on the 4.6, and are finding that the
> horsepower curve doesn't drop off before the fuel cut-off. The engine
> clearly can use the air, if it can get it.
>
> But whoever heard of revving a pony car up to 8000RPMs?
Heh. Imagine a Honda VTEC, except it's a V8 and makes 350 hp. Now
THERE'S an engine I'd buy.
> : I can see the added cost and complexity if they were exploiting the
> : advantages of the technology, but as it is, it's just a marketing scam.
>
> Agreed for the most part. There were rumors (perhaps from Ford itself,)
> that they were having trouble getting the 302 up to snuff for the upcoming
> ODB-2/3 and other emmissions restrictions. Their answer was to stuff the
> 4.6 into the Stang. I dunno how true this is though.
(Donning Nomex suit)
I've had several Mustangs over the years, with both the 302 and the 4.6.
While it might be true that the LS1 is a better engine than the DOHC 4.6
(as I haven't yet driven an LS1-equipped car, I reserve judgment), the
old Ford 302 in stock form is not nearly as nice an engine as even the
new SOHC 4.6. Driving the 4.6 and the 302 back-to-back, it becomes
apparent that the 4.6 breathes better, and has a broader powerband than
the 302. The 302 has more oomph at low rpm, but this advantage quickly
disappears, at least IMHO, when the tach passes about 2K rpm. The DOHC
4.6, of course, is in another category altogether, and puts the 302 on
the trailer in every important performance respect.
Now, I realize that with modifications, the 302 can be opened up to
breathe better, and it is easier to modify than the 302, etc. But in
stock form, the 4.6 is a better engine.
All of that aside, I think emissions was another thing that did in the
302, though it continues to soldier on in the Explorer/Mountaineer, in
slightly detuned form (using some pieces from the truck edition of that
engine).
I absolutely agree that marketing played a role in the decision to make
a DOHC version of the 4.6. However, I don't think marketing really
played that big a role in Ford's decision to use it in the Mustang. Keep
in mind that while GM could justify the creation of a new
high-performance pushrod V8 because of the Corvette (and pass on those
goodies to the F-bodies), Ford has no similar loss-leading image car for
which it can justify spending gads of money. The Mustang, despite
selling far better than either of the F-bodies, is not exactly pulling
in money hand over fist--and if you look solely at Cobra sales, the
numbers get even worse. By all accounts, it was by the narrowest of
margins that the Mustang survived the house cleaning that went on this
year in the Ford product lineup--had it been anything other than an
American icon, it almost certainly would have gone the way of the Probe,
Thunderbird, Aerostar, etc. So you can imagine how difficult it would be
for the product guys to get funding approved for the development of a
new engine unique to the Mustang, even if it was just an evolution of
the 5.8.
At the same time, the development work on the DOHC 4.6 could be spread
between at least three different product lines--the Mark VIII, the
Continental, and the Mustang. Hell, most of the development cost could
also be shared with the SOHC iteration, which Ford has put into
everything that moves. This engine (the DOHC) was one that Ford had to
build anyway, if Lincoln was to compete with the Toyota 4.0, the Nissan
4.x, the Northstar, etc--and, of course, one of the main considerations
there *was* marketing. So this hot rod Lincoln motor was selected for
the hi-po Mustang, rather than building a new pushrod engine a la LS1.
IOW, Ford built one engine and used it across the board, whereas GM
spent more and built two--the LS1 and derivatives, and the Northstar and
derivatives.
Chuck Tomlinson
>
>Heh. Imagine a Honda VTEC, except it's a V8 and makes 350 hp. Now
>THERE'S an engine I'd buy.
It's waiting for you at your neighborhood Ferrari dealer :-)
>Driving the 4.6 and the 302 back-to-back, it becomes
>apparent that the 4.6 breathes better, and has a broader powerband than
>the 302. The 302 has more oomph at low rpm, but this advantage quickly
>disappears, at least IMHO, when the tach passes about 2K rpm. The DOHC
>4.6, of course, is in another category altogether, and puts the 302 on
>the trailer in every important performance respect.
The stock 5.0's tuning was purely a matter of tuning. Back in the
mid-80's, the emphasis was on midrange power. Remember the GM TPI
V8s from that era (the ones with the spider-like intake manifold)?
Just like the 5.0, they pulled hard in the midrange, then fell flat
on their faces.
