Reverse drivetrain direction
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Reverse drivetrain direction A friend of mine is trying to put a vette motor/transaxle in a corvair.
It occured to him that if the motor/transaxle are facing backwards he will be able to go very fast backwards but not so fast forwards. How would you change the direction of the drivetrain. I don't know if reversing the firing order would work because it's computer controlled car. Could you change the coil packs around?
Ben
It occured to him that if the motor/transaxle are facing backwards he will be able to go very fast backwards but not so fast forwards. How would you change the direction of the drivetrain. I don't know if reversing the firing order would work because it's computer controlled car. Could you change the coil packs around?
Ben
Maybe dumb comment, and don't know if it's even possible, but could you flip the ring gear to the opposite side of the differential (basically turn the posi around the other way)? Probably wouldn't fit... but that would reverse the direction of rotation on the rear wheels.
Besides the ignition timing, you would have to consider the valve event timing too. (that's if the pcm would even handle a reluctor wheel turning backwards).
And reversing the rotation of the water pump, alternator, etc.
Flipping the diff over sounds like the easiest way.
And reversing the rotation of the water pump, alternator, etc.
Flipping the diff over sounds like the easiest way.
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From: Upstate NY
Originally Posted by Bens3rdgen
A friend of mine is trying to put a vette motor/transaxle in a corvair.
It occured to him that if the motor/transaxle are facing backwards he will be able to go very fast backwards but not so fast forwards. How would you change the direction of the drivetrain. I don't know if reversing the firing order would work because it's computer controlled car. Could you change the coil packs around?
Ben
It occured to him that if the motor/transaxle are facing backwards he will be able to go very fast backwards but not so fast forwards. How would you change the direction of the drivetrain. I don't know if reversing the firing order would work because it's computer controlled car. Could you change the coil packs around?
Ben
Reversing an LS1 is a challenge. I don't think reverse rotaton cam cores are available as they are for SBC and BBC engines used in boats and sprint cars.
FWIW, if you put the C5 engine/transaxle in backwards even with the engine directly coupled to the transaxle, the engine would be almost completely outside the car. You'd need wheelie bars just to support it.
A possible conversion is to use an old THM 425 transaxle from early Olds Toronado. It's strong enough, as basically it's a reverse-rotation THM 400. It puts the engine in the rear seat area which isn't all bad. CG is a little high but nothing a roof airscoop won't solve.
There were SBC V8 conversion kits which used the Corvair transaxle, but it's not very strong. Crown made the kits, I believe.
FWIW, the original VW Beetle swing axle transaxles could easily be reversed by flipping the ring gear, but VW designed them that way. Any old VW geezers here WHO remember why the ring gear could be swapped? An old Hippie might know why.
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Originally Posted by Old SStroker
... Any old VW geezers here WHO remember why the ring gear could be swapped? An old Hippie might know why.
<Ahem>: That would be to permit the VW van to enjoy 4 forward gears and only one for reverse, since it used a single drop gear at the rear hubs to raise the numerical final drive ratio and improve ground clearance. Thus its axle shafts turned backwards as it drove forwards.
Many a VW transmission swapper learned of this idiosyncrasy the hard way...
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From: Upstate NY
Originally Posted by MadBill
Did someone call for a hippy/geezer?
<Ahem>: That would be to permit the VW van to enjoy 4 forward gears and only one for reverse, since it used a single drop gear at the rear hubs to raise the numerical final drive ratio and improve ground clearance. Thus its axle shafts turned backwards as it drove forwards.
Many a VW transmission swapper learned of this idiosyncrasy the hard way...
<Ahem>: That would be to permit the VW van to enjoy 4 forward gears and only one for reverse, since it used a single drop gear at the rear hubs to raise the numerical final drive ratio and improve ground clearance. Thus its axle shafts turned backwards as it drove forwards.
Many a VW transmission swapper learned of this idiosyncrasy the hard way...
It made it easy to swap a Corvair into a V-bub based dune buggy also. Germans made their engine run backward...or was that the Corvair?
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Flipping the gear also beat hanging the '61 Buick aluminum V-8 out the back of my '52 split window Beetle. 
PS: It turns out Porsche trannys of the era didn't share this capability. (Don't ask me how I know this.
)
PS: It turns out Porsche trannys of the era didn't share this capability. (Don't ask me how I know this.
) 
Why don't you put it in the front?
A local guy has an L98 in his 69 Corvair on a Monte Carlo chasis.
He is in the process of making it into an LS1 car. He also has a 12 bolt in it.
A local guy has an L98 in his 69 Corvair on a Monte Carlo chasis.
He is in the process of making it into an LS1 car. He also has a 12 bolt in it.
A possible conversion is to use an old THM 425 transaxle from early Olds Toronado. It's strong enough, as basically it's a reverse-rotation THM 400. It puts the engine in the rear seat area which isn't all bad. CG is a little high but nothing a roof airscoop won't solve.
Bill
Reverse rotation engines are quite common in some dirt track applications where the rotation of the motor helps pin the LR tire on the surface..I have a friend who builds these thigs he shop in called "Reverse Racing" A special crank ,cam and oil system is required as well as a special ring and pinion for a quick change or 9inch which isnt that hard to come buy..however for a C5 I'd be willing to bet your screwed and as far as running helical cut trans gears you might run into some issues there as well straight cut gears wouldnt be an issue...
i remember this one...the corvair engine sits with the front of the old engine towards the rear of the car. i.e. a rear engine rwd car. when they put the sbcs in them the sbc faces the front...and so the reverse spin of the motor doesnt matter all the while converting the car to a tru mid engine setup...at least thats what i remember. read up on the corvair v8 swap i think it says it somewhere at the site where they sell the kits. im not sure what mods youd have to do to the body/chassis but it would be a bad ************ in the end with the engine in the middle of the car. 
[QUOTE=00transamnh]Ski doo snowmobiles get their engines to stop and rotate in the opposite direction in order to go in reverseQUOTE]
those are two stroke engines no valve train to deal with
those are two stroke engines no valve train to deal with