[GMCnet] Roller Camshaft

[Espen Heitmann]

ny recommendations ? I have been thinking of the Crane 809611 does anyone have any experience with it ?
--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

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[Johnny Bridges]

Jim Bounds and his engine builder are the gurus of roller cams. Ask him.

--johnny
--
'76 23' transmode Norris upfit
Braselton, Ga.

"Sometimes I wonder what tomorrow's gonna bring when I think about my dirty life and times" --Warren Zevon

[John Wright]

I would suggest that you contact Jim B at the Coop for the cam that is designed for the GMC.

http://www.gmccoop.com/koba_built_motors.htm

Scroll down and look at the info and specs on the “Kryptonite Cam”. Pricing would be about the same, but this cam works for our motors.

JR Wright

[Bill Wevers]

Loffen,
From what I understand, the best RV cams have no more than 204/214 (intake/exhaust) duration at 0.050" lift and 110º or 112º lobe centers for good
low RPM torque.

The Crane you mentioned has 214/222 duration at 0.050" lift and would have a hot rod, rough idle, for more power at high rpm, if that's what you
want.
And you will probably need high performance rocker arms and springs to go with the high lift profile .520/.542 lift.
And also 3.70s or 4.10 gears.
This Crane cam would probably have less power from idle to 2500RPM, than the stock cam.

I believe these are the specs for the stock 455 camshaft :
Part # -OVRLP--Dur----lift------
400117 44 258/272 .435/.435 455 Irrig, Mar, hi-comp ex Pol.,Toro, hi-perf.

For my personal choice I decided to save some $$ and go with a flat-tappet 1984 Hurst Olds camshaft with 194/207 duration (CS651).
It has excellent off-idle torque up to 3000 RPM. It has slightly more lift and duration than the stock camshaft.
Sealed Power CS651 Cam
----CS651 61 275/289 .437/.437 ILC=108 ELC=110
@ 0.050"-----194/207

Here's some information from Lunati:
----------------...@0.50"----
-------------------- Int/Exh----Int/Exh----Lift----------LCA
LUN-10420211 262/262 207/207 .461/.461 112/106 Idle to 5000
LUN 10420285 260/260 210/210 .470/.470 110 smooth idle
LUN 10420700 250/256 207/213 .466/.485 112 towing applications. Good idle.
LUN 10420701 256/262 213/219 .485/.499 112 Fair idle, good torque low to mid range

Regards,
Bill

[lenze middelberg]

Talked to Dick Paterson about rolercam. He thinks they are a wast of money under motorhome conditiond
--
Appie
eleganza 76 "Olga" ( pictures at http://www.gmcmhphotos.com/photos/g6489-olga.html
Volvo v70
Denmark

[Espen Heitmann]

Yes it is a bit in the upper range, the reason for going with the Crane roller is that you can run with a std distributor gear and there might be
possible to advance it 4 degrees to lower the power band.
I will also have a 3.42 final drive and that will help a little together with rising the compression a point or so.

I know some will say that a roller is a waste of money on a RV, I do not agree, less friction and wear, better lobe profiles together with the oil
quality are some of the reasons, I sent an email to Crane so let's see what they say.

I am also pretty sure someone here are using that camshaft and was hoping he would come through and share his experience.

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Neil Martin]

If you go to Crane's webpage, you'll see their mildest roller cam, which I got for my rebuild. Works just fine. Better than stock? Who knows?
--
Neil
76 Eleganza
Los Angeles

[Espen Heitmann]

Thanks Neil

That is the cam I am looking at to, any problems at all ?

http://www.cranecams.com/274-275.pdf

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Espen Heitmann]

How is the idle, acceleration,, cruise rpm, any vacuum readings ?

[Keith V]

I have the flat tappet lifter JIm B recommends.
I've always wondered if the roller was any better at low lifts, low RPM.
I must say that the cam I have sure sounds pretty at idle :)
Not a lope, but a good strong heartbeat
--
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
69 Vette
29 Dodge

[James Hupy]

The principal advantage in roller cams today is longevity. Lift is lift,
duration is duration, rollers allow steeper opening ramp angles. The fly in
the soup today is the lack of wear additives in modern oils. Flat tappet
cams are right on the edge of durability without zinc and phosphorous in
the oil. Especially during break in. Read any cam mfg. stuff. They know.
Jim Hupy
Salem, Oregon
78 GMC ROYALE 403

[Keith V]

