Pat Buckley
GT40s Supporter
Are there any reasons why the Corvair trans can't be used in our cars?
I realize they are only 4 speeds but they are stong.....
I realize they are only 4 speeds but they are stong.....
Corvair trans
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There was a company that made a kit used to mount a SBC midships into a Corvair. As I recall the transmissions wouldn't handle the torque. It's been a long time and I've slept since then, but I think there were some mods that had to be made to the tranny to get it ready for mid-engine placement.
Doug
Doug
Pat
I once worked on a corvair that had been fitted with a Chevy small block. The main problem with the transaxle was that the corvair engine rotates in reverse of other chevy motors necessitating modifications when a V-8 is used. There was an input shaft installed on the opposite end of the one I worked on, with a block-off plate in the original position. The trans held up well, but this put the centerline of the drive shafts about 15" behind the bellhousing moving the motor substantially forward. The car was very tight inside to say the least.
Cheers
Phil
I once worked on a corvair that had been fitted with a Chevy small block. The main problem with the transaxle was that the corvair engine rotates in reverse of other chevy motors necessitating modifications when a V-8 is used. There was an input shaft installed on the opposite end of the one I worked on, with a block-off plate in the original position. The trans held up well, but this put the centerline of the drive shafts about 15" behind the bellhousing moving the motor substantially forward. The car was very tight inside to say the least.
Cheers
Phil
From what I understand, the production Corvair 4 speed is an adaptation (version) of GM's Saginaw cast iron 4 speed gearbox. Not very strong at all.
Best,
S
Best,
S
Pat Buckley
GT40s Supporter
Thanks.
You could use the corvair 'as is' in a GT40 type application with the motor in front of the rear axle,but the Crankshaft would be above the output shafts of the TA and you would be 'driving' on what was previously the 'coast' side of the crownwheel. Being Hypoid it wont really like that and you cannot flip the crownwheel as in P*** etc in order to place the input below the output shafts.
Jac Mac
Jac Mac
There were two companies making adapters to use the Corvair for a mid engine application, M.I.D. and Crown.
M.I.D.s adapter mounted the V8 to the same end of the trans as the Corvair but since the V8 ran reverse the engine and trans had to be swaped 180 degs so the engine was now in the front. This made for a simple install and was shorter but had a couple problems. The first was it used the stock Corvair input shaft that was long/thin and not very strong. The other was it ran the ring gears on the coast side of the gear when driving forward. This developed lots of side loading in the differential. There were reverse rotation gears made that put the gear loading on the correct side of the ring gear but you would have to reverse the engine rotation. Remember that boats with twin engines have one engine that rotates in reverse.
Crown's method mounted the V8 on the front end of the Corvair trans. It used a stock GM bellhousing and a plate that mounted the bellhousing to the Corvair trans. It used a special input and main shaft. The input shaft sure looke alot like the standard Saginaw shaft to me but I havent seen them side by side. This setup rotates the gears in the proper rotation for gear loading. So my recomendation would be to get a Audi trans.... If any of the Corvair parts would fail there might not be any spares...
M.I.D.s adapter mounted the V8 to the same end of the trans as the Corvair but since the V8 ran reverse the engine and trans had to be swaped 180 degs so the engine was now in the front. This made for a simple install and was shorter but had a couple problems. The first was it used the stock Corvair input shaft that was long/thin and not very strong. The other was it ran the ring gears on the coast side of the gear when driving forward. This developed lots of side loading in the differential. There were reverse rotation gears made that put the gear loading on the correct side of the ring gear but you would have to reverse the engine rotation. Remember that boats with twin engines have one engine that rotates in reverse.
Crown's method mounted the V8 on the front end of the Corvair trans. It used a stock GM bellhousing and a plate that mounted the bellhousing to the Corvair trans. It used a special input and main shaft. The input shaft sure looke alot like the standard Saginaw shaft to me but I havent seen them side by side. This setup rotates the gears in the proper rotation for gear loading. So my recomendation would be to get a Audi trans.... If any of the Corvair parts would fail there might not be any spares...
