Saab Bites the dust
Cliff
�It was designed to provide transportation under miserable weather
conditions.�
I worked with a ComputerVision programmer that had one.
--
Cliff
Bill McKee
"Cliff" <Clhuprich...@aoltmovetheperiodc.om> wrote in message
news:pp7pi5h3vtb0j4uoe...@4ax.com...
You know why it was called Saab? Because that is what you did as you went
to the bank to pay for repairs.
Curly Surmudgeon
Like the alternator and water pump being on the same belt-driven
driveshaft so water pump seal leakage flowed directly into the
alternator. Independent front suspension but solid axle in the rear.
Good intentions but never a very good design. Except for the V4 engine
when allied with Ford. Wonder if their fighter jets were any better?
--
Regards, Curly
------------------------------------------------------------------------------
Vote Republican, Suffering Builds Character
------------------------------------------------------------------------------
HoLmEs
news:pp7pi5h3vtb0j4uoe...@4ax.com:
Was that at GM Hughes Electonics.......?
cncmillgil
Ya ya das is svedish you know along wtih de wolwo.
~g~
Cliff
No, never worked there. Just for other GM groups & divisions,
among other firms.
Here: http://www.gdbiw.com/
Before GD bought them. They used & supported quite
a bit of their own custom software so needed experts &
applications engineers to write & maintain it (plus
many CV features were developed for them in the first
place).
The guy from CV had been RIFed from CV IIRC and was also there
on contract.
Last I heard they had reused/recycled much of my code for
added projects <g>.
Oldest shipyard in the US.
IIRC The JOHN S. McCAIN was commissioned while I was there
& the president attended.
http://www.youtube.com/watch?v=sPs3TwrRY2g
Some ship, anyway.
--
Cliff
oldjag
wrote:
I had a '68 Saab 96 with the V4. Put about 150K miles on it, and it
was used when I got it. Great car for jumping hump back bridges etc.,
very difficult to bottom out, and the suspension was almost impossible
to break. Had a 390 cubic inch big block Ford V8 to haul to the
machine shop for a rebuild and no pickup truck at the time. It just
fit in the Saabs trunk. The guys at the machine shop jaws dropped
when I opened the trunk to unload it. Great car for taking to the ski
slope, I had a neat trick for getting out of a snowy or icy parking
slot...turn wheel all the way to the left stop, pull the hand brake
on, put in reverse and dump the clutch...the result was amazing..the
car would rotate about it's centerline, and if you timed it right you
could just shift into first and just drive off in the opposite
direction. With studded snow tires it was better than some four wheel
drives of the time, with like 65% or better of the weight on the front
wheels, a flat bottom, and a lot of ground clearance.
Ed Huntress
"oldjag" <msmit...@comcast.net> wrote in message
news:650763fa-7561-4a99...@k9g2000vbl.googlegroups.com...
On Dec 19, 4:43 am, Cliff <Clhuprichguessw...@aoltmovetheperiodc.om>
wrote:
> http://www.nytimes.com/2009/12/19/business/19brand.html
> �It was designed to provide transportation under miserable weather
> conditions.�
>
> I worked with a ComputerVision programmer that had one.
> --
> Cliff
>I had a '68 Saab 96 with the V4. Put about 150K miles on it, and it
>was used when I got it. Great car for jumping hump back bridges etc.,
>very difficult to bottom out, and the suspension was almost impossible
>to break.
Remember those great winter rally battles in the '60s, between Erik Carlsson
(Saab) and Paddy Hopkirk (Mini Cooper)? They were spectacular. Saabs were a
real premium small car in those days.
One of my buddies in high school had one of the 3-cyl., 2-stroke originals.
Very clever cars. But the freewheeling transmission would scare the piss out
of you if you didn't know it was there. <g>
--
Ed Huntress
Joseph Gwinn
"Ed Huntress" <hunt...@optonline.net> wrote:
I spent a year in Sweden in the mid 1970s, and I recall the 2-stroke
Saabs. The farmers loved them, as they were dead easy to repair. As
the story goes, the engine had only seven moving parts. I don't know if
this is exactly true, but still the engines were very simple. And no
electronics of course.
Joe Gwinn
Curly Surmudgeon
Saab had a 3-cyl 2-stroke? I remember DKW(or some German car) had one
but not Saab... Gas tank was in the firewall between the engine and
dashboard. Pour in a quart of oil and 10 gallons of gasoline.
Ed Huntress
"Joseph Gwinn" <joeg...@comcast.net> wrote in message
news:joegwinn-D63977...@news.giganews.com...
I think that was the case: three pistons, three con rods, and a crankshaft.
I think it had reed valves. 850 cc, but you could do some tricks to it and
make it pretty hot -- maybe it was squaring the ports.
I raced against one in SCCA, back around 1970. It was very credible.
--
Ed Huntress
Lewis Hartswick
> Remember those great winter rally battles in the '60s, between Erik Carlsson
> (Saab) and Paddy Hopkirk (Mini Cooper)? They were spectacular. Saabs were a
> real premium small car in those days.
>
> One of my buddies in high school had one of the 3-cyl., 2-stroke originals.
> Very clever cars. But the freewheeling transmission would scare the piss out
> of you if you didn't know it was there. <g>
>
was very good vehicle. Those were the ones with the oil
tank and metered total loss lub. so didn't have to mix the
oil in the gas. Did have Weird spark plugs they called them
surface gap, ie. the center electrode was at the same surface
as the insulator and outer shell.
...lew...
Ed Huntress
"Curly Surmudgeon" <CurlySu...@live.com> wrote in message
news:hgoson$dt0$1...@news.eternal-september.org...
Yup, that's how they started. The two-stroke was better lubricated starting
in cold weather. Knowledge of this is an indicator of one's age. <g>
--
Ed Huntress
Ed Huntress
"Lewis Hartswick" <lhart...@earthlink.net> wrote in message
news:uuGdneeF2ID3YbLW...@earthlink.com...
Yes, they were used in outboards, too. The design resisted fouling much
better in two-strokes, before electronic ignition.
--
Ed Huntress
Diogenes
I drove 2-stroke Saabs around New England for several years,
absolutely great little cars. The handling and aerodynamics were
remarkable and they went like merry hell in the snow.