But the major power-making differences between the old TPI engines
and the LT1/LT4 engines were the manifolds and the heads, which were
cast with reasonable flow properties. There is absolutely no reason
why Ford could not have done the same with the 5.0. Hot rodders
(Ford and GM) do it every day, with aftermarket heads and manifolds.
>I absolutely agree that marketing played a role in the decision to make
>a DOHC version of the 4.6. However, I don't think marketing really
>played that big a role in Ford's decision to use it in the Mustang. Keep
>in mind that while GM could justify the creation of a new
>high-performance pushrod V8 because of the Corvette (and pass on those
>goodies to the F-bodies), Ford has no similar loss-leading image car for
>which it can justify spending gads of money. [...]
The LS1 was also developed into truck engines, which must have made
the business case a lot easier to make. BTW, the strongest truck
version of the LS1 (the 6.0) has only 5 hp less than the DOHC Cobra
engine! With iron heads and block, it definitely weighs more, but
it's still the same external size as the car LS1s (i.e. much smaller
than the Ford).
>At the same time, the development work on the DOHC 4.6 could be spread
>between at least three different product lines--the Mark VIII, the
>Continental, and the Mustang. Hell, most of the development cost could
>also be shared with the SOHC iteration, which Ford has put into
>everything that moves. This engine (the DOHC) was one that Ford had to
>build anyway, if Lincoln was to compete with the Toyota 4.0, the Nissan
>4.x, the Northstar, etc--and, of course, one of the main considerations
>there *was* marketing.
I agree totally. Ford had absolutely no choice but to supply luxury
shoppers with a mid-4L 4V "me-too" V8. In the Mustang, I guess the
SOHC 2V 4.6 would be hard pressed to compete with the GM pushrod
offerings (smaller displacement, but similar stroke and valvetrain
weight). So that left them only the giant 4V DOHC.
Whew... rough call but IMHO, after being backed into a corner like
that, they could've squeezed a little more power out of the beast
(to make the effort worthwhile by giving GM some real competition).
>IOW, Ford built one engine and used it across the board, whereas GM
>spent more and built two--the LS1 and derivatives, and the Northstar and
>derivatives.
Sounds reasonable.
--
Chuck Tomlinson
Josh Turner
>
> sh...@umich.edu wrote:
> >
> >Heh. Imagine a Honda VTEC, except it's a V8 and makes 350 hp. Now
> >THERE'S an engine I'd buy.
>
> It's waiting for you at your neighborhood Ferrari dealer :-)
Tell me about it.
> >Driving the 4.6 and the 302 back-to-back, it becomes
> >apparent that the 4.6 breathes better, and has a broader powerband than
> >the 302. The 302 has more oomph at low rpm, but this advantage quickly
> >disappears, at least IMHO, when the tach passes about 2K rpm. The DOHC
> >4.6, of course, is in another category altogether, and puts the 302 on
> >the trailer in every important performance respect.
>
> The stock 5.0's tuning was purely a matter of tuning. Back in the
> mid-80's, the emphasis was on midrange power. Remember the GM TPI
> V8s from that era (the ones with the spider-like intake manifold)?
> Just like the 5.0, they pulled hard in the midrange, then fell flat
> on their faces.
>
> But the major power-making differences between the old TPI engines
> and the LT1/LT4 engines were the manifolds and the heads, which were
> cast with reasonable flow properties. There is absolutely no reason
> why Ford could not have done the same with the 5.0. Hot rodders
> (Ford and GM) do it every day, with aftermarket heads and manifolds.
Yes, but I think this is where OBDII rears its head. Emission certifying
the 302 with new heads, manifolds, etc. probably would have been costly,
especially when you consider that there is already a SOHC 4.6 in the
pipe, and that even with really great design, the resulting 302 Mustang
still would have been slower than the 350 cid Camaros. If you're going
to spend money, you'd better get something in return.
> >I absolutely agree that marketing played a role in the decision to make
> >a DOHC version of the 4.6. However, I don't think marketing really
> >played that big a role in Ford's decision to use it in the Mustang. Keep
> >in mind that while GM could justify the creation of a new
> >high-performance pushrod V8 because of the Corvette (and pass on those
> >goodies to the F-bodies), Ford has no similar loss-leading image car for
> >which it can justify spending gads of money. [...]
