<VV> Cam Engine - All you wanted to know about the cammer engine. REALLY LONG

[Rick Loving]

Here is a little blip I wrote about the cammer engine and interesting story
posted on VV a long time ago...

The GM Prototype engine that was displayed as the planned power plant for
the Corvair Astro concept car was a significant leap forward as compared to
the stock Corvair power plant.  The stock bore was enlarged from the stock
3.43 inches to 3.56 inches. Combined with the stock 2.94-inch stroke, the
displacement grew to 176 cubic inches or 2,885cc. Although it is truly
unique design, the basic form of the Corvair engine is apparent.  Changes to
the crank case were needed but the basic proven design was carried on.   The
most noticeable similarity is the fuel pump, oil filter housing, and
distributor which appear like stock parts.      
The heads, as designed, have nearly hemispherical combustion chambers with
inclined valves in a pent roof setup that is similar to a Porsche.  The
angled chamber smoothes out the port flow reducing the severe bends for both
the intake and exhaust that the stock Corvair head flow is forced to take.  
The valves are operated by two single overhead cams, driven off the
crankshaft by a pair of Gilmer style toothed belts.  This belt drive setup,
coupled with improved port flow allowed for more breathing and rev potential
than the production pushrod-operated units ever could.
The crank also served to drive the cooling system and electrical charging
system, the crank pulley was a double-sheave pulley using twin belts to
drive a trio of centrifugal cooling fans and an alternator.
The three cooling fans appear to be a scroll type compressor fan setup, all
driven off a single common shaft. They appear to have a focused outlet
configuration (instead of a constant outlet like the stock horizontal
cooling fan) which presumably makes for higher pressure output air.  Each
fan's airflow cools an opposed pair of cylinders and heads exhausting out
the bottom of the head.
The intake manifolds mate the heads to a pair of specially designed GM
prototype 3 barrel carburetors.  These carburetors were designed based on
the Weber IDA carburetor's but were actual GM castings.  The use Weber
internals and design principles but the bodies have been widened to place
the carburetor barrels right over the intake ports, giving the air-fuel
mixture a straight shot at the valves. 
The modification of the carburetors was necessary because of bore-to-bore
differences between the Corvair cylinders and the Weber IDA carburetors.
The stock Weber IDA's bore centers are much narrower and require the outer
intake paths to make a sharp bend to reach the end cylinders when centered
on a stock Corvair.
Designed as a high output unit, this 2.9-liter flat-six was rated at 240hp
at 7,200 rpm rating it at 1.4 horsepower per cubic inch for an air cooled
naturally aspirated engine.

Here is the story posted about a supposed sighting of the cammer engine....


<SNIP>
GM built several of these "cammer" engines. They displaced ~170ci or
thereabouts and made some respectable horsepower.   No cammer engine was
ever installed in the Astro.    One of the engines *did* make the car show
tours with the car, but it was mounted on a stand and not in the car.

Last time I picked and dug through the Astro-1 it had a 140 engine in it, or
at least the engine was sporting 4 carbs, not running of course.   The car
oddly enough did have an electrical system... which you plugged into a wall
outlet to work things.    It was never intended to move under its own power
although it likely could be made to do so with a little (OK,a LOT) bit of
engineering work provided someone wasn't afraid to do some mods, which of
course will never happen.

According to scuttlebutt, GM scrapped the cammer engines when the Astro was
done with the car show circuit, supposedly.   It's not quite clear how many
engines were built, but there were more than just one for sure, likely
several more; one person said they'd been told there had been at least 7
engines assembled, but that's just hearsay.

Now:    (I've told this story before)

I did some chasing around and digging, picking and poking people's minds as
well as scrounging for eye-witness accounts anywhere I could find info, as
to what became of these engines.    I turned up some odd info from two
different people regarding a "back door deal" which involved somehow who
managed to sneak one of these engines out and away, whereupon it ended up in
a late coupe.    This particular story came from a non-Corvair (Camaro
fanatic from Back When) guy who had attended a muscle car get-together and
was talking about Camaros with some other people when someone brought up
Corvairs whereupon the anecdote came up.   It seemed this fellow's cousin or
someone was acquainted with the person with the Corvair and while "hanging
out" with the circle of friends, he'd gotten a look at the engine 
in the car which had odd 3xbbl carbs and cams in the heads driven by belts,
oddest thing he'd ever seen, whereupon I'd perked up big time, and asked for
more details.

The guy said that his cousin (or whoever, I forget the exact relation since
I was sidetracked) had told him that the Corvair guy had relatives who
worked for GM or he in fact had worked for GM in some capacity, and wanted
one of the engines which along with others were slated to be cut up and
recycled.   Supposedly, this guy had gotten access to the vicinity where the
engines were sitting on pallets awaiting the choppers, sneaked one of them
out and replaced it with a standard Vair engine, figuring that the choppers
wouldn't know the difference or care one way or another since they just
counted pallets and cut up what they were sent.   Supposedly it was a
weekend evening foray, Monday the pallets were unloaded and cut up, so said
the Camaro guy.    He went on to describe the engine in some detail as I
listened closely.

He  asked about when the engine had been available for production Corvairs
(I guess he thought it was an option) and I told him that GM never did
produce this engine outside of building a scant handful of prototypes and
that supposedly they'd all been destroyed and where did this fellow get the
engine?   Who was he, is the car still around, what's the deal, what was his
name...  whereupon the guy got spooked, clammed up, drifted away from me and
disappeared not to be seen again.

I tried to chase him down but he was gone.    I don't know whether or not
the story was bogus or what...