That 2-stroke engine was a neat little piece of engineering. It was so
light that I could actually pull it out of the car single-handed
without an engine hoist, set it on the ground, work on it and then
pick it up and put it right back in.
On the early 2-strokes, Saab actually gave a complete parts & labor
>lifetime< warranty to the original owner! The electrics were Bosch
(no problem there) but the brakes were British Lockheed, the only
system in the damn car that ever gave me trouble. In Europe,
incidentally, they were called "ring-a-dings" due to the unusual sound
they made.
I later owned a couple of V-4's, which were also excellent cars, but
they weren't nearly as much fun as those old strokers.
----
Diogenes
The wars are long, the peace is frail
The madmen come again . . . .
Ed Huntress
"Diogenes" <cdh...@hotmail.com> wrote in message
news:vd80j5167j4v49b7b...@4ax.com...
Since there are several former owners of V-4s here, maybe someone can answer
an old question I never had answered: Did those suckers vibrate badly? Their
inherent balance was lousy, but good engineering can cope with that. I never
knew what they were like.
--
Ed Huntress
Curly Surmudgeon
<hunt...@optonline.net> wrote:
Why would you think a V4 is imbalanced? The number of cylinders or
degree of angle between banks is irrelevant to balance. Witness the
single cylinder engine, 2, 4, 6, 8, 10, 12 & 16 cylinder V engines or the
3 & 5 cylinder in-lines. Then there are the 2, 4, 6, 8, 10 & 12 cylinder
pancake engines... All are balanced or they'd shake themselves to death.
Never owned a Saab but lusted after the Sonett II V4.
Ed Huntress
Because I read the MIT Sloan Lab books on engine design and balance when I
was an engineering student. <g>
Even-firing 4-stroke inline fours have primary balance (fore-and-aft rocking
balance) but no secondary balance (secondary is up-and-down balance that
fours don't have because the pairs of pistons are accelerating and
decelerating at different rates). V4s have no primary balance. The German
Ford Taunus V4, which is the engine used by Saab, had a counterbalance shaft
that was supposed to impose an approximate balance on the engine. What I
want to know is if it worked.
> The number of cylinders or
> degree of angle between banks is irrelevant to balance. Witness the
> single cylinder engine, 2, 4, 6, 8, 10, 12 & 16 cylinder V engines or the
> 3 & 5 cylinder in-lines. Then there are the 2, 4, 6, 8, 10 & 12 cylinder
> pancake engines... All are balanced or they'd shake themselves to death.
Nope. Inline fours have primary balance. Inline sixes have both primary and
secondary balance. Inline threes and fives, when four-strokes, can be
approximately balanced by a couple of different means. If they're
two-strokes, balance is much easier because each piston is doing the same
thing each time it goes up or down.
V6s also lack primary balance. 90-degree V6s are *really* unbalanced. GM
used an offset in the adjacent pairs of crank journals, called the
"split-pin" design, to approximate the balance of a 120-degree or 60-degree
in their 90-degree Buick V6, which started as a totally unbalanced truck
engine but was migrated over to small cars in the early '60s. At first, they
didn't have the split-pin cranks, and they really rocked and rolled.
With greater numbers of cylinders, some designs have primary, secondary, and
tertiary balance. IIRC, tertiary balance requires pistons at equal distances
from the ends of the engine to not only be going the same way, but also to
be firing at the same time. I think. It's been a long time since I read that
stuff.
>
> Never owned a Saab but lusted after the Sonett II V4.
>
> --
> Regards, Curly
--
Ed Huntress
Ned Simmons
<hunt...@optonline.net> wrote:
>
>"Diogenes" <cdh...@hotmail.com> wrote in message
>news:vd80j5167j4v49b7b...@4ax.com...
>> That 2-stroke engine was a neat little piece of engineering. It was so
>> light that I could actually pull it out of the car single-handed
>> without an engine hoist, set it on the ground, work on it and then
>> pick it up and put it right back in.
>>
>> On the early 2-strokes, Saab actually gave a complete parts & labor
>>>lifetime< warranty to the original owner! The electrics were Bosch
>> (no problem there) but the brakes were British Lockheed, the only
>> system in the damn car that ever gave me trouble. In Europe,
>> incidentally, they were called "ring-a-dings" due to the unusual sound
>> they made.
>>
>> I later owned a couple of V-4's, which were also excellent cars, but
>> they weren't nearly as much fun as those old strokers.
>>
>> ----
>> Diogenes
>
>Since there are several former owners of V-4s here, maybe someone can answer
>an old question I never had answered: Did those suckers vibrate badly? Their
>inherent balance was lousy, but good engineering can cope with that. I never
>knew what they were like.
My wife owned a Saab 96 when I met her. It must have been a 1968 or
so. It remember it as a comfortable car, though my point of reference
was my '69 Dodge 3/4T 4WD. I never did get the hang of the overunning
clutch, and didn't spend a lot of time trying because Doreen loved
that car and my ineptitude put a strain on the relationship. I let her
drive.
My uncle owned DKWs back in the early '60s and I had a friend in
college who had a Saab 93 2-stroke. Marshall was a big boy and he also
lifted the engine out to work on it.
I always chalked up the common ring-a-ding sound to the fact the DKW
and Saab were both 2-strokes, but apparently there's more to it than
that. Wikipedia says the Saab was based on the DKW design.
http://en.wikipedia.org/wiki/Saab_two-stroke
--
Ned Simmons
F. George McDuffee
<hunt...@optonline.net> wrote:
>>> Since there are several former owners of V-4s here, maybe someone can
>>> answer an old question I never had answered: Did those suckers vibrate
>>> badly? Their inherent balance was lousy, but good engineering can cope
>>> with that. I never knew what they were like.
>>
>> Why would you think a V4 is imbalanced?
>
>Because I read the MIT Sloan Lab books on engine design and balance when I
>was an engineering student. <g>
========
You will probably enjoy the following sites:
http://www.saabnet.com/tsn/models/1967/pr1.html
http://en.wikipedia.org/wiki/Ford_Taunus_V4_engine
http://en.wikipedia.org/wiki/Saab_96
http://www.carthrottle.com/obsolete-engines-101-the-mythical-v4/
Unka George (George McDuffee)
..............................
The past is a foreign country;
they do things differently there.