James Hupy wrote on Tue, 24 February 2015 11:23

> The principal advantage in roller cams today is longevity. Lift is lift,
> duration is duration, rollers allow steeper opening ramp angles. The fly in
> the soup today is the lack of wear additives in modern oils. Flat tappet
> cams are right on the edge of durability without zinc and phosphorous in
> the oil. Especially during break in. Read any cam mfg. stuff. They know.
> Jim Hupy
> Salem, Oregon
> 78 GMC ROYALE 403

> On Feb 24, 2015 9:06 AM, "Keith V" wrote:
>
> > I have the flat tappet lifter JIm B recommends.
> > I've always wondered if the roller was any better at low lifts, low RPM.
> > I must say that the cam I have sure sounds pretty at idle :)
> > Not a lope, but a good strong heartbeat
> > --
> > Keith Vasilakes
> > Mounds View. MN
> > 75 ex Royale GMC
> > 69 Vette
> > 29 Dodge
> >
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

I dunno, a flat tappet cam will last pretty long if broken in right and used with good oil.
I plan on upping the zinc for the foreseeable future

[Les Burt]

Roller lifters are not necessarily longer lived. Google roller lifter failures and you should find lots of reading material. I am going through such situation right now with my 6.4 powerstroke. They are notorious for having rollers flat spot and wipe out cam lobes. If not caught immediately, it has the potential for scrapping the block as well due to the lifter body swelling and jamming in the bore.

Not to knock what Koba and JimB have developed, but I would be concerned about the longevity of custom aftermarket parts that have very little development time in comparison to what a production line engine has undergone. I think I'd prefer banking my money on a flat tappet cam in my 455.

Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)

[Larry]

Les Burt[1
> wrote on Tue, 24 February 2015 13:25]Roller lifters are not necessarily longer lived. Google roller lifter failures and you should find lots of

> reading material. I am going through such situation right now with my 6.4 powerstroke. They are notorious for having rollers flat spot and wipe out
> cam lobes. If not caught immediately, it has the potential for scrapping the block as well due to the lifter body swelling and jamming in the bore.
>
>
> Not to knock what Koba and JimB have developed, but I would be concerned about the longevity of custom aftermarket parts that have very little
> development time in comparison to what a production line engine has undergone. I think I'd prefer banking my money on a flat tappet cam in my 455.
>
> Les Burt

Les makes a good point. This next statement is not based on fact...just my observation and
experienced opinion. The more you modify a motor...away from the original
design the less reliable it is likely to be. Generally speaking the factory design's
motors to get well past the warrantee period. So, standards and tolerances at the
assembly line are closely watched. That stock motor is really put together right.
If they didn't, imagine the money and business they would loose to bad
reputation. They also build for "worst possible senerios"...the guy that never
changes the oil, because he is going to trade it at 50K anyway. So a certain
amount of durability is essential. JMHO

--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

[Espen Heitmann]

On the other hand I so is there engines that have been in daily use for 30 years or more with roller lifters with out any problems, and one of my
buddies has used the same roller rockers for 20 years with out failure, what I am trying to say is that it goes both ways and engine development has
moved forward since the 70s so I am not to worried about using a roller camshaft

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Rob Mueller]

Espen,

Heads up - you're going to have to machine the lifters to clear the bottom of the OEM intake manifold on a 455.

http://www.gmccoop.com/koba_built_motors.htm

Scroll down until you come to Oil Supply and there you will find a photo showing how the lifters have been "scalloped."

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Gmclist [mailto:gmclist...@temp.gmcnet.org] On Behalf Of Espen Heitmann
Sent: Tuesday, February 24, 2015 2:52 PM
To: gmc...@temp.gmcnet.org
Subject: Re: [GMCnet] Roller Camshaft

On the other hand I so is there engines that have been in daily use for 30 years or more with roller lifters with out any problems,
and one of my buddies has used the same roller rockers for 20 years with out failure, what I am trying to say is that it goes both
ways and engine development has moved forward since the 70s so I am not to worried about using a roller camshaft
--

[Les Burt]

Espen, I totally agree with what you have said. The same logic also applies to how flat tappet engines are surviving with today's oils. You will always find enough documented failures of both lifter designs to justify an argument as to which is superior. Truth is, both are very reliable, and both can fail for various reasons. What I see as the real difference between the systems as applied to Motorhome use is the initial cost of the parts and machining. Roller lifter set-ups can cost over double that of a comparable flat tappet set-up, and both will give you 8-10 mpg.

Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)

[Carl Stouffer]

Everyone I know that is running the Comp Cams "Kryptonite" cam, developed for the GMC Motorhome by Jim Bounds, Richard Archer, Steve Ferguson, and
others, is VERY happy with it's performance either as a roller or flat tappet cam. My engine is completely stock, except for a Cloyes Timing chain
and a Rockwell intake, but I plan to run the Comp cam when it becomes necessary to rebuild.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.

