Twin Herb Adams '71 SCCA Trans Am '64 Tempest Gray Ghost projects

[HQuackenboss]

A picture is worth a thousand words.

[DoctorLarry]

is that near the oil filter? Is that the orange on the left side of the picture?

[HQuackenboss]

I think the orange is the bell housing. I think if you rotate the picture sideways so the fitting is horizontal that it will be easier for you to orient everything. The tube is a header pipe.

Edited February 5, 2019 by HQuackenboss
Further explanation

[DoctorLarry]

Good description of the pump on the SD 455 block, but no pictures of the outlet location:

https://www.hemmings.com/magazine/mus/2008/08/The-Guts-Inside-the-Glory/1676887.html

[swede70]

Here's a flood of images that may pull things together.  Understand that the flow of oil is carried to a pair of Harrison oil coolers situated to the left and right of the radiator further forward. If it would help, I could post images helping to track how things were routed.   The dry sump system oil tank is clearly well-buried in the firewall, while what line pours oil in and which draws the same out will be readily inferred.  Thanks...

...I have other images, although some simply eliminate possibilities for revealing little.  Thanks...

Mike K./Swede70

Edited February 6, 2019 by swede70

[DoctorLarry]

That nails it! Thanks, Mike. Harry-did the Grand Am use the same rear suspension setup as the Ghost? Mike has some really good shots of it and if Herb Adams used the same basic architecture I will have all I need to finish. Thanks, guys!

[swede70]

Pleased to read that the images were of help then...

Regarding the rear suspension of the Gray Ghost and mulling what was spoken of before, I thought it best to revisit this aspect of the project for including another photo. This would be from the A.B. Shuman penned and photographed  September 1971 Motor Trend article titled Ask Herb's Wife If We Can Take Her Car Racing.  Apparently earlier in the season an off the shelf G.M. rear sway bar, quite literally a bolt-on piece absent links or means of adjustment, was employed on the vehicle.  Notice too that the geometry-altering structure affixed to the top of the differential housing hasn't yet been worked up and fitted.  Finally, know that the odd rectangular structure seen to the upper right masks one of the the pair of Holley fuel pumps situated at the forward corners of the fuel cell, these positioned below the level of the floor as spoken of before.   This is the only period image I know of the car from this angle, while efforts to turn up further photos; i.e. those unused and unpublished from the A.B. Shuman session conducted that day via the P.P./SEMA archive have not met with success.  Perhaps such may be added onto the archive in time, but as this was written none are to be found regardless of how dexterous one is for mixing up search terms. Thanks...

Mike K./Swede70

Edited February 6, 2019 by swede70

[DoctorLarry]

If you look at this, neither the upper or lower control arm mounting positions have been altered. The upper arms are steel tubing with spherical rod ends but the lowers are stock with a stock sway bar and mounted in the stock locations.  The team must have altered the geometry later to improve handling. With the altered lower mounts I doubt the stock sway bar would have fit anymore so they must have ditched it.

[wisdonm]

It looks like the axle tubes are bolted to the rear end housing,(not stock?). Is this where the negative camber is achieved? If not, how was it done?

Edited February 6, 2019 by wisdonm

[DoctorLarry]

Check out the parallel Team Associates Grand Am thread on the NASCAR board-Mike has posted the modified rear suspension photo that shows the modified mounts on the rear axle for camber changes.

[HQuackenboss]

I need to do some memory refreshing before I can answer about the NASCAR Grand Am Winston Cup car, but a few things on the Tempest:

1. The flanges in the rear axle are close to the center section, but there is a section of tube between the center section and the inner flange on each side. This scheme served two purposes:

a. Different tracks needed different rear end gear ratios to optimize top speed, and occasionally to tweak gear/RPM range exiting corners. It was judged that swapping center sections was easier than changing internal gears and adjusting the lash at the track.

b. We used negative camber, about 1 degree per side. The rear flnges were welded to the cut tubes to provide this adjustment. 

The Tempest was the only race car this removable center section.

2. The upper rear control arms were replaced with tubular links with rod ends, sometimes called Heim Joints, which is a brand of rod ends.  After the Motor Trend article was done, the upper and lower links were relocated to move the pivot points on the axle lower, and the pivots on the body, higher.  The reason was to increase the % anti-squat (Google will tell you more, but don't believe the explanation in Caroll Smith's book (I think it is "Engineer to Win"), because he got it 100% wrong.

3. About the same time, the rear sway bar style, originally the same as the GM A-body production cars used, a wide U bolted to each lower control arm, was changed to a 1970 1/2+ production Firebird/Camaro style, although since the rear axle is a bit wider, custom bars were bent, and since the Firebird used leaf springs, the mounting to the axle was changed so that the U shaped clamps bolted to the same bracket the rear shocks were attached to, instead of to the bottom of the leaf spring plate on the Firebird/Camaro.