L. P. Hartley (1895-1972), British author.
The Go-Between, Prologue (1953).
Ed Huntress
"Ned Simmons" <ne...@nedsim.com> wrote in message
news:9ue0j55m9hk1nuvbj...@4ax.com...
Interesting, Ned. Thanks.
--
Ed Huntress
Curly Surmudgeon
<hunt...@optonline.net> wrote:
Nope, *all* auto engines that we're speaking of have a large degree of
primary balance, the fundamental harmonic, which is mainly a function of
counterweights (or opposing pistons in a flat engine) on the crankshaft
equal and their opposite piston/rod/pin/ring mass. Yes, there is some
small 2nd harmonic, Y and Z axis vibration (pitch, yaw and roll too) but
those are well contained with flywheels and harmonic balancers.
> Inline sixes have both primary and secondary balance.
Depends upon your threshold for no reciprocating engine has perfect
balance with the piston mass moving in one dimension and the crank
counterweights in two dimensions.
> Inline threes and fives, when four-strokes, can
> be approximately balanced by a couple of different means. If they're
> two-strokes, balance is much easier because each piston is doing the
> same thing each time it goes up or down.
True but those forces are imparted to the opposite piston, flywheel and
motor mounts. Pitch, yaw and roll (which you mention below) are
relatively trivial in some axis' with a V4 (crankshaft 2.5 piston centers
long), a V6 (crankshaft 3.5 piston centers long) but they do have a Y-
axis thump, or an in-line 4. Secondary balance isn't even a serious
issue on long engines as mfrs add main journals as necessary. The
Rambler straight-6 had 7 main bearings.
> V6s also lack primary balance. 90-degree V6s are *really* unbalanced. GM
> used an offset in the adjacent pairs of crank journals, called the
> "split-pin" design, to approximate the balance of a 120-degree or
> 60-degree in their 90-degree Buick V6, which started as a totally
> unbalanced truck engine but was migrated over to small cars in the early
> '60s. At first, they didn't have the split-pin cranks, and they really
> rocked and rolled.
Which is why few manufacturers made V6's. The best I've seen was the PRV
used by Volvo, Pugeot, Renault, DeLorean and a few others. The GMC V6 of
the 60's was a brute force monster (90 degree) and not related to the
modern aluminum V6 of late.
> With greater numbers of cylinders, some designs have primary, secondary,
> and tertiary balance. IIRC, tertiary balance requires pistons at equal
> distances from the ends of the engine to not only be going the same way,
> but also to be firing at the same time. I think. It's been a long time
> since I read that stuff.
Which is actually pitch, roll and yaw, a 3-dimensional vibration.
>> Never owned a Saab but lusted after the Sonett II V4.
--
Regards, Curly
Ed Huntress
"F. George McDuffee" <gmcd...@mcduffee-associates.us> wrote in message
news:u4f0j5hggq3osokll...@4ax.com...
> On Mon, 21 Dec 2009 22:08:17 -0500, "Ed Huntress"
> <hunt...@optonline.net> wrote:
>
>>>> Since there are several former owners of V-4s here, maybe someone can
>>>> answer an old question I never had answered: Did those suckers vibrate
>>>> badly? Their inherent balance was lousy, but good engineering can cope
>>>> with that. I never knew what they were like.
>>>
>>> Why would you think a V4 is imbalanced?
>>
>>Because I read the MIT Sloan Lab books on engine design and balance when I
>>was an engineering student. <g>
> ========
> You will probably enjoy the following sites:
> http://www.saabnet.com/tsn/models/1967/pr1.html
> http://en.wikipedia.org/wiki/Ford_Taunus_V4_engine
> http://en.wikipedia.org/wiki/Saab_96
> http://www.carthrottle.com/obsolete-engines-101-the-mythical-v4/
Good stuff, George. I remember those Lancias. A guy in my club had three or
four of them. Very unusual.
--
Ed Huntress
Ed Huntress
I don't know where you're going with this, Curly, but I'm getting that
information from (my memory of) Taylor's _The Internal Combustion Engine in
Theory and Practice_, published decades ago by MIT Press, and Thompson's
_Fundamentals of Automotive Engine Balance_, published in the late '70s.
Those books describe it as I have here, assuming my memory is correct, and I
have never seen a book on engine design that contradicts it.
Crankshaft balancing cannot compensate for the inherent imbalance of a 2 or
3 cylinder four-stroke engine. That's why those engines (and single cylinder
engines, and V4s) often are built with counterbalance shafts, which
typically run at twice engine speed.
Anyway, I'm not going to dig out the old books for this discussion, so
believe what you will.
--
Ed Huntress
F. George McDuffee
<hunt...@optonline.net> wrote:
>
>"F. George McDuffee" <gmcd...@mcduffee-associates.us> wrote in message
>news:u4f0j5hggq3osokll...@4ax.com...
>> On Mon, 21 Dec 2009 22:08:17 -0500, "Ed Huntress"
>> <hunt...@optonline.net> wrote:
>>
>>>>> Since there are several former owners of V-4s here, maybe someone can
>>>>> answer an old question I never had answered: Did those suckers vibrate
>>>>> badly? Their inherent balance was lousy, but good engineering can cope
>>>>> with that. I never knew what they were like.
>>>>
>>>> Why would you think a V4 is imbalanced?
>>>
>>>Because I read the MIT Sloan Lab books on engine design and balance when I
>>>was an engineering student. <g>
>> ========
>> You will probably enjoy the following sites:
>> http://www.saabnet.com/tsn/models/1967/pr1.html
>> http://en.wikipedia.org/wiki/Ford_Taunus_V4_engine
>> http://en.wikipedia.org/wiki/Saab_96
>> http://www.carthrottle.com/obsolete-engines-101-the-mythical-v4/
>
>Good stuff, George. I remember those Lancias. A guy in my club had three or
>four of them. Very unusual.
========
FWIW --
While GM has owned SAAB for about 20 years, it was only during
the last ten years of ownership that GM "converted" SAAB from a
car manufacturing company with extensive aerospace engineering
and design capability into a car assembly operation, after they
took complete control c.2000.
It now appears that most if not all of the SAAB
design/engineering capability has been dissipated. Operationally
they now assemble custom Opel Vectras and Saturn Auras with the
ignition lock relocated from the steering column to between the
front seats.