[Espen Heitmann]

Rob, yes on some lifters you will need to grind them a little bit to make them fit, but I have seen others that do look like they will clear the
intake.

I am thinking of going with the Alu intake and it would be nice to know if they did rise the runners or if there is enough material to grind scalops
in it

USAussie wrote on Wed, 25 February 2015 01:33

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Espen Heitmann]

I agree with you Les and it is hard to justify the cost for a roller setup,for me it is more to go all the way, I will use Alu heads and intake
anyways to save weight and rise the compression since the cost is minimal over low compression pistons and it will not be any problems to do so with
our regular fuel.
Then in my mind the engine is more or less ready for a roller camshaft, so why not take use of the benefits that it has over a regular cam ? yes there
is the price issue but othere than that I can not see any bad sides of a roller.

Les Burt[1
> wrote on Wed, 25 February 2015 02:12]Espen, I totally agree with what you have said. The same logic also applies to how flat tappet engines are

[James Hupy]

Espen, unless you go to 4:10 final drive gearing, most of the mods that you
are talking about doing will benefit you very little. If you want higher
compression, change the pistons and leave the "J" heads in place. Do a good
3 angle valve job, keep the seat width around 1 mm, match the port
openings to the gaskets, use a camshaft design that favors low end torque.
Align bore the crank bores and balance the rotating and reciprocating
parts. Torque everything correctly, be fastidious when assembling it, break
it in very carefully, then drive it like you stole it.
Enjoy it for the places it can transport you and family to.
Jim Hupy
Salem, Or
78 GMC Royale 403

[Rob Mueller]

Espen,

Here's a link to 108 photos that show how the Rockwell Aluminum manifold was made:

http://www.gmcmhphotos.com/photos/g3738-gmc-intake-manifold-project.html

Regards,
Rob M.
The Pedantic Mechanic

USAussie - Downunder
USA '75 Avion - Double Trouble TZE365V100426
AUS '75 Avion - The Blue Streak TZE365V100428

-----Original Message-----
From: Gmclist [mailto:gmclist...@temp.gmcnet.org] On Behalf Of Espen Heitmann
Sent: Wednesday, February 25, 2015 5:56 AM
To: gmc...@temp.gmcnet.org
Subject: Re: [GMCnet] Roller Camshaft

Rob, yes on some lifters you will need to grind them a little bit to make them fit, but I have seen others that do look like they
will clear the intake.

I am thinking of going with the Alu intake and it would be nice to know if they did rise the runners or if there is enough material

to grind scallops in it

[Bill]

I would go with a little less duration and less valve lift. The lesser valve lift for Valvetrain reliability. And you don't need the lift for the
torque you want to produce at the rpm you normally run at.

I built a 489 BBC with duration and lift similar to what you are looking at and it was amazing however at 2200 rpm the 455's torque would probably
only be similar to a stock 455, however you should have close to 450 hp at 5500 rpm, how often do you need that?

A roller cam will give you more torque and Hp, they flow more air compared to a flat tappet because the valves open wider sooner and close wider
later. Tearing off a flat tappet lobe can ruin an engine completely in short order and yes adding zink reduces that chance but I have herd of guys
ruining their engines on cam break in, stuff happens. So I agree if you can afford to run a roller, run one!

The edelbrock heads, they look like they have some nice advantages if you have the money, price not bad. Heart shape combustion chamber. Nice,
pedestal rockers, nice. Smaller runners help torqu but it would be nicer to have a better exhaust than the J head and perhaps the better combustion
chamber and exhaust port would overcome the larger intake port. You want bottom end torque, your going to spend most of your time 1500 to 3000 rpm and
it should still be way better at higher rpm so cam it for rpm you run most at. Guys put in larger duration cams to bleed off compression pressure so
they can run higher compression. You are not going to increase torque that much by raising compression but running regular gas you can't have a low
duration torque cam that gets you into detonation.

Compression, take a look at
https://www.uempistons.com/index.php?main_page=calculators&zenid=f9b5a10dedaa137e853bf717433bb478
Keith black or United Pistons website. They have some great calculators to determine compression ratio and effective compression ratio that takes into
account cam duration. They also have some great articles on recommending target numbers. Read the articles and play around with some numbers.

You want to run regular gas, the edelbrocks are 76 cc combustion chambers, heart shaped combustion chambers can help as well as reducing deck height
(piston to head clearance), but that raises compression more so you need the engine apart so you can measure the piston to deck clearance. This takes
into account the head gasket thickness of usually .032" to .040" ish. on the airboat 489 I ran .020" piston to head clearance so yes the Pistons were
sticking out of the block. Most builders feel that anything over .035 will do nothing to control detonation.