>
> The LS1 was also developed into truck engines, which must have made
> the business case a lot easier to make. BTW, the strongest truck
> version of the LS1 (the 6.0) has only 5 hp less than the DOHC Cobra
> engine! With iron heads and block, it definitely weighs more, but
> it's still the same external size as the car LS1s (i.e. much smaller
> than the Ford).
True. The same holds true for the Romeo V8, though--there is very little
difference between the SOHC V8 in the Mustang and the 4.6 in the F-150s,
Expos, etc, and as I understand it, the 5.4 is simply a stroked version
of that engine. So Ford got even more economy out of the modular design,
by sharing it with 700,000 F series as well. OTOH, I think that now that
the new LS1 based GM truck engines are hitting the road, Ford is
regretting going the SOHC route for their engines--it sounds from most
of the comparos that the "Triton" engines are noticeably outclassed by
their GM competition in terms of power, and show little or no
corresponding fuel efficiency gain. Of course, the way around this is to
just get one of those V-10s--hey, wait a minute, *there's* the engine
that should be in the Cobra! <g>.
What's bizarre is the new Lincoln LS, which uses a detuned Jaguar 4.0
liter rather than the Lincoln/Romeo 4.6. I haven't seen the LS up close,
obviously, and I have no idea what the relative size figures of the
engines are, but it seems a bit silly not use the Romeo engine, esp. now
that the Mark VIII has been discontinued. OTOH, platform commonality
means that by using the Jag engine, they only have to design one
transmission, wiring harness, etc. And it leaves open the rather
titillating concept of a Lincoln LSVT, with the supercharged engine from
the XKR/XJR. With 370 hp, that's a car that would make even the new M5
take note.
> >At the same time, the development work on the DOHC 4.6 could be spread
> >between at least three different product lines--the Mark VIII, the
> >Continental, and the Mustang. Hell, most of the development cost could
> >also be shared with the SOHC iteration, which Ford has put into
> >everything that moves. This engine (the DOHC) was one that Ford had to
> >build anyway, if Lincoln was to compete with the Toyota 4.0, the Nissan
> >4.x, the Northstar, etc--and, of course, one of the main considerations
> >there *was* marketing.
>
> I agree totally. Ford had absolutely no choice but to supply luxury
> shoppers with a mid-4L 4V "me-too" V8. In the Mustang, I guess the
> SOHC 2V 4.6 would be hard pressed to compete with the GM pushrod
> offerings (smaller displacement, but similar stroke and valvetrain
> weight). So that left them only the giant 4V DOHC.
>
> Whew... rough call but IMHO, after being backed into a corner like
> that, they could've squeezed a little more power out of the beast
> (to make the effort worthwhile by giving GM some real competition).
Agreed. And if the numbers that the guys on the F-body list are throwing
around are accurate (about wheel dyno figures), it looks like Ford is
perhaps being optimistic about their power figures, whereas GM is
understating the WS6/SS numbers somewhat in order to avoid treading into
Corvette territory--though I still have a hard time accepting this "ram
air" concept. It seems to me that a 4.6 V8 should be able to make more
than 305 hp with DOHC, although Toyota had to go to VVT in order to get
300 out of a 4.0 liter engine. We'll see what '99 brings.
Chuck Tomlinson
>
>Yes, but I think this is where OBDII rears its head. Emission certifying
>the 302 with new heads, manifolds, etc. probably would have been costly,
>especially when you consider that there is already a SOHC 4.6 in the
>pipe, and that even with really great design, the resulting 302 Mustang
>still would have been slower than the 350 cid Camaros.
Yeah, probably. I think I know what Ford was trying to do with the
modular engine idea, but it seems to me that GM's plan works at
least as well. As you said, GM has two families of "small" V8s --
the Northstar and the Gen III small-block. And they still have the
big-block family (now in its 3rd generation).
Between the Cadillacs and Auroras, I've gotta think that the
Northstar sees enough sales volume to be down near the flat part of
the cost vs. volume curve. Needless to say, the Gen III pushrod
engine will quickly reach that point, with all the truck sales.
So it's not clear to me how Ford benefited from choosing *not* to
have a compact pushrod engine family that would be fine for trucks
and Mustangs, while leaving the OHC family to its large cars.