The major SAAB sales barrier appears to be that when potential
buyers do their due diligence they discover just how hollowed out
SAAB has become, and what they would be buying is a "bitsa" kit
car assembly operation, not a car
design/engineering/manufacturing operation, with GM the sole
source of the most critical components. Same story as Saturn and
Pensky.
I have never owned a 93 or 95, but owned and drove a 1974 99 for
280k miles. Not completely trouble free, but a good honest car,
and I wish I could buy another.
Ed Huntress
Yeah. The push to consolidate platforms and engines,which has been going on
for decades but which really took off with Ford/Mazda, Renault/Nissan,
GM/Opel/Saab, etc. a little over a decade ago, will result in a world with
about a dozen different cars, say the people who follow it closely.
Economy of scale is really in the driver's seat. See "New Trade Theory."
--
Ed Huntress
Cliff
My old '62 220SB was great in deep snow.
The unibody "rails" coming back from the engine area
to under the passenger compartment acted a bit like rails/skis
& it would about float over deeper snow.
Rust was a problem ...
--
Cliff
Cliff
<gmcd...@mcduffee-associates.us> wrote:
>It now appears that most if not all of the SAAB
>design/engineering capability has been dissipated.
IIRC They were implementing Unigraphics in
the '96 timeframe.
I had been asked to go & help on contract but had
already committed to another job.
http://www.google.com/search?hl=en&source=hp&ie=ISO-8859-1&q=SAAB+unigraphics&btnG=Google+Search
--
Cliff
Cliff
wrote:
> That's why those engines (and single cylinder
>engines, and V4s) often are built with counterbalance shafts, which
>typically run at twice engine speed.
Crank makes one rev per full stroke cycle IIRC,
even for 2 full stroke cycle (AKA 4 stroke) engines.
--
Cliff
BottleBob
=======================================================
http://en.wikipedia.org/wiki/Engine_balance
There are two main control mechanisms for secondary balance � matching
the phasing of pistons along the crank, so that their second order
contributions cancel, and the use of Lanchester balance shafts, which
run at twice engine speed, and so can provide a counteracting force.
Engines with particular balance advantages include:
Straight-6
Flat-4 with two geared crankshafts
Flat-6
Flat-12
V12
Engines with characteristic problems include:
Flat-4 boxer and straight-4 using a single crankshaft have no better
kinetic energy balance than a single, and require a relatively large
flywheel.
Crossplane V8, which requires a very heavily weighted crankshaft, and
has unbalanced firing between the cylinder banks (producing the
distinctive and much-loved V8 "burble").
Flatplane (180� offset crankshaft) V8.
=======================================================
--
BottleBob
http://home.earthlink.net/~bottlbob
cavelamb
And then there are the three cylinder (Geo, etc). :(
Steve W.
>
>
> And then there are the three cylinder (Geo, etc). :(
>
What about the 5 cylinder? I think the only numbers I haven't heard of
are 7 and 9 cylinder. Have seen an 11 cylinder that was used on a fire
engine. It was a 12 cylinder with one cylinder adapted to an air
compressor to pressurize the tank.
--
Steve W.
cavelamb
BottleBob
>
> And then there are the three cylinder (Geo, etc). :(
>
CL:
Geo Metro 3 cylinder inline engines are one of those engines that use
a counter balance shaft for balancing.
==============================================================
http://en.wikipedia.org/wiki/Straight-three_engine
Most inline-three engines employ a crank angle of 120�, and are thus
rotationally balanced; however, since the three cylinders are offset
from each other, the firing of the end cylinders induces a rocking
motion from end to end, since there is no opposing cylinder moving in
the opposite direction as in a rotationally balanced straight-six. The
use of a balance shaft in an antiphase to that vibration produces a
smoothly running engine.
==============================================================
--
BottleBob
http://home.earthlink.net/~bottlbob
Jim Wilkins
> ...
> http://en.wikipedia.org/wiki/Engine_balance
...
> BottleBobhttp://home.earthlink.net/~bottlbob
I found and tried to understand that article early this morning but
had to stop to get ready for a dental appointment. That's what my
writing looks like BEFORE editing for clarity. I can't visualize 3D
motion and explain it in words at the same time.
jsw
BottleBob
> On Dec 22, 11:24 am, BottleBob <bottl...@earthlink.net> wrote:
>> ...
>> http://en.wikipedia.org/wiki/Engine_balance
> I found and tried to understand that article early this morning but
> had to stop to get ready for a dental appointment. That's what my
> writing looks like BEFORE editing for clarity. I can't visualize 3D
> motion and explain it in words at the same time.
Mr. Wilkins:
If you think THAT one's bad in the area of clarity. Try this one:
LOL
--
BottleBob
http://home.earthlink.net/~bottlbob
Ed Huntress
"Jim Wilkins" <kb1...@gmail.com> wrote in message
news:bd7ca839-4bb6-47b6...@c34g2000yqn.googlegroups.com...
I didn't read the article Bob pointed to but maybe I can point out a couple
of things that will give some perspective.
There are two basic approaches to engine balance. One is the traditional
one, used by manufacturers before sometime in the '70s, which is known as
"inherent balance" or the "lumped-mass" approach. That's what I've been
talking about and that's what Ford used to design the Saab engine we're
discussing. SAE has a paper on its Website, written by Ford engineers in
1967, that describes how they designed that engine. It's $12 for members and
$15 for non-members, and I don't have a free source for those things
anymore, so I'm not buying. <g>
The other, and this may be what Curly is getting at, is sometimes called
"total factor" analysis, or something like that. When Audi and MB designed
their 5-cyl. engines, that's what they used.
The lumped-mass approach separates the balance you can achieve by the
rotating mass of the crankshaft counterweights from the reciprocating masses
you're trying to balance, and accepts the fact that you can only achieve
partial balance with the crank weights, because they're dynamically very
different from the up-and-down masses that need the major balancing. Con
rods are sort of halfway between, and they complicate the picture.
When you do a CAE analysis of all the dynamic masses, you can look at
everything, and use computer power to analyze the best-case balance you can
achieve. You also can run through iterations and tweak the basic design to
get better balance, in the smallest increments you want. When all goes
according to plan, you can take an engine that's inherently unbalanced, like
a 5-cylinder four-stroke, and wind up with very low vibration overall. I
wouldn't even try to separate primary and secondary balances in that case;
maybe they do, but I think all of the vibration modes just go into a pot.