[Espen Heitmann]

Finally got around to call Crane today, and after some discussion we decided on this grind, what do you think, yes still a roller camshaft and no need
for a softer distributer gear, the original is ok on Crane rollers.

Brute low end torque, smooth idle, daily usage, fuel economy, 1200-2000 cruise RPM, 8.0 to 9.25 compression ratio advised.Range 800-4600

Degrees Duration @ .050" Int/Exh.204/214
Advertised Degrees Duration Int/Exh.260/270
Degrees Lobe Separation 112
Open/Close @ .050" Cam Lift Int/Exh (5) 29/44 (10)
Gross Lift Int.486 Exh .512

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Chris Tyler]

Loffen wrote on Mon, 06 April 2015 19:17

> Finally got around to call Crane today, and after some discussion we decided on this grind, what do you think, yes still a roller camshaft and no
> need for a softer distributer gear, the original is ok on Crane rollers.
>
> Brute low end torque, smooth idle, daily usage, fuel economy, 1200-2000 cruise RPM, 8.0 to 9.25 compression ratio advised.Range 800-4600
>
> Degrees Duration @ .050" Int/Exh.204/214
> Advertised Degrees Duration Int/Exh.260/270
> Degrees Lobe Separation 112
> Open/Close @ .050" Cam Lift Int/Exh (5) 29/44 (10)
> Gross Lift Int.486 Exh .512

i think this one would be a better choice all around. The other cam would work, at the cost of 1-2 inches of idle vac and some low end. If you bump
the compression slightly, advance it a bit maybe andrun higher ratio gears it would really sing on the highway. But in reality, low end torque is what
you want.

If you get the chance, you can play with the specs on one of the 'Desktop Dyno' types of software that will show you how changing the specs changes
the torque curve and cylinder pressure

If money is not an object, I like rollers.

Last I heard, Jim B's Krytonite cam was only availible with the whole engine. That may have changed
--
76 Glenbrook

[Espen Heitmann]

I did just run a dyno on the cam

http://s1126.photobucket.com/user/Espen_Heitmann/media/1973%20Sequoia/Dyno0001_zpszurftzbv.jpg.html

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Robert Mueller]

Espen,

Here's links to some actual dyno runs on 455 Olds engines.

http://www.gmcmhphotos.com/photos/g6535-dyno-runs-neil-martin-27s-455.html

Here's a link to the dyno runs JimB and DrewK did when developing the Kryptonite cam:

http://www.gmccoop.com/koba_built_motors.htm

Scroll down and you'll find a bunch of dyno runs.

I compared the data and I reckon the simulated dyno run is optimistic.

Regards,
Rob M.

-----Original Message-----
From: Espen Heitmann

I did just run a dyno on the cam

http://s1126.photobucket.com/user/Espen_Heitmann/media/1973%20Sequoia/Dyno0001_zpszurftzbv.jpg.html

[Kerry Pinkerton]

Dang, that's pretty strong Loffen!
--
Kerry Pinkerton

North Alabama

77 Eleganza II, 403CI, Manny Brakes, 1 ton, tranny, lots of aluminum goodies.

77 Kingsley by Buskirk. Rear twins/dry bath, EFI Caddy.

Also a 76 Eleganza to be re-bodied as an Art Deco car hauler

[Espen Heitmann]

Yes maybe a little optimistic, with the alu heads, 9.5 Cr, headers..
We will see :)

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Espen Heitmann]

kerry pinkerton wrote on Wed, 08 April 2015 02:40

> Dang, that's pretty strong Loffen!

402 HP @ 4500 Rpm
576 Tq @ 2000 Rpm

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Les Burt]

Espen,
What are you going to do regarding your transmission?

IIRC, it was mentioned here a while back that Manny feels that the TH425 has trouble handling in excess of ~500ft/lb torque. The 6.5 diesel swap he is working on apparently requires substantial mods to the tranny to handle the extra torque. I believe it was also stated that the 6.5TD engine supplier was going to develop custom ECU programming to help keep low RPM torque within reasonable limits.

Something to keep in mind. More is not always better.

Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)

[Espen Heitmann]

Les, I bought Peter's transmission and final drive, it is getting a check up at Manny's now.

Yes this dyno is at the limit if it is correct, but I am that type of person that think if you use your head a little it will be just fine :)

[Robert Mueller]

Espen,

Along with the other dyno runs I just remembered this Dyno chart:
http://www.gmcmhphotos.com/photos/aa-miscellaneous-photos/p52884-dyno-run-vortec-81.html

As you can see it's for an 8.1 liter (495 cubic inch) Vortec, if you compare it to the simulated Olds 455 cubic inch dyno run it
also is not as powerful.