>True. The same holds true for the Romeo V8, though--there is very little
>difference between the SOHC V8 in the Mustang and the 4.6 in the F-150s,
>Expos, etc, and as I understand it, the 5.4 is simply a stroked version
>of that engine. So Ford got even more economy out of the modular design,
>by sharing it with 700,000 F series as well.
True, but I suspect that the modular engines are more expensive than
pushrod engines (for the extra material and machining, if nothing
else). The Monday morning QB question is: could the OHC engines
have seen enough volume in Ford's large cars to be economically
feasible? If not, then perhaps Ford did the right thing by
swallowing the extra size and cost of the OHC family in all its
large car and truck platforms.
>What's bizarre is the new Lincoln LS, which uses a detuned Jaguar 4.0
>liter rather than the Lincoln/Romeo 4.6. I haven't seen the LS up close,
>obviously, and I have no idea what the relative size figures of the
>engines are, but it seems a bit silly not use the Romeo engine, esp. now
>that the Mark VIII has been discontinued.
Not really. The Lincoln LS would give the Jaguar engine a boost in
manufacturing volume, while making a relatively minor impact on the
total volume of the Romeo V8s. It's similar, I guess, to GM's
decision to put a Northstar in the Aurora, rather than using the
same 3800SC that's in the Aurora's original sister car (the Riv).
>Agreed. And if the numbers that the guys on the F-body list are throwing
>around are accurate (about wheel dyno figures), it looks like Ford is
>perhaps being optimistic about their power figures, whereas GM is
>understating the WS6/SS numbers somewhat in order to avoid treading into
>Corvette territory--though I still have a hard time accepting this "ram
>air" concept.
I haven't seen a C5 and an LS1 F-body dynoed back-to-back, but so
many people have that I'm pretty certain the LS1 F-bodys are every
bit as powerful as the C5s. GM must know that, but I don't know why
they feel they have to advertise the F-body's power as lower than
the Vettes. The price difference between the two is large enough
that I don't think 25 hp would sway many people away from Vettes.
Of course, I'm no marketing guru...
As for the Ram Air thing, I'm pretty sure it's just less restrictive
than the stock intake plumbing. The increase is ram pressure is
pitifully small at street speeds (about 1% at 100 mph, and 5% at
200 mph, IIRC).
--
Chuck Tomlinson
P. J. Remner
In a previous article, lop...@hou.valmet.com (Dean E. Lopez) says:
>P. J. Remner <aj...@cleveland.Freenet.Edu> wrote in article
><6tuiqv$lna$1...@alexander.INS.CWRU.Edu>...
>
>> And lots of people are returning their "Brand F" trucks because
>> "they have to work so hard to go up hills". They aren't working
>> hard, they make the same HP as the older OHV engines, but people
>> in this country assume high RPM = engine badly strained. And
>> they also assume that OHC engines will suck for trucks, so they
>> stick to the tried-and-true OHV arrangement, soon to be found
>> only in GM trucks.
>>
>
>???
>Dude, I can't tell if your arguing for or against the "tried-and-true OHV
>arrangement".
>
Neither. I'm stating what I know.
Personally, I wouldn't give a rip. 215hp is 215hp whether it makes it at
4400 or 5600, and if I have to rev it higher, so be it. Of course, there
are arguments for engine longevity in larger engines, or better MPG under
light loads with smaller engines... but the point is that I don't really
see myself owning a truck for any purpose!
And yes, I finally put a down payment on that '87 RX Turbo!
P. J. Remner
In a previous article, "jasonvp@"@m1ndspr1ng.NOSPAM.com () says:
>In rec.autos.driving P. J. Remner <aj...@cleveland.Freenet.Edu> wrote:
>: stick to the tried-and-true OHV arrangement, soon to be found
>: only in GM trucks.
>
>I supposed Dodge will just up and throw that V10 away. Right? Whether you
>like it or not, you're correct. The OHV technology *is* tried and true; it
>works, it's cheap, and there's really no reason not to use it.
I believe they are designing a new one based off of the 4.7l, forgot where
I got that rumour.
Something in the 6.0l range? To make the same HP as the old V10.
Also to be found in the Viper (maybe in DOHC format?). Should
lighten that load!
Dennis G. Smith
says...
> I agree that the LS1 has the clear advantage now. The Ford design
> could give the LS1 a run for its money, but I cannot understand why
> Ford doesn't get more of the potential out of the DOHC. The rumors
> I hear about the '99 Cobra all involve superchargers or larger
> displacement. WTF?