The last thing I ever read about engine balance was an analysis of that
5-cyl. Audi engine, which showed up in the Audi 5000 and the 1983 VW Quantum
in the US, which I used to have as a company car. It was delightful -- the
car, not the analysis. <g> That was when I sort of hung up my boots. It was
getting too complicated.
Maybe this helps or maybe it makes it worse. If it's the latter, sorry. d8-)
--
Ed Huntress
Curly Surmudgeon
<hunt...@optonline.net> wrote:
> I don't know where you're going with this, Curly, but I'm getting that
> information from (my memory of) Taylor's _The Internal Combustion Engine
> in Theory and Practice_, published decades ago by MIT Press, and
> Thompson's _Fundamentals of Automotive Engine Balance_, published in the
> late '70s. Those books describe it as I have here, assuming my memory is
> correct, and I have never seen a book on engine design that contradicts
> it.
I'm not arguing for argument's sake. Vibration analysis is a topic near
and dear to my heart, I have two patents in the industry for dynamic
balancers.
I've approached the topic not from the mechanical engineering standpoint
but from the view of an Electro-mechanical Engineer with a strong physics
and software background also ex-auto/motorcycle racer.
Most of my mechanical knowledge was picked up as needed, not in school,
so you may have more book learning on engines but I suspect my experience
in vibrational analysis is stronger. We come at the problem from
different perspectives.
I have little respect for reed-valve and 2-cycle engines. I have looked
balance and vibration of 4, 6 and 8 cylinder engines in a number of
configurations but from the practical, not theoretical side. Now you've
got me madly studying the theoretical.
"Imbalance" has many meanings. My original question was from the
practical, the Saab/Taunus V4 was as "balanced" as production tolerances
permit. Your question pertained to design, not manufacturing. That was
not clear at first.
I interpreted your inquiry of "balance" as counterweight offset. Looking
at the theoretical it's much more complex than primary or secondary
"balance" in the theoretical sense. As Bottlebob's link shows, it is 3-
dimensional vibrational vectors, harmonics plus pitch, yaw and roll too
however that article doesn't even touch the valve train vibrational
components...
Fun topic.
Curly Surmudgeon
wrote:
Great link, which part is unclear?
Curly Surmudgeon
wrote:
> cavelamb wrote:
>
>
>> And then there are the three cylinder (Geo, etc). :(
>>
>>
> CL:
>
> Geo Metro 3 cylinder inline engines are one of those engines that
use
> a counter balance shaft for balancing.
>
> ==============================================================
>
> http://en.wikipedia.org/wiki/Straight-three_engine
>
> Most inline-three engines employ a crank angle of 120°, and are
thus
> rotationally balanced; however, since the three cylinders are offset
> from each other, the firing of the end cylinders induces a rocking
> motion from end to end, since there is no opposing cylinder moving in
> the opposite direction as in a rotationally balanced straight-six. The
> use of a balance shaft in an antiphase to that vibration produces a
> smoothly running engine.
> ==============================================================
Heh, "that depends upon what the definition of "is" is."
BottleBob
> On Tue, 22 Dec 2009 09:40:51 -0800, BottleBob <bott...@earthlink.net>
> wrote:
>
>> cavelamb wrote:
>>
>>
>>> And then there are the three cylinder (Geo, etc). :(
>>>
>>>
>> CL:
>>
>> Geo Metro 3 cylinder inline engines are one of those engines that
> use
>> a counter balance shaft for balancing.
>>
>> ==============================================================
>>
>> http://en.wikipedia.org/wiki/Straight-three_engine
>>
>> Most inline-three engines employ a crank angle of 120°, and are
> thus
>> rotationally balanced; however, since the three cylinders are offset
>> from each other, the firing of the end cylinders induces a rocking
>> motion from end to end, since there is no opposing cylinder moving in
>> the opposite direction as in a rotationally balanced straight-six. The
>> use of a balance shaft in an antiphase to that vibration produces a
>> smoothly running engine.
>> ==============================================================
>
>
> Heh, "that depends upon what the definition of "is" is."
CS:
The Geo Metro engine is an inline 3 cylinder design with a 120 degree
crank angle. It uses an antiphase balance shaft (In ADDITION to the
crankshaft), to produce a smooth running engine.
Here are some other engines whose designs have balance problems severe
enough to need an extra counter balance shaft, sometimes two.
============================================================
http://en.wikipedia.org/wiki/Balance_shaft
Production implementations
Other manufacturers producing engines with one or two balance shafts
include(d):
Alfa Romeo 2.0L four-cylinder, as fitted to the Alfa Romeo 156
BMW K75 motorcycle
Chrysler K engine
Chrysler 2.4 L and 2.5 L Neon engine
Ford Modular engine V10
Ford Taunus V4 engine
Buick 3800 V6
General Motors Corporation Quad 4 and Ecotec
GM Atlas engine four- and five-cylinder engines (two balance shafts)
GM Quad-4 engine, as used in the 1995 Pontiac Sunfire.
GM Vortec engine V-6 (single balance shaft)
Honda 2.2 L (F22) four cylinder engine
Kawasaki Kawasaki Z440LTD
Mazda's 2.3L MZR engine (two balance shafts)
Mitsubishi 'Astron' engine
Nissan 2.5L (QR25DE) four-cylinder engine
Porsche 2.5L, 2.7L and 3.0L inline four-cylinder engines
Subaru EF engine
Tata Nano
Toyota 2.4L (2AZ-FE)
Saab H engine
Volvo B234F, B204GT and B204FT (four cylinder, two balance shafts,
16V-head, used in 700 and 900 series)
VAG BHW 2.0L turbodiesel (Volkswagen, Audi, Skoda) (4-cyl, two balance
shafts, chain or gear drives)
As well as numerous motorcycle engines, particularly vertical twins,
and even some small single cylinder engines.
============================================================
--
BottleBob
http://home.earthlink.net/~bottlbob
Cliff
I'd think you could make it all a two-dimensional function of
crank position & time.
Or perhaps just one-dimensional using crank position.