I think the operative words in the sentence below are "if it is correct."

Regards,
Rob M.


-----Original Message-----
From: Espen Heitmann

Les, I bought Peter's transmission and final drive, it is getting a check up at Manny's now.

Yes this dyno is at the limit if it is correct, but I am that type of person that think if you use your head a little it will be
just fine :)

[Bob de Kruyff]

Les Burt[1
> wrote on Tue, 07 April 2015 19:05]Espen,

A stock 6.5 is rated at 440 ft lb. Unless you have a different fuel program you won't remotely have trans problems.
--
Bob de Kruyff
78 Eleganza
Chandler, AZ

[Bob de Kruyff]

Loffen wrote on Tue, 07 April 2015 17:43

> I did just run a dyno on the cam

I think you are at least 100ft-lbs off on that curve.

--
Bob de Kruyff
78 Eleganza
Chandler, AZ

[Les Burt]

Bob,
It was reported here that Manny is building special TH425 units to handle the 6.5TD. If the diesels he will be using only produce 440 lbs torque, then the fact that he is beefing up the transmissions more than a typical Motorhome unit might be indicating that a stock transmission will have trouble with torque levels in that range or higher. His reasons for the special build are only speculation until you hear it from the horses mouth though.

As Espen indicated, driving with common sense will allow a stock TH425 to live behind a high-torque monster. Too many enthusiastic blasts up his local mountain roads and the transmission might eventually have something else to say.

Les Burt
Montreal
'75 Eleganza 26'
The EWIP (Eternal Work In Progress)
>

> A stock 6.5 is rated at 440 ft lb. Unless you have a different fuel program you won't remotely have trans problems.
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

[James Hupy]

The power on the AM General diesel can be turned up easily, and Manny
suspects that some of you knob twisters out there will do just that. He
wants the transmission to be as bulletproof as he can manage it. Just the
way he does things. He has a coach running with his conversion now
undergoing shakedowns. We are waiting to see the results. Hang in there.

Jim Hupy
Salem, Oregon
78 GMC ROYALE 403

[Espen Heitmann]

As said earlier so might this dyno be to optimistic, it is a PC dyno, take it for what it is !
Nothing can be said for sure before the engine is built and run in a real dyno..

And then I stumble over this article http://www.hotrod.com/how-to/engine/116-0010-455ci-engines/
There is a HP/Tq diagram in the slide show

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Robert Mueller]

Espen,

That's another meaningless dyno run as far as a GMC is concerned; note that it starts at 3500 rpm.

If you look at the Vortec 8.1 you will note that it puts out 410 ft lb at 1200 rpm, now THAT is IMPRESSIVE! BTW this is not the
"hottest" 8.1, Dave Lenzi has a model in his GMC that puts out even more HP and TQ. I drove it and it is UNBELIEVABLE!

I think I better explain why I'm busting your chops over this dyno run. When I lived in Hong Kong I built hot rod Harleys for guys,
one of them got his hands on a Harley PC dyno and commissioned me to build an engine just like one he spec'd out and ran on the PC
dyno. I did it and when I was done he took it to a REAL dyno and ran it. It did not make anywhere near the HP or TQ that the PC
program said it would. He accused me of not putting the parts he spec'd in the engine until I showed him the receipts for the parts
he told me to use. He then accused me of not putting the engine together correctly. I told him to bring the bike over and I would
disassemble and reassemble the engine in his presence which I did. When that was done he took it back to the dyno shop and it
produced the same results. He finally figured out that the PC dyno wasn't correct. DUH!

I came to the conclusion that the PC dyno programs are for boy racers that want to brag about how powerful their cars are and the
terrific dyno runs they produce.

As far as I'm concerned they're good for is making comparisons of different performance parts, not the bottom line!

Regards,
Rob M.

-----Original Message-----
From: Espen Heitmann

As said earlier so might this dyno be to optimistic, it is a PC dyno, take it for what it is !
Nothing can be said for sure before the engine is built and run in a real dyno..

And then I stumble over this article http://www.hotrod.com/how-to/engine/116-0010-455ci-engines/
There is a HP/Tq diagram in the slide show

[Kerry Pinkerton]

I don't think my 403 has ever seen 3500 rpm...certainly not since I've owned it. It lives in the 1500 to 3000 range 95% of the time it's moving.

