61 Tempest Project

The 326 was Pontiac built, iron block and Aluminum heads

 

Here's a little inspiration.

Sleeper Tempest from hell. Twin turbo'ed 427 Chevy painted poncho blue with the "326 8" air cleaner and the turbos hidden in back where the old transaxle used to be.

http://youtube.com/watch?v=NVKt1rebIi8

 

For some stupid reason Pontiac only offered the 4 speed with the 4 cylinder.I don't think that the transaxles were used in the Drag tempests but I don't know that for sure .I DO know my stock 326 would twist off the ends of the axles if i tried beating on it at all no holeshots or line locks for sure and it was PG can't see them standing up to 3 or 4 speed sticks at all

 

The '63 421 Super Duty Tempest wagons and coupes all used the Power Shift 4-speed auto transaxle that launched with a clutch. Super-rare and pricey as you might imagine.

Later on most of them were converted to a 'conventional' drivetrain layout and received a Pontiac 'big car' rearend.

All of the regular production '63 326 V8 Tempest/Lemans cars had a 326 with an iron block and heads. Aluminum 326 heads were made by Mickey Thompson, they never came on these cars from the factory.

 

65 and up Corvair share the same components as the full size chevys in the transmissions and the rear ends NOW I'm saying internals not cases but I do believe that the trans case is the same there is a tin plate at the front of the trans that when removed you can bolt a Chevy bell housing to somebody in Hot Rod magazine did that years ago for a mid engine Corvair he was a GM Engineer and Hot Rodder
If I remember he also swapped a conventional input shaft into the Trans case for the swap

 

Pontiac donated a complete Tempest drive line to our trade school it must have been some kind of show display because lots of it was chrome plated ! My freshman year It was my job to cut it up! This was in 69 and they wanted to make room for later model stuff to train on.By some glitch Donated vehicles/parts could not be sold.Lots of my tempest went into the scrap in place of the donated Tempest stuff.Guess you could call it a rat rod ! Primer spots on the body but the front suspension had a lot of chrome !

 

Here's some info that I copied and pasted from the Performance Years site, it gives details on the '63 SD Tempests and the transaxle/'rope' driveshaft used on all of the '61 -'63 transaxle Tempest/Lemans cars:

The 4-speed '63 Tempest automatic was called the PowerShift. It only came in the 6 Super Duty Lemans coupes and 6 Tempest wagons. (There might be a 13th vehicle somewhere). After NHRA kicked them out of a production class because of the limited production brought on by the GM "no racing" edict, which caught everyone by surprise, most folks replaced the transaxle with a solid rear. That's why Thompson had a few extra. To the right collector, a complete, operating PowerShift is nearly priceless.

It was two 2-speed planetary transmissions (like a Powerglide or TempesTorque)on either side of the Tempest final drive unit. The flywheel and either a clutch or torque converter was hung at the extreme rear end. This required shortening the fuel tank about a foot.

Power flow thru the PowerShift was interesting and complex: the "rope" driveshaft fed power into the input shaft via a splined connector at the front of the transaxle. This shaft went completely thru the front trans case, the final drive and the rear trans case to the flywheel/flexplate. From the tc or clutch output the power flowed back thru a second concentric shaft to the transmissions. From there it went back thru a third concentric shaft which was the pinion gear shaft.

First gear was about 2.43, which you get with front trans (1.76) in low and then thru the rear trans (1.38) in low (1.76 x 1.38 = 2.43). For second gear the rear was shifted into direct to get 1.76 from the front trans still in low. For 3rd, both are shifted: front into direct and rear back into low for a 1.38. 4th gear is both back into direct. While this sounds terribly complicated, that's how the old 4-speed HydraMatics worked, but with the two planetary gearsets in one housing. Clutch and band apply and release have to be timed well, especially on the 2-3 shift.

The clutch, as shown in the pic a few posts above, was a concentric hydraulic always turning throwout bearing. AFAIK, this might have been the first OEM use if this, now common clutch actuation. You can see it in the pic.

As far as the "rope driveshaft", it was an alloy steel torsion bar, about the hardness of an antiroll bar. It had a forged head at the front which bolted solidly to extra holes in the center of a Pontiac crank on the automatics (and all SDs) and to the clutch output shaft on the production manual, I believe. It was splined at the rear and approximately 80 inches long. It was bent into a gentle arc (maybe 3-4 inches max at the center)and retained in a upside-down U-shaped torque tube. It didn't really need the little bearings about 1/3 and 2/3 of the way along the shaft. They were just there to retain it if it broke or came loose from the engine and for installation purposes.

Pontiac build maybe 300,000 '61-'63 Tempests with this shaft. VERY few ever failed in the field. Producton automatics had 5/8 dia shafts and manuals had 3/4 dia. as did the Super Duty cars. You can demonstrate to yourself how it worked by putting a gentle arc in a piece of wire like 1/8 dia. music wire, and have someone turn it while it's in the arc. The rotation is transmitted smoothly without any sinusoidal variation like you find in a u-joint.