--
Cliff
Curly Surmudgeon
Actually, no. Look at BB's link.
> Or perhaps just one-dimensional using crank position.
No way.
Curly Surmudgeon
wrote:
Sorry, I was being flippant. Sure the balance shafts help but the degree
of help is debatable. If we were to follow Ed's strict threshold then no
balance shaft is sufficient to offset the forces entirely. I see his
point but mitigate theory with reality.
Requiring an internal combustion engine to idle & run on a flat floor
without moving is excessive. All modern engines, the Geo 3-banger
included, are sufficiently "balanced". It's a matter of degree.
Note that I, too, questioned his statement above which initiated this
thread. Technically Ed is correct, no engine is perfectly balanced but
all are sufficiently balanced.
<snip>
> Volvo B204GT (four cylinder, two balance shafts,> 16V-head, used in 900
series)
Had one of these. Disconnected the balance shaft to improve mileage and
get rid of the gear sound. Ran fine with just a tiny bit of rough idle.
robert bowman
> I interpreted your inquiry of "balance" as counterweight offset. Looking
> at the theoretical it's much more complex than primary or secondary
> "balance" in the theoretical sense. As Bottlebob's link shows, it is 3-
> dimensional vibrational vectors, harmonics plus pitch, yaw and roll too
> however that article doesn't even touch the valve train vibrational
> components...
The saddest comment was when Honda took the nice, smooth Shadow engine and
reworked it so it would vibrate like a Harley. When I was looking for a new
bike, the salesman fired one up and proudly pointed out that the mirrors
vibrated just like a hog. Since I'm very familiar with the use of Loctite
to keep the bits and pieces from falling off a real Harley, I didn't
exactly see that as a leap forward. Of course, Harley screwed with their
first FI model to make it idle as roughly as the traditional engine.
BottleBob
> On Tue, 22 Dec 2009 22:18:34 -0800, BottleBob <bott...@earthlink.net>
> wrote:
> <snip>
>> Volvo B204GT (four cylinder, two balance shafts,> 16V-head, used in 900
> series)
>
> Had one of these. Disconnected the balance shaft to improve mileage and
> get rid of the gear sound. Ran fine with just a tiny bit of rough idle.
CS:
Here is a little personal anecdote from when I used to drag race
Vettes with 454 cu. in. big block engines. I'll copy the essentials of
a post I wrote a decade ago in a car newsgroup.
It even has (Gasp!), metalworking content. LOL
===========================================================
That reminds me of a time when I burned a couple
of pistons and it was too late to buy any for my 11:1 big block, and I
wanted to race badly Saturday night, so I took 4 13:1 pistons I
had laying around to my work and milled the domes down to approximately
11:1 dome size. When I was finished I pushed on the center of the dome
and my thumb went right through! Major screw up there. :)
So I went to a friend of mine that was a welder and had him weld and
fill up the underside of the dome. I weighed the pistons when I got
home and they were 26 grams heavier than the stock 11:1's (usually
pistons are balanced to within a gram or two of each other). I put the
4 cut down 13:1 pistons in the right bank of the engine. I made it in
time for the races and even had a couple of money wins. The car
vibrated pretty bad around 6000 rpm so I just short shifted in all the
gears and just let it vibrate in 4th at the big end. That engine
lasted for months like that.
Moral of the story? Measure the dome thickness before any
custom milling. :)
===========================================================
--
BottleBob
http://home.earthlink.net/~bottlbob
Curly Surmudgeon
wrote:
Rotational force is omega squared * radius. Double the RPM and force
squares. If I remember correctly a 4oz wheel imbalance is something like
32 _lbs_ of force at 100mph!
Engine components don't suffer near that imbalance as they're machined
and roughly balanced at the factory. Race motors are usually within a
static gram so even at 8,000 rpm imbalance is trivial.
You proved that.
HH&C
wrote:
> http://www.nytimes.com/2009/12/19/business/19brand.html
> “It was designed to provide transportation under miserable weather
> conditions.”
>
> I worked with a ComputerVision programmer that had one.
> --
> Cliff
Not too small to fail even though there's a ton of TARP money left
over.
I guess all that TARP money is being held in reserve for the districts
where Dems are likely to lose seats.
Cliff
http://ptc.com/appserver/wcms/datasheet/main.jsp?&im_dbkey=65296&icg_dbkey=841
http://ptc.com/appserver/wcms/datasheet/main.jsp?&im_dbkey=65291&icg_dbkey=841
http://ptc.com/appserver/wcms/datasheet/main.jsp?&im_dbkey=65352&icg_dbkey=841
http://ptc.com/products/cadds5/interactive-surfacing-option
http://ptc.com/products/cadds5/manufacturing-option
Etc.
There's quite a bit more <G>.
http://ptc.com/products/cadds5
HTH
--
Cliff
Ed Huntress
"Curly Surmudgeon" <CurlySu...@live.com> wrote in message
news:hgs6fp$rnq$1...@news.eternal-september.org...
Yeah, it is, if you really like engines. I think that Bottle's link,
combined with the history of engine design before we had much computer
analysis, wraps up the subject pretty well.
If you want to see some of the different angles that are taken on the design
side today, the SAE site has literally hundreds -- maybe thousands -- of
papers concerning engine balance. You can only read the abstracts without
buying them but even they provide a lot of information you won't find
elsewhere.
--
Ed Huntress
Curly Surmudgeon
<hunt...@optonline.net> wrote:
Actually I've had BB's link open for a week and occasionally read another
6-10 pages. Very well written to the point of over making the point but
I like that it includes the mathematical model.
> If you want to see some of the different angles that are taken on the
> design side today, the SAE site has literally hundreds -- maybe
> thousands -- of papers concerning engine balance. You can only read the
> abstracts without buying them but even they provide a lot of information
> you won't find elsewhere.
Naaah, this one is quite sufficient. Maybe my threshold of vibration is
lower but I don't find any production engine "unbalanced" or
objectionable. As I said, I disconnected the counterbalance shaft on our
old Volvo. I also drove V8's with high lift and long duration cams on a
daily basis. Personally I think people want too much, if they want to
ride on a couch take the train... Motor vehicles should be finicky,
gives'm personality.