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Both are out of business. Clarks Corvair parts bought the rights for these. I think he markets some parts. The corvair transaxle that is the strongest is the 66 and newer. It has a Saginaw transmission that is very similar to the Saginaw transmission used in the other GM cars. However, the weak part of this is the differential. It is very small and doesn't handle V8 torque very well. The spider gears break and the case breaks. It's really not a good choise for a v8. I used to be into Corvairs. The reverse kits were bad news. Mid Engineering and Kelmark made kits to turn the transaxle around and spin it backwards. This puts all of the torque on the coast side of the gears. The Crown kit used the late saginaw transaxle and just mounted the engine in front of the transaxle. This spins everything the correct direction. The problem with this kit is that the bellhousing connection to the transmission has two bolts on each side at the bottom. You end up having a problem with the top of the bellhousing splitting from the transmission case bending everything. Many people tried to fix this over the years without much luck. If you check out Kennedy Engineering's web site he describes the strength of this. It isnt good. You're probably better off with a Porsche 901 than the Corvair.
"From what I understand, the production Corvair 4 speed is an adaptation (version) of GM's Saginaw cast iron 4 speed gearbox. Not very strong at all." Compared to what?? Unless you specified when ordering, or had a big block, high HP small block or a 'Vette - you got a saginaw. A 4000 lb Impala SS 300hp 350 would have come with a saginaw tranny. 380 ft. lbs. of torque versus 4000 lbs. of mass sounds like recipe for breakage, but they worked fine. The weak point in a Corvair transaxle is the 6 1/2" ring gear and the spider gear housing. There are aftermarket parts available to make them stronger, but you wind up with a 145lb. monster of questionable strength....IMHO. Parts supply has dried up, and in Crown form the legroom is comprimised. There is an interesting thread on the Corvair Center forum about a fellow who has adapted a Saginaw tranny to a C5 Corvette diff. No worries about strength! They use the Saginaw because it is the only one I know of with the reverse gear in the main tranny housing. You can remove the tail housing and still have all the moving parts intact. There are 4 sets of ratios in the Saginaw. From a 2.54 to 3.50 first gear. I'm going to run the C5 setup in my Corv-8 complete with subframe and suspension pieces for now, but plan on an 01E in the future. Cheers, Dave
Hi Dave,
I agree that the Saginaw 4spd is not as wimpy as some might believe - it just doesn't have the following of the Muncie and Borg Warner 4 speeds.
On your note regarding integral reverse gears.
Actually the venerable Ford Top-Loader 4 speed and the Chrysler New Process "A" Series 4 speeds (for both A and B body cars) both have integral reverse gears to the main housing - much like the Saginaw. And like the Saginaw - they're both in very heavy cast iron cases.. Both the Ford and Chrysler transmissions are known for their strength.
It would be interesting to see a kit produced that would mate any of these three grearboxes to a C5 Corvette differential..
Thanks for setting me straight, Randy. Any idea what the output shaft dia. and spline count of those two trannys are? I would much rather have a top loader. I was going to contact the fellow who did the conversion to see if he was going to make and sell them.Picasa Web Albums - Michael - Saginaw to C-5 This link should take you to his site. Cheers, Dave
Pat,
I came across this in Craigslist - a new crown Corvair Transaxle in the DC area - no relations to me!
John
CROWN V-8 Corvair Kit
epper:
A friend has one in a smallblock powered Manta, the input shaft is long and spindly and also the box seems to be pushing itself apart(thrust bearing surface not sufficient?) does not hold up very well at all and has had extensive beef up and internal modification.
Unfortunately to change it out will require a complete redo of the back of the car.
Unfortunately to change it out will require a complete redo of the back of the car.
Hi Dave - Neat pics!!! I'm afraid that I can't help you on the Toploader and New Process shaft information as I don't have any in the shop right now.
Matter of fact all I have is a couple of Muncies and a ((gulp)) Saginaw!
Terry Oxandale
Skinny Man
The Manta Mirage project I'm working on had the Corvair transaxle behind a SBC (both have been replace by other makes). The reliability behind these were fine for the street, but marginal under any high torque application. I'd be willing to compare the reliability to the Audi transaxle in term of strength.
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