There are only so many things you can do to make more power. More revs,
more displacement or adding a blower. All of these have an effect on
reliability and/or gas mileage. I think Ford is having a hard time making
up its mind how it wants to proceed with this.
GM's new V6 is a real thorn in Ford's side. The 3.5L engine likes to rev
like crazy and with a 6 psi Eaton blower, can probably make 285 - 300 hp.
Even Chrysler's NA 3.5L V6 makes over 250 hp. The LS1 is clearly capable
of 450 hp NA (as will be seen in the new Vette "Viper Killer.") Ford is
probably trying to decide a) whether they want to play and b) if so, how.
My guess is that Ford wishes the whole horsepower issue would just go
away.
> Sometimes I wonder why Ford didn't just cast up some 351Ws in
> aluminum and call it good
They couldn't get that design past the Smog Police, plus the 351 is a gas
hog (not important with gas near $1 a gallon, but CAFE is still with us.)
Dennis
Josh Turner
>
> In article <6u3fme$s...@sjx-ixn10.ix.netcom.com>, toml...@ix.netcom.com
> says...
>
> > I agree that the LS1 has the clear advantage now. The Ford design
> > could give the LS1 a run for its money, but I cannot understand why
> > Ford doesn't get more of the potential out of the DOHC. The rumors
> > I hear about the '99 Cobra all involve superchargers or larger
> > displacement. WTF?
>
> There are only so many things you can do to make more power. More revs,
> more displacement or adding a blower. All of these have an effect on
> reliability and/or gas mileage. I think Ford is having a hard time making
> up its mind how it wants to proceed with this.
More air. The 4.6 SOHC gained 35 hp this year using mainly changes to
the intake. I think the argument is that with detail improvements like
these, the 4.6 DOHC as it stands now could make much better than its
current horsepower.
> GM's new V6 is a real thorn in Ford's side. The 3.5L engine likes to rev
> like crazy and with a 6 psi Eaton blower, can probably make 285 - 300 hp.
> Even Chrysler's NA 3.5L V6 makes over 250 hp. The LS1 is clearly capable
> of 450 hp NA (as will be seen in the new Vette "Viper Killer.") Ford is
> probably trying to decide a) whether they want to play and b) if so, how.
> My guess is that Ford wishes the whole horsepower issue would just go
> away.
Oh, I don't know. The GM Shortstar likes to rev, and may be able to make
some good power with a supercharger, but in its current NA form, it only
makes 215 hp, or 61 hp/L--a far cry from the 253 developed by Chrysler's
new 3.5 (72 hp/L), and, volume for volume, nowhere near as good as
either Ford Duratec V6--the 2.5L makes 170 (200 in SVT form, 68 and 80
hp/L, respectively), while the 3.0L makes 200 (67 hp/L--and it will
likely be closer to 220 hp and 73 hp/L in the forthcoming Lincoln LS).
And talk about loving to rev--all three of these engines (2.5, 2.5 SVT,
and 3.0) are quite happy (some might say ecstactic) in the upper reaches
of the rev band.
Now, Chuck has made a convincing case that volumetric efficiency is
irrelevant in comparing the DOHC 4.6 with the LS1, and I agree--the LS1
is actually physically smaller than the DOHC V8, and thus for packaging
reasons is arguably a better choice. However, volumetric efficiency
is/can be relevant when comparing two or three DOHC V6s, which are
likely very similar in exterior size. Actually, I would be very
surprised if the Ford Duratecs (which externally are quite similar to
each other) weren't substantially smaller than the new Shortstar in
total size, but I have no data on this point. I simply don't see the
purported GM superiority in the V6 arena.
As to whether the whole horsepower issue will go away, with the death of
the F-cars it will whether Ford wants it to or not.
Blah
>Timothy R. Sloper wrote:
>>
>> I agree with Jas.. my neighbor owns a 98 Cobra (32V DOHC). He is always
>> talking about how efficient the DOHCs are and how the OHVs are old
>> technology. What doesn't get through his head is I (98 Z) whip his ass
>> almost everytime we race each other.
>
>
>Think of the power output of the LS-1 if it did have DOHC heads.
>
Efficiency? The LS1's are doing quite well with simple OHV technology -- I
routinely get very high 20's MPG on the highway...
Brian Grimal
Black 98 Formula M6, TT, Chrome, !MAF