Ed Huntress
Then you would have loved my AC Aceca. Bristol engines were God's gift to
people who like finicky engines. <g>
--
Ed Huntress
David R.Birch
At least the Saab 9-2x owners can still get parts and service at your
friendly local Subaru dealer.
Talk about cynical ideas, a Saab badged Impreza Outback Sport!
David
oldjag
> "Curly Surmudgeon" <CurlySurmudg...@live.com> wrote in message
>
> news:hh2uvb$33p$1...@news.eternal-september.org...
>
>
>
> > On Fri, 25 Dec 2009 11:06:25 -0500, "Ed Huntress"
>
> >> "Curly Surmudgeon" <CurlySurmudg...@live.com> wrote in message
FWIW;
The Saab V4 I had, (AKA Ford Taunus), had a balance shaft and was
quite smooth running. The balance shaft stuck through the front timing
cover and was what drove the fan, alternator and water pump. The
crank did not extend through the cover at all, and the pulleys were
approx 1:1 in size as I recall. When I ran my first SCCA race in my
'67 E Jaguar, there was a fellow with a fairly well modified V4 Saab
Sonnet. Said he shifted it at 8500 rpm. Not bad for a pushrod motor
in 1980 that did not have the benefit of a lot of aftermarket parts.
Also I happen to have a 1990 5 cylinder Audi 200 Turbo Quattro. The
only clue that it's a 5 cyl. from inside is the exhaust note, which is
more horse than a 6 cyl. Vibration in the car is nil, partly because
the balance Audi struck is a good compromise, it's only 2.2L, and
partly the liquid filled motor mounts. This car is at 247K miles now,
was chipped to run 15psig boost at 100K miles and still uses very
little oil...just made a 6k round trip to Colorado, (mostly under 100
mph), and still at the full line. Amazing engine durability, of
course fresh Mobil 1 every 7k miles helps a lot.
My E type racecar has 4.2L six that is very smooth up to about 5500
RPM, beyond that it get a little rougher, (I have solid motor mounts
on the race car). The seven main crank which weighs about 75 lbs. on
this engine, is typically fitted with a larger damper and a very light
flywheel for racing. With the lighter flywheel, Carrilo rods, and
bigger damper the crank survives 7500 rpm without too much trouble.
With a 4.125 stroke I guess a I should be happy the vibration at 7500
is not worse than it is..
Ed Huntress
"oldjag" <msmit...@comcast.net> wrote in message
news:a7aefb02-75c1-4cbb...@33g2000vbe.googlegroups.com...
Wow. My '58 Alfa Romeo, only 1300 cc., hit 4,000 fpm piston speed at only
8200 rpm. That was considered the limit for a racing motor in those days but
of course they go higher now. Still, 8500 on the V4 is pretty impressive.
>Also I happen to have a 1990 5 cylinder Audi 200 Turbo Quattro. The
>only clue that it's a 5 cyl. from inside is the exhaust note, which is
>more horse than a 6 cyl. Vibration in the car is nil, partly because
>the balance Audi struck is a good compromise, it's only 2.2L, and
>partly the liquid filled motor mounts. This car is at 247K miles now,
>was chipped to run 15psig boost at 100K miles and still uses very
>little oil...just made a 6k round trip to Colorado, (mostly under 100
>mph), and still at the full line. Amazing engine durability, of
>course fresh Mobil 1 every 7k miles helps a lot.
>
>My E type racecar has 4.2L six that is very smooth up to about 5500
>RPM, beyond that it get a little rougher, (I have solid motor mounts
>on the race car). The seven main crank which weighs about 75 lbs. on
>this engine, is typically fitted with a larger damper and a very light
>flywheel for racing. With the lighter flywheel, Carrilo rods, and
>bigger damper the crank survives 7500 rpm without too much trouble.
>With a 4.125 stroke I guess a I should be happy the vibration at 7500
>is not worse than it is..
Again, that's some rpm. I was reading an account of Jaguar at LeMans in the
'50s a few years ago, and I remember that the redline on the LeMans D-types,
in '55, was 6,000. That worked out to exactly 200 mph, which, said Jaguar's
engineer/driver, it would just touch at the end of the Mulsanne Straight
(there was no Ford Chicane in those days).
Maybe you know -- I can't recall -- but the '55s might not even have been
3.8L. They might have been 3.4s.
Anyway, at 7,500 with a 4.125 in. stroke, you're running at over 5,100 fpm
piston speed. Things have improved a lot. I don't think I could have kept
the rings in the pistons at that speed, in 1966. That was a Tom O'Brian
motor, BTW, first-class stuff.
--
Ed Huntress
oldjag
> "oldjag" <msmith5...@comcast.net> wrote in message
Yeah, I think the '55's were 3.4L. I don't have much trouble with the
rings, I use gapless rings that are quite a bit narrower than stock
and the pistons are gas ported on the top ring. The 13:1 pistons are
set up a bit loose in the bore, rattle a little when cold, but once
warmed up they are quiet. Love to know what the car would do on a
long straight with taller gears. The 3:54 gears in the car give about
170 mph @ 7200 with the tires I run. I though about destroking once to
allow higher revs, but have been talked out of it as giving away too
much displacement. In any case I knew one fellow running a 4.2L
stroked to 5.0L which required among other things a 5 inch stroke..he
only rev'ed it to 6800 though. Only reason I guess you can get away
with this is the 7.125" long rod centers in Jag engines keeps the
piston acceleration down. For survival at high RPM the cranks in
these old engines have to be nitrided, have very straight crankpin and
main journals, spot on bearing clearance and a decent dry sump system.
The exhaust note on this car from the side pipes is really nice at
7500, (good if sound control is on the infield side of the track:)
Ed Huntress
I'll bet it sounds great. You must be getting some serious horsepower. When
you mentioned 170 mph, I recalled that was the speed at which the D-types
tended to go weightless in the rear, which was the inspiration for the
vertical fin on the long-wheelbase model. I suppose you have some kind of
spoiler to keep the rear on the ground?
Also, you're talking about a '67 E-type and it sounds like you were racing
in the '80s. I remember a '67 that raced at Lime Rock Park sometime in the
mid-'80s. IIRC, the guy had blond hair. The car was red or maroon. (I was a
SCCA tech inspector in those days.)
Was that you, by any chance?