 

[DoctorLarry]

Great. Thanks, Harry! LB

[DoctorLarry]

Harry-any thoughts come to mind on the Grand Am rear suspension?

[HQuackenboss]

DoctorLarry,

I hadn't forgotten your question, and I am sorry for taking so long.

My recollection was that the Grand Am used a rear suspension setup that NASCAR Winston Cup rules dictated, commonly called a "truck arm" rear suspension.  Probably because I have spent so much time looking at and thinking about the GM 4-link suspension as used on the John Hildebrand's Gray Ghost, my memory was cloudy, and I didn't want to answer with a guess.

But a phone conversation with Herb Adams confirmed that is what it was. I don't have any pictures of it, but there are many pictures you can find online by doing a search for: NASCAR truck arm rear suspension

like this one: http://67-72chevytrucks.com/vboard/showthread.php?t=337006&page=3 

[DoctorLarry]

Thanks, Harry. I was going with the 4 link but now I can do it more accurately! I That was where I started before I saw the Petersen archive photos and read all of your comments. I can finish my chassis up now. Thanks again-we have really put you out for a couple of models! Larry

[DoctorLarry]

Do you know if they used a Watts linkage or Panhard bar to control side movement?

[HQuackenboss]

Yes. A Panhard rod. In NASCAR land, they call it a track bar

For future reference, in case anybody ever gets an uncontrollable urge to build a model of the 1972 Minter Firebird Trans Am Trans-Am racer, it used no added lateral location.

[DoctorLarry]

Hopefully this has not been an exercise in answering repeated questions from pestering students.....

[DoctorLarry]

Another question relating to all three cars: The Gray Ghost ran Minilites on it in all of the photos of the car.  I assume that they never used anything different on it. Photos of the Minter Firebird show it with Motor Wheel Spyders on it. Some of the Petersen photos of the Grand Am appear to show it running Spyder wheels on it. Did that happen or is it just the way the photos look? The photos of it sitting still show the 5 hole Nascar type wheels but the motion photos look different to me. If you blow this up the wheels look a lot like Motor Wheel.

[DoctorLarry]

I read somewhere else that for a test version of a Firebird they had at Pontiac that Kelsey Hayes supplied the wheels which looked a lot like Motor Wheel. Did the Tempest use Minilites for weight or because the team was paying for their own parts?

[HQuackenboss]

DoctorLarry,

The Tempest used Minilites, which were purchased by the team. The core engineers ( I was not one) put up money to fund the team.  At the end of the year, the Minilites were sold to a Trans-Am racer with a first generation Camaro.  The last race for the Tempest was a club race at Waterford Hills at the end of 1971, and it had a set of the Motor Wheel Spyders identical to what we used in 1971 on the Firebird.  Ours were under a parts sponsorship (my recollection it was just the wheels, no cash). My guess is that Motor Wheel (a subsidiary of Goodyear) also supplied the wheels that Dick Hofffman under a similar parts sponsorship.  They worked great. We never had a problem with them. But with steel rims riveted to an aluminum center, they were heavier than the Minilites.

I would be curious about the reference to Kelsey Hayes. 

[DoctorLarry]

This was from a Martyn Schorr book about Pontiacs-section on an engineering prototype Adams put together at Pontiac. They reference Kelsey Hayes supplying the wheels which look almost exactly like the Motor Wheels. Did the team ever test them on the Grand Am? It sure looks like it in that photo I posted.

[HQuackenboss]

Regarding the Motor Wheel Spyders on the NASCAR Grand Am in the picture, we ran steel wheels identical, except for chroming them, just like everybody else in NASCAR Winston Cup used.The photo you posted was from a test session at Willow Springs before the 1973 NASCAR Riverside race.

I don't recall the details of when we got the wheels, but those were, my guess, leftover Trans-Am wheels and tires, and we probably didn't even get the NASCAR tires until we arrived at Riverside after the session.

I remember there was a lot of discussion about chroming the wheels. Folklore was NASCAR racers didn't use chrome wheels because of concern about the chroming process making the steel wheels brittle because of interaction between hydrogen and the steel. Somebody, probably a metallurgist at Pontiac, said by baking the wheels after chrome plating, the hydrogen would be removed.

Subsequently Richard Petty used chrome plated wheels for a while.

[HQuackenboss]

DoctorLarry,

My strong opinion is that in this rare instance, Marty Schorr is wrong about those being Kelsey Hayes wheels. Those, my opinion,  are Motor Wheel Spyders.

[DoctorLarry]

The Motor Trend story referenced the chrome wheels. Evidently chroming caused hydrogen embrittlement on the wheels and they were indeed heat treated afterward to eliminate that. My opinion is that you are correct. Those really look like Spyders to me. The Motor Trend story also said that the wheels flexed so much that one of the bleeder screws on a caliper was ground off causing a brake pressure loss that they had to fix.