Land speed / drag racing transmissions

**Jyrki** · 12-26-2008, 03:31 AM

Now I would love to hear what kind of automatic and manual transmissions are all you real racers running. Many of you have been racing your STR-8 cars long before commercial transmission adapters were available. So what have you been using?

**Buick Guy** · 12-29-2008, 06:36 AM

Tremec T-5 5 speed overdrive. Also in the twin turbo car, a 700-4R. Doug

**Jyrki** · 12-30-2008, 02:50 AM

Doug, did you machine the Buick bellhousing to fit the Tremec in, or something else? How about the clutch?

Bendtsen's sells an adapter for the automatics, so that's an easy one, but the manual transmissions are a bit more tricky.

**Buick Guy** · 12-30-2008, 07:02 AM

Jyrki,
Because weight was not an issue on the SaltCat, we built an adapter to mate the 320 straight 8 to a GM bolt pattern, using the plate that comes with the Lakewood scatter shield as a pattern. The tricky part was centering the locating dowels of both the GM pattern and the old straight 8 pattern with the centerline of the crankshaft. Once that is done, then, both surfaces have to be ground parrallel [we had a machine shop handle that part]. As I said, weight was not a problem, and the only material that we had access to was steel, so the plate is shaped like a horseshoe the size of the GM pattern and 1 1/2 inches thick. On the issue of the clutch, we had to have Hayes build us a flywheel for a big block Chevrolet, with a Buick bolt pattern using the Buick bolt and bushing setup. There isn't enough material to re-tap the threads in the shaft. Other options could probably be used, like welding up the holes and re-tapping it to the Chev pattern, or rotating the flywheel and re-tapping it. I think that we decided that one or two holes got too close to each other to do that, though. The clutch is standard Chev. big block, and we used a hydraulic t/o bearing. The pilot bearing on the setup varies depending on which crankshaft you start with. I believe the standard trans. shaft uses a regular pilot bearing, and the Dynoflow shaft needs an adapter built for the bearing to ride in. This was probably one of the most involved parts of building the car. Hope I didn't confuse you . Doug

GH · 12-30-2008, 07:41 AM

On the 1950 Buick salt flat car we used a Muncy 4 speed, stock bellhousing, stock flywheel and purchased a ceramic clutch disc from Boninfante (sp) out of Pennsylvania.

**Jyrki** · 12-30-2008, 11:57 AM

Thanks Doug, for the details. It sounds like you really need to get involved!

Gary, I assume you are using the stock pressure plate with the exotic disc? I have to admit though that I never investigated the possibility to adapt a modern pressure plate.

I went the easy route, like Gary, and machined the Buick bellhousing to accept a Super T-10, which is like a Muncie, but with a different input shaft spline count. You can see pictures here:
http://gamma.nic.fi/~marlin/august01.htm

I'm wondering if anyone has used the Buick trans with an Oldsmobile open tailshaft? I believe they interchange until the early 60's

I've also heard some people adapting a Ford C4 automatic (because it's got a separate bellhousing, thus being easier to adapt?)

GH · 12-31-2008, 08:06 AM

Jyrki, we used the Olds transmission with the open drive line, but we kept chunking out the gears, that's why we went to the Muncy.

**duke** · 01-01-2009, 08:05 AM

We built our own adapter and adapted a powerglide to our straight eight. It work great for drag racing. We used the later aluminum case powerglide. Besides adapting the transmission, we used the same plate as a motor mounting plate for the rear of the engine. Serves two purposes in one. Centering is the most critical part of the manufacturing. But it was done easier with a bare block out of the car and standing it up on end. We milled the center of the crankshaft and built a bushing the correct thickness to fit the torque converter. It was made the correct thickness so we could use converters that were stock lenght and not have to buy more expensive ones.

**36 Century** · 01-02-2009, 08:04 PM

Our Land Speed car uses a 37 trans, converted to open drive line. Transfered to a 9" ford with 2.73/3.08 gears. For Production XX0 puts us at about 150 MPH at 5k RPM with a 26" tire, atleast thats what I remember off of the top of my head. When you machine a interlock into the buick top shift, it is a really strong and reliable transmission.

**39CENT** · 01-02-2009, 08:53 PM

Originally Posted by Jyrki

Thanks Doug, for the details. It sounds like you really need to get involved!

Gary, I assume you are using the stock pressure plate with the exotic disc? I have to admit though that I never investigated the possibility to adapt a modern pressure plate.

I went the easy route, like Gary, and machined the Buick bellhousing to accept a Super T-10, which is like a Muncie, but with a different input shaft spline count. You can see pictures here:
http://gamma.nic.fi/~marlin/august01.htm

I'm wondering if anyone has used the Buick trans with an Oldsmobile open tailshaft? I believe they interchange until the early 60's

I've also heard some people adapting a Ford C4 automatic (because it's got a separate bellhousing, thus being easier to adapt?)

I had an olds trans and the maindrive shaft is too long would need a bellhousing plate or shorten the shaft. but the case is the same as a large series buick strait 8 or V8. you can put the buick gears into the olds open drive case to mate to torq tube or vice versa.