--
Kerry Pinkerton

North Alabama

77 Eleganza II, 403CI, Manny Brakes, 1 ton, tranny, lots of aluminum goodies.

77 Kingsley by Buskirk. Rear twins/dry bath, EFI Caddy.

Also a 76 Eleganza to be re-bodied as an Art Deco car hauler

[George Beckman]

kerry pinkerton wrote on Wed, 08 April 2015 06:19

> I don't think my 403 has ever seen 3500 rpm...certainly not since I've owned it. It lives in the 1500 to 3000 range 95% of the time it's moving.

I rarely run my 455 over 3200. When my third gear was out I drove 150 miles to Manny's in 2nd. After a while you get used to 3800; it was the new
normal. I was making about 58 mph. It seemed quiet on the way home. Third gear is a good thing.
--
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George

[Bob de Kruyff]

""The power on the AM General diesel can be turned up easily, and Manny
suspects that some of you knob twisters out there will do just that. He
wants the transmission to be as bulletproof as he can manage it. Just the
way he does things. He has a coach running with his conversion now
undergoing shakedowns. We are waiting to see the results. Hang in there.
Jim Hupy
Salem, Oregon
78 GMC ROYALE 403

On Apr 7, 2015 8:46 PM, "Les Burt" wrote:

""

That's the nice thing about diesels--just pour more fuel to them. We limited them to 440 ft lb so we could cool them.

[Chris Tyler]

Yes, the computer dynos can be way off in terms of numbers.
However I have found the power curves peaks ect to be a pretty accurate prediction

Most of my engine dyno time was on the old school manually operated dynos with analog gauges. One person would run the dyno load and engine, another
would record data. Later we got smart and used a camcorder to review it.

One thing interesting was it was very hard to get a steady state reading below 3-3500, especially on a very torquey engine. THe computer assisted ones
like superflow can do sweep tests but still have a hard time on the low end

More recently learning about chassis dynos and electronic tuning with the turbo vette. Its a whole diffeent ball game.

Thing is. dynos vary in results. Sometimes operators tweak the results to make the numbers better. But very useful comparing different tuning and
parts if you compare apples to apples
--
76 Glenbrook

[Ronald Pottol]

​You just need to simulate a very funky wind tunnel kind of thing. I wonder
how many teraflops you would need for a reasonably accurate simulation? ​

Yes, I want a machine on my desk that can emulate a wind tunnel. But I bet
simulating a motor usefully is harder than an airplane.

On Wed, Apr 8, 2015 at 7:40 AM, Chris Tyler <dtyl...@tampabay.rr.com>
wrote:

--
Plato seems wrong to me today.

[Matt Colie]

Loffen wrote on Tue, 07 April 2015 19:43

> I did just run a dyno on the cam

Too bad you couldn't pull it down to the torque peak.

Matt

--
Matt & Mary Colie - Members GMCMI, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

[Espen Heitmann]

Rob I did talk to my engine builder and he said from his experience this dyno is about 10% off from what he does see on his test stand, of course
thinks like headers/vs manifolds will make a difference, but after looking at the cam specs and the rest of the engine he was pretty sure that it
would be over 500 in torque at very low rpm.

I do not think it is a useless dyno as it will give you an idea of what will work or not, but you should take it for what it is.

You can down load it from here for free :
http://www.colorado4x4.org/vbb/showthread.php?178647-Shhhhhs-Don-t-tell-anyone-Desktop-Dyno-Free-Download&hc_location=ufi

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Robert Mueller]

Espen,

I never said it was useless I noted that is a tool to compare different mods such as camshafts.

I did say that the dyno run from the Hot Rod network was meaningless because it started at 3500 rpm.

I just looked at Dyno1.dyn 455 Olds.dyn again and note that it starts at 2000 rpm. Can you get it to show what the engine does
starting at idle or 1000 rpm?

That data would relate to a GMC more when one considers this chart:

http://www.appliedgmc.com/level.itml/icOid/482

I want to know how much torque I'm going to get at lower rpms as that's what will accelerate the GMC up to the speeds in this chart.

Regards,
Rob M.

-----Original Message-----
From: Espen Heitmann

Rob I did talk to my engine builder and he said from his experience this dyno is about 10% off from what he does see on his test
stand, of course thinks like headers/vs manifolds will make a difference, but after looking at the cam specs and the rest of the
engine he was pretty sure that it would be over 500 in torque at very low rpm.

I do not think it is a useless dyno as it will give you an idea of what will work or not, but you should take it for what it is.

