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Old 02-01-2010, 12:25 AM   #6
bill dedman
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Location: Conway, AR
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Default Re: Pontiac SOHC 6 Stockers ?

Drooze,

Beginning in 1961 (or, was it 1960? My recollection is so fuzzy... sorry), Tempests were built with a Corvair-like transaxle that had swing axles like the Corvairs of the day did. The power was transmitted from the crankshaft in the front of the car, to the transaxle, in the rear of the car, by what most laymen called a "rope." a flexible piece of somethingorother that was able to bend a certain amount to "sowbelly" under the floorpan, in the absence of a conventional driveshaft tunnel. The cars with this system (all Tempests through 1963) had the clutch, or converter,(if an automatic) attached to the front of the transaxle case, in the back of the car (I'm not making this up....)

The transaxle unit was a Corvair-type unit, with swing axles. Unsafe at any speed.... LOL!

Swing axles are different from IRS in that an IRS system has two U-Joints on each axle, so that camber is not necessarily relative to the axle's position in its travel up and down. Swing axless create a situation wherein, the attached wheel's camber is a slave to the vertical position of the wheel in its travel, because it's "hinged" at the axle's end (at the center of the car.) This creates overt and potentially-dangerous changes in camber as the wheel travels up and down due to road irregularities, etc... Not good. Additionally, if the axle snaps, the wheel goes completly awry because the axle is one of the locating components.. sort of triangulating the location process. Should it break, the wheel can (and, will) fold up under the car like a landing gear on an airplane that has "fold-up" landing gear.

Corvettes never had swing axles; they went directly from the live axle 1962 models to the IRS, in 1963.

But in the recent past, the Corvette's drivetrain configuration has been redesigned, and has moved the transmission to the area just in front of the pinion gear, and has incorporated the clutch (or, converter,) the transmission case, and the differential housing all in one unit... a "transaxle" that incorporates an IRS system.

All that gee-whiz wizardry apparently doesn't do much for the drag racing capabilities of the car, for whatever reason, so a Stock Eliminator car was approved by NHRA, that allowed moving the transmission back to the front location, attached to the engine, and the transaxle care and its attendant IRS components were changed to a live axle (probably a 12-bolt housing andthe necessary gears.)

No more transaxle... just old-fashioned drivetrain pieces.


I am wondering whether the '63 Tempest, which has a transaxle AND swing axles, might not be approved by NHRA, since the Corvette got approval for such a change.

Am I nuts for thinking this might be feasible?

If they (NHRA) fail to approve it, after giving the late-model Corvettes the nod to make this switch, I'd sure like to be there to hear the rationalizations flow, as they squirm like a worm on a hot griddle, trying to justify why that what's good for the goose is NOT good for the gander, in this case.
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Last edited by bill dedman; 02-01-2010 at 01:02 AM.
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