A Tempest on the Track (Part 2)

Continuing yesterday’s dream, I’ll now pick which Tempest from the first three years I’d have and follow up with how I’d make it track-worthy.


Credit: Thomas A. DeMauro / High Performance Pontiac / Hot Rod

To me all three years of the first-gen Tempest (also known as GM’s Y-platform) have attractive styling details, but I’d prefer a ’61 for a few reasons: the split grill, the ribs down the center of the hood; the side “swoop”; the lack of rear fender fins; and it’s from my birth year. Honestly, though, I’d try to find the most rust-free example from any of the years.

On to the modifications. At the end of the last post, I shared that the stock manual drivetrain will handle the 352 foot-pounds that the 326 V8 was rated for. I also mentioned the ideal 50/50 weight distribution of the car, however, that was with the base 196 cubic inch Trophy 4. Bumping up to the V8 brought with it an additional 260 pounds (roughly 650 pounds versus 390 pounds) all on top of the front wheels. So I need a lightweight engine that puts out around 350 ft-lbs. Lo-and-behold the LS1 engine weighs roughly 390 pounds, and, depending on what vehicle it came in, puts out anywhere between 335 and 365 ft-lbs. So an LS1 it is. Hopefully, a bellhousing adapter and a custom coupler to mate the crankshaft to the torque shaft don’t add too much weight. I’m going to have to use the torque shaft as-is, so the engine mounting location may have to change, but this can be accommodated with the required custom engine mounts.



Okay, the GO has been dealt with; let’s turn our attention to the STOP. From what I’ve seen in photos and read on the web, Pontiac used Corvair-style car half-shafts to spin the rear wheels. The small nine inch diameter drums only accommodated one and three-quarter inch wide shoes. An upgrade the Corvair folks make to their first-gen cars is to convert to truck half-shafts and drums. This gives a two inch increase in brake shoe diameter and a quarter inch more width. I’m not sure if this is an option for the Tempest. With the swing axle rear suspension (more on this later), I’m very limited on swapping in disc brakes. There is a Corvair guy that’s making rear disc setups for the Corvair car, and the images I’ve seen of the Tempest brake setup look a LOT like a Corvairs, so maybe this is the way to go. The fronts should easily accept a disc brake swap, so I’m not worried about that. Stock wheels would not fit over the calipers, but the stock stamped steel wheels were going to be swapped out for something larger and lighter anyway. I’ll address that in my next post.

The other end of the braking system is the master cylinder. Back in the day, you could only get a single reservoir master cylinder. I’ve done the easy conversion from single to dual on Corvairs, so I’d do the same on the Tempest. Regarding power brakes, I don’t think it was available. The same was true for the Corvair, so I’m not surprised. The light weight wouldn’t really necessitate the added braking pressure.

That’s enough for today. The next post, where I talk about suspension and wheel changes, may not appear until Monday.

I’d love some feedback on what I’m dreaming about here, so feel free to comment.