You can down load it from here for free :
http://www.colorado4x4.org/vbb/showthread.php?178647-Shhhhhs-Don-t-tell-anyone-Desktop-Dyno-Free-Download&hc_location=ufi

[Bob de Kruyff]

USAussie wrote on Wed, 08 April 2015 17:25

I'l be more blunt and say that the simulation is WAY optimistic. There is no way you will see that torque on an engine design this old. Recently GM
announced the new Corvette had something like 625 ft Lb of torque at idle. Your graphs look the same. You know better than that :)

--
Bob de Kruyff
78 Eleganza
Chandler, AZ

[Espen Heitmann]

But did you read the text in the article Rob, it did start at 3500 Rpm because the torque on the lower Rpm was above the range of the dyno :)

USAussie wrote on Thu, 09 April 2015 01:25
> Espen,

>
> I did say that the dyno run from the Hot Rod network was meaningless because it started at 3500 rpm.
>

> I want to know how much torque I'm going to get at lower rpms as that's what will accelerate the GMC up to the speeds in this chart.
>
>
> Regards,
> Rob M.
>
> -----Original Message-----
> From: Espen Heitmann
>
> Rob I did talk to my engine builder and he said from his experience this dyno is about 10% off from what he does see on his test
> stand, of course thinks like headers/vs manifolds will make a difference, but after looking at the cam specs and the rest of the
> engine he was pretty sure that it would be over 500 in torque at very low rpm.
>
> I do not think it is a useless dyno as it will give you an idea of what will work or not, but you should take it for what it is.
>
> You can down load it from here for free :
> http://www.colorado4x4.org/vbb/showthread.php?178647-Shhhhhs-Don-t-tell-anyone-Desktop-Dyno-Free-Download&hc_location=ufi
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________

[Chris Tyler]

[quote title=Loffen wrote on Thu, 09 April 2015 06:25]But did you read the text in the article Rob, it did start at 3500 Rpm because the torque on the

lower Rpm was above the range of the dyno :)

[
That's what I meant. If the dyno can only absorb 500 #/ft, you cannot load it enough to pull it down and get accurate readings.

Also interesting on the old school analog water brake dyno, you could check the calibration bu suspending a known weight off a given lever size,
calculate the torque and verify the reading.

BTW in our application, I say torque is king, especially down low.

What is useful on more sofisticated dynos is the brake specific fuel consumtion, which gives a good indication of efficiency.

Interesting that we found under full power turbos and especially superchargers were less efficiant [owing to parasitic load, backpressure or probably
a richer fuel mixture] but at part throttle [steady state]it improved

My corvette makes 556 RW #/ft of torque at 3000, 10# boost on pump gas, and gets 30-33 mpg on the highway.

I don't see any reason a near stock spec olds 455 cannot make 500 #/ft. I got 520 out of a 406 chevy with 9.7 and basicly the performer RPM
cam/manifold, injected.

--
76 Glenbrook

[Carl Stouffer]

Loffen wrote on Wed, 08 April 2015 00:48

> As said earlier so might this dyno be to optimistic, it is a PC dyno, take it for what it is !
> Nothing can be said for sure before the engine is built and run in a real dyno..
>
> And then I stumble over this article http://www.hotrod.com/how-to/engine/116-0010-455ci-engines/
> There is a HP/Tq diagram in the slide show

Very interesting article. It begs the question of whether or not those Edelbrock aluminum heads would benefit us in our application. We don't
generally need the higher flow characteristics the hot rod guys are after, but it seems to me that we could run a little more compression, given the
thermal characteristics of aluminum heads, That, combined with a low end cam would seem to give us more torque and horsepower without burning it up.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.

[Neil Martin]

It is not just what parts you put into the engine, it is how it is tuned.

I invested some $ with a top dyno tuner and the hp and torque gains were astounding. (Unfortunately he is now out of business - health reasons)

Rob posted those dyno sheets for me some years ago.

http://www.gmcmhphotos.com/photos/dyno-runs-neil-martin-27s-455/p52841-pg-1.html

Take a good look at how much we picked up from the first run to the last. I think the total cost was about $800.

This was just timing, jetting and reshaping the metering rods.


--
Neil
76 Eleganza
Los Angeles

[James Hupy]

I learned a very expensive and long lasting lesson from my racing
experience. That is, "BEFORE YOU CAN MAKE IT FAST, YOU HAVE TO MAKE IT
LAST". Pretty simple concept really, but damn hard to achieve. Listen to
Jim Bounds when he talks about Drew Koba engines. Listen to Dick Paterson
when he talks about torque monster Oldsmobiles. Yes, it can be done. No, it
won't be cheap. If you put more air fuel in a cylinder and ignite it, you
are going to put more pressure on top of the piston and everything from
there to the tires. Exceed the strength of the materials involved, and bad,
expensive, stuff happens. I am living proof of that statement, and I still
have some of the broken parts left to remind me to "Don't go there". But,
hey, it's your money, spend it like the government does. I would rather
spend it on fuel and rv park fees.
Jim Hupy
Salem, Or
78 GMC ROYALE 403

[Robert Mueller]

Espen,

Nope, I didn't read the article because the dyno run wasn't relevant to a GMC as it started at 3500 rpm.