Later on, about a year or so, I talked briefly to a guy who said he'd seen a
Corvair at an autocross (never did say where) many years earlier which had a
"special optional 6 carb DOHC engine with three blowers on it" that "ran
like stink" and was "...originally slated to be a part of GM's race program"
or some such...  most of which was complete embellishment BS.   I pressed
the fellow for details, being careful not to spook him the way the first guy
was, and this 2nd guy talked about the engine, said he'd seen it up close,
and was "sure" it had been a special performance option in Corvairs (which
of course it was not).    When I'd mentioned that the only OHC engine that
GM ever built for a Corvair had a single  cam in the heads, he insisted it
was a DOHC because he'd "...seen the gilmer drive belts running the cams in
the heads".   I didn't pursue the matter.   I did ask him about other
details and he rattled on about the "triple blowers" atop the engine (the
three squirrel-cage cooling fans the "Cammer" engines used?) which I also
didn't try to correct.   He then started in on how Nader had stopped Corvair
production because they were fire hazards (I'm serious) and (of course) they
rolled over in corners, followed by an unsolicited description of Corvair
engineering, design, and history which was pretty much about 50% pure
fabrication.

The guy was basically a Barney Phife sort, but his description of the 
engine in the car was suspiciously accurate for the Astro "cammer" 
engine.    I'm still not sure whether to believe his story or not, seeing as
how so much of what he'd said about other things was so bogus. Add to this
the fact that he looked a little like Burle Ives, only fatter...  I found
him just a little hard to take seriously.

Then, a couple years later, I had a chance to talk to Dave Newell at a show
and told him what I'd heard, and he related a similar story that he'd dug
up, regarding the "purloined engine" which, according to his info, had by
hook or by crook ended up hiding out in the engine bay of a Vair owned by
the son of a GM white-collar sort... and had evidently been seen on the
roads and in public a number of times.    This sounds like the story I got
from the guy whose cousin knew somebody...  the Burle Ives guy offered up
little or nothing as to details of the car, its owner, or where he'd seen
it, only that he'd seen it at an autocross somewhere.

Made me wonder... autocrosses as a rule haven't really been all that 
popular as events until the '70s or so, from what I've seen (nothing like
their popularity today) and if this engine had indeed been swiped from GM,
it must have been done in the mid'60s...  making the car in question likely
already accumulating close to ten years on the clock by the approximate time
"Burle" said that he saw it.    It's possible that "Burle" may have simply
seen a Weber equipped Stinger and "took that ball and ran with it" when
asked about it... or maybe he did see the same engine we're talking about.

Now, the guy with the cousin said that he'd seen the engine back when 
Camaros were first coming out, and only noted the Corvair as an item of 
interest because it "looked like the new Camaro".    The timing is about
right... and the cousin-guy didn't know much of anything about Corvairs so
I'd wager that he wouldn't have been privy to details of the Astro or the
cammer engine in any event, and that what he was telling me was bona fide.
Maybe.

Did one of these engines escape the scrapper's torch?   I'd like to think
so.   However, if it did, and if it somehow managed to indeed end up in the
back of a Vair owned by some character with friends/family in high places,
it hasn't resurfaced outside a few hearsay comments along the way.

There's no proof... just stories from people who saw something odd in the
back of a Corvair.     However, there exists some parts and pieces (carbs,
for instance) left over from the cammer's days, along with photos, technical
specs and engineering details, and some dyno pull data...  enough to suggest
that it certainly had performance potential.

In the meantime, all I have of substance is a really nice photo of the 
engine in a stand... same one that's available for viewing on Gary Aube's
web site.

tony..
<SNIP>

Hope this fills in some blanks...

Rick Loving



-----Original Message-----
From: virtualvairs-bounces at corvair.org
[mailto:virtualvairs-bounces at corvair.org] On Behalf Of D. Barry Ellison
Sent: Wednesday, May 21, 2008 3:16 PM
To: virtualvairs at corvair.org
Subject: <VV> Cam Engine


Hopefully, some of you historians (and shall we respectfully say, "more
experienced"? <huge grin>) can shed some light on the cammer engine for me.
 
I've got the cam engine picture as my desktop background.  Just looking at
it quickly, I've got a couple of questions.  
 
1. Cooling - there looks to be 3 fans running down the center, running on a
common shaft.  I see a whole for the rear fan intake.  Where were the
intakes for the other two?  They don't look to be on the rear.  Custom fans?
What kind?  (certainly not a Corvair of any type modified to work)
 
2. To my untrained eye, the timing belt looks to be one piece, not one
running each half.  I also see two tension pulleys, one on both sides.  How
could there be enough surface area on the crank gear to not allow the belt
to slip?  I've familiar with Honda engines and the timing belt runs over 270
degrees around it.  Guessing there's < 200 around this one.   What's the
minimum gear degrees/teeth needed to turn two cams pushing 12 valves?  Of
course it depends on the weight it's trying to move, and at what RPM as
well... but 'generally' is my question.
 
3. Can we even verify it ever ran?
 
4. What happened to this engine?  This pic is so perfect, I almost would bet
it's a digital pic, which would imply it still lives somewhere, but I
seriously doubt it.  Conjecture appreciated on that one. Seems we would have
heard about it.
 
5. Do parts/plans/drawings exist?  Again, Seems we would have heard about
it.
 
If I had unlimited funds, full machine shop, and experience with CAD/CAM,
we'd have one or two of these around!
 
"Inquiring minds want to know."BarryE in SC
2 lates, 2 earlies 
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