Because it's a torsion bar, it will wind up under high torque loads. In testing, I believe it wound up over 2 revolutions when a 389 or 421 WOT at hp peak was dumped into it from a clutch at the front with the rear fixed to the test fixture. It stalled the engine (and then unwound the 2+ turns). In the production Tempests, the TC was in the rear, but the manual clutch was on the engine. You could dump the clutch and feel a little of the windup/unwind. The 3/4 dia. shaft minimized that, but I think the 5/8 would have been plenty strong enough. The biggest production engine to use it was the '63 "326" HO (4 bbl dual exhaust), which you probably know was really a 336 cube engine. I don't recall if it used the 3/4 shaft for the 2-speed auto, but probably not.

Picture of the PowerShift transaxle assembly:

 

WOW didn't know my tempest was the HO version !I was a snot nosed 16 year old kid back then !I had just bought a 62 4 peed Tempest and planned to swap over the drive line when a drunk hit me head on at a stop sign and totaled the car.The money from that settlement bought me a 63 1/2 Ford 427 4 speed Galixie

 

WOW! What an incredible amount of Tempest info. I had no idea my little car could spark such interest. I had pretty much scoured the web over time and found most of this stuff over time and it is why I found the desire to find and buy the car in the first place. The cool thing about the HAMB is all the stuff that I had to dig for years to learn about this unique car was uncovered in a matter of two days on this forum.

There were a few post that surprised me - I hadn't seen the blown version that 29bowtie posted - that is pretty awesome. I can imagine what kind of noise that thing would make. I'm thinking I'll have to say on the slightly milder side of that set-up.

I like hearing everyones thoughts on what should be thrown at this car. However, in the end, I'm a sucker for oddity. The attraction to this car in the first place was the odd engine, and driveline. While I'm not sure how the project will unfold, I'm for certain it will include the original 4 and the original swing axle rear transaxle set-up. (and not to offend, but I'm defiantly not doing a Chev swap!)

There is a small photo from the "tripower nationals" in Car Craft (or maybe it was Pop. Hot Rodding- I don't have the book at home) that shows a 4cl tempest racer that runs 12's - Now that sounds cool.

I did get some new points plugs and condenser installed today and it smoothed right out. Now to fix the exhaust leak. This engine uses the exhaust cross-over to warm the intake. While it may have worked well when new, I had the same issue on my 59 Safari, the valve stuck and caused an awful mess. Not to mention the valve weighs a ton and actually lead to a cracked exhaust manifold on my old wagon. I'm thinking that is next to go! I'm looking forward to hearing the 4 run though a good sounding exhaust.

Thanks again for all the feedback!

 

That was Dave Johnson's car - Unfortunately, he passed away earlier this year. There is a bunch of info on his car over at the PY site, you can search for posts under his screen name, White Warrior.

 

thats the one i was thinking of, it was in car craft or hotrod recently. cool car.

 

I have a single Ram Air head that has been kicking around the garage for 20+ years. It would bolt right on there. A little whittling on a V-8 manifold... could make a really neat banger.

 

The Tempest used the same suspension as corvair, but in 63 Pontiac replaced the rear swing arm with a trailing link. How come they knew it had problems but chevy didn't? Then in 64 they replaced it all with a 'normal' axle and tranny, which lead to the GTO.

I have an old book on the 421s. They were wild cars, and could lap daytona faster than a corvette. Their hood scoop was off a ford dump truck.
One retired fellow obtained several 4 speed transaxles, and put one in a corvair with a Jaguar V12 in the front. Beautifully done.

 

Who is the guy in the white shirt?

 

????????? "Bounty Hunter DOG" from cable TV before he got the hair extensions??????????

 

I think it's a cool little car that you don't see many of. I hate to tell you though, my mom's first car was a blue '61 tempest.

 

Does anyone have any more info on this car? Pics? Magazine articles?
(I don't know why I couldn't pick up the thumbnails, but it is post # 18, the Mickey Thompson car)

I just bought a 62 Lemans, and I'm building a streetable A/FX type car out of it.
I 've got a bunch of parts I took off it ,and will post a for sale ad.
Also looking for a few items.
Thanks

 

congrats these are neat little cars, I just bought one from an old customer that i built for him 10 yrs ago as a s/p drag car. tube chassis 510 cu.in. chevy and glide full cage and alum interior and morrison front end . im gonna change it up to gasser duty ..will post pics when i get it home next week... good luck however you do yours...

 

These guys can help you a lot. This is the 61-63 Tempest page.
http://forums.performanceyears.com/forums/forumdisplay.php?f=427

I envy you. Back in 62 I bought a Lemans convert. 9yrs10mo and162,820 miles of super service.

About the missing. Pull the dist cap and make sure the weights are free to adv/ret the spark. I used to have to clean and relube the pivots about every 10000 mi.
Also replaced many a vac adv unit. The diapraghm would crack..