Please don't get me wrong, you going to spend a lot of money to build an engine and I hope it meets your expectations.

Regards,
Rob M.

-----Original Message-----
From: Espen Heitmann

But did you read the text in the article Rob, it did start at 3500 Rpm because the torque on the lower Rpm was above the range of
the dyno :)

[Espen Heitmann]

This old tread.. well I take it up again, things are going slow here but going :) the USD has gained over 50% in value compared to the NOK the last
year so buying parts from the US is a pain for my wallet.
Anyways, I bought a rockwell intake, it is on it's way over the pond but I do wonder if anyone know if it will clear roller lifters ? the stock intake
will not but it looks like the Rockwell has better clearance.

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:

http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

[Adolph Santorine]

I'm running a stock manifold with a roller cam.

To make it work, you have to grind the top of the lifters so they clear.

It seems to work just fine.

Dolph Santorine

DE N8JPC

Wheeling, West Virginia

1977 ex-Palm Beach TZE167V100820
1-ton, Sullybuilt Bags, Reaction Arms, 3.70 LSD, Manny Transmission, EV-6010,

[Espen Heitmann]

But then you have the bar towards the cylinders right ?
Do you remember what brand of lifters you have and what camshaft ?

Dolph Santorine wrote on Sun, 27 December 2015 00:43

[Jim Kanomata]

One advantage of a roller cam is the ability of opening and closing the
intake and exhaust at a rapid rate to reach full open duration longer and
still shut off in that duration.
There are two lifters one need to trim to clear the intake manifold
runners. Roller lifters are taller.
Make sure that the cam gear is compatible with the distributor gear.
Bronze and phenolic gears are good for drag racing and will not last for
our use.

On Sat, Dec 26, 2015 at 3:43 PM, Adolph Santorine <ado...@santorine.org>
wrote:

--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502

[Jim Kanomata]

There is only one way the bars will clear.

[Espen Heitmann]

And those two lifters has to be cut with the rockwell intake to Jim ?

I will be using a roller cam from Crane so the original distributor gear is fine, no need to change it (one of the reasons why I want a cam from
Crane)

[Jim Kanomata]

Can't remember as it was about 5 years ago.

--

Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502

[lenze middelberg]

With all this talk of hp, torgue and steering. I hope I will get the change to drive a orher gmc. Just to feel differnces
--
Appie
eleganza 76 "Olga" ( pictures at http://www.gmcmhphotos.com/photos/g6489-olga.html
Fulltiming in Europe since july 1 2014
Denmark

[Espen Heitmann]

We will meet Appie, just give it a couple of years ;)

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

[lenze middelberg]

Maybe at the firsth european gmc meet

--
Appie
eleganza 76 "Olga" ( pictures at http://www.gmcmhphotos.com/photos/g6489-olga.html
Fulltiming in Europe since july 1 2014
Denmark

[Espen Heitmann]

Yes :) And I am pretty sure that you will get a chance to try out a coach or two there :)

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway

[Peer Oliver Schmidt GMC]

Am 27.12.2015 um 12:33 schrieb Espen Heitmann:
> Yes :) And I am pretty sure that you will get a chance to try out a coach or two there :)

As I am in the middle between Netherlands and Norway, you all will just
meet in my parking lot. Appie knows the way already... :D

And in a year or 10 I'll have my GMC over in Europe as well.

--
Best regards

Peer Oliver Schmidt
PGP Key ID: 0x83E1C2EA

'76a Eleganza II, VA

[Jarkko Lampinen]

appie wrote on Sun, 27 December 2015 13:25

> Maybe at the firsth european gmc meet

I´m in, when and where ??

Jake
--
Jarkko Lampinen
`77 Palm Beach TZE167V100508
Finland Europe

[Espen Heitmann]

Uhm.. just let me get the frame under the body first ;)

I would guess Denmark or Germany..

And Jake please join this facebook group https://www.facebook.com/groups/570762296399629/

--
1973 26'-3 # 1460 Parrot green Seqouia Known as the Big Mean Green Machine,
And just sold my 1973 26'-2 # 581 White Canyon lands under the name Dobbelt trøbbel
in Norway