--
Ed Huntress
oldjag
I ran at Lime Rock in the '80s but I don't have blond hair, the car is
a red roadster though. There were a few others running E's at the
time. I remember a black coupe at the Runoff's once. Eventually the 6
cylinder E type got moved into GT2 and was allowed a rear spoiler
which seemed to make the car seem more stable under high speed braking
at tracks with long straights like Summit Point. I ran nationals and
did the runoff's at Mid Ohio couple of times in the late 90's in GT2.
Mid Ohio is a wonderful track, perhaps second only to Bridgehampton,
(I ran the last race at Bridgehampton before it closed).. Since then
the car has been used a few times for local stuff, but other projects
and dive trips have soaked up the time and money to run it in GT2.
Tires at about $450 a corner, and race fuel up to $9 a gallon, $3 a
gallon towing fuel kinda runs up the cost of a weekend. Amazing fun
though..
Ed Huntress
Ok, I'll bet that was you, then. I only remember one red '67 E-type roadster
that raced there at that time. I probably just misremember your head. <g>
If that was you, I think I inspected your car once. I also inspected for
CART, at the Meadowlands GP. Were you in the North Jersey SCCA chapter? Do
you remember Bob Connell (ITC Fiesta)? After he T-boned an RX-7 with his
first Fiesta (yellow, I think), I sold him one of my chassis and he raced
that. It was red, if he didn't re-paint it. I also gave him an engine. You
needed spare heads if you were going to race a Fiesta. They cracked. The US
versions (it was basically a 125 New Kent) were very thin to meet US
emissions standards.
>There were a few others running E's at the
>time. I remember a black coupe at the Runoff's once. Eventually the 6
>cylinder E type got moved into GT2 and was allowed a rear spoiler
>which seemed to make the car seem more stable under high speed braking
>at tracks with long straights like Summit Point.
The accounts of the LeMans D-type drivers, of having the rear end float
around at the end of the Mulsanne Straight, at close to 200 mph, made me
realize those drivers were made of some very unusual stuff. <g>
> I ran nationals and
>did the runoff's at Mid Ohio couple of times in the late 90's in GT2.
>Mid Ohio is a wonderful track, perhaps second only to Bridgehampton,
>(I ran the last race at Bridgehampton before it closed)..
I never got to Mid-Ohio. I did my novice races and a regional at Lime Rock
(MG Midget 1275) and weekend races at an airport track in Michigan. I can't
even remember where it was -- Walled Lake? -- until it got too expensive for
me. That was 1969 - 1972.
But I do remember Bridgehampton, where I watched several races in the
mid-'60s. I got to shake hands with Briggs Cunningham there. 'Never raced
there, though.
>Since then
>the car has been used a few times for local stuff, but other projects
>and dive trips have soaked up the time and money to run it in GT2.
.Tires at about $450 a corner, and race fuel up to $9 a gallon, $3 a
>gallon towing fuel kinda runs up the cost of a weekend. Amazing fun
>though..
Ouch! I paid $2,365 for my Midget -- new. <g> I put another $600 or so into
a roll bar and harness, 1-1/4" SUs, a Racer Brown 3/4 cam, and a set of
Goodyear Blue Streak Sports Car Specials. That was GP then. My rain tires
were the Pirelli Cinturatos I used to drive the car to school and work. The
Blue Streaks went into a big plastic bag between races, and they wore like
iron. They sometimes cornered like they were made of iron, too. <g>
You may not remember this, because things had changed substantially by the
'80s, but that produced a fairly competitive car in '69. Two years later
things changed suddenly in weekend racing. A new young crowd, many of them
engineering students and engineers, came in with $5,000 engines and blew the
rest of us away. I couldn't keep up with a 130 hp Midget. I had maybe 105 -
110 hp, guessing from performance.
In the early '80s I tried to re-start on the cheap, with an ITC Fiesta, but
I was a diabetic by then and the regional medical doc, in Philadelphia,
didn't want diabetics on the track. SCCA national tried to support me and
encouraged me to appeal, but that, too, was getting expensive. And my wife
wanted to have a baby. Everything combined to make me give it up. So I took
up tech inspecting and had my fun vicariously.
--
Ed Huntress
oldjag
I was in Phila Region... funny you mentioned the Ford Fiestas. I had
a first gen Fiesta not long after the Saab. Another car that was more
than the sum of its parts, they ran a lot better than you would think
a little pushrod four would. I think at the time they were a little
quicker in stock form than the VW rabbit or any of the other small FWD
cars.
Ed Huntress
<snip>
> I was in Phila Region... funny you mentioned the Ford Fiestas. I had
> a first gen Fiesta not long after the Saab. Another car that was more
> than the sum of its parts, they ran a lot better than you would think
> a little pushrod four would. I think at the time they were a little
> quicker in stock form than the VW rabbit or any of the other small FWD
> cars.
When they ran as production sedans, before there was an Improved Touring
class, they gave the Rabbits fits. Their only problem was tiny wheels and
brakes -- they didn't stop. But they were able to use bigger wheels and
brakes in ITC. I made those changes to my first Fiesta, and it was better
that way as a road car, too. (ITC rules also allowed the use of a
then-popular Weber downdraft carb, which I also had on my road car. It made
for a very fast Fiesta -- until you had to go through emission testing.)
I liked the New Kent engines and knew them somewhat, from the time I worked
on a 115E Kent in a Morgan 4/4. That engine would rev, and it had, or could
fit, pretty big valves. It was a brilliant design, right from the original
105E -- the English equivalent of the Chevy Small Block, in terms of its
racing versatility.
My old college roommate has a Lotus 7 Mk IV, one of the 50 that were brought
into the US through Canada, gray market (it's now in Tyler, TX). On my
(mistaken) recommendation, he had a Pinto version of the 125E engine put
into it, instead of the Twin Cam that was recommended. I'd worked on a Lotus
Twin Cam owned by another friend and figured he'd be in trouble without a
mechanic around who knew the engine. Any Ford dealer would be able to
service the Pinto. But the Pinto had radically different electrics and he
had to re-wire most of the car. <g>
I took a couple of laps at Lime Rock Park in a Lotus FF with the 115E Kent
engine. In an open-wheeler, it felt like a real race engine -- crisp and
responsive.
--
Ed Huntress