TheSamba.com :: View topic - Rod to cam clearance, reversing engine rotation?

Mon Dec 12, 2011 10:52 pm

They used to do this to Chevy v8's to gain clearance in the engine (and for boats). You can reverse the rotation of a corvair to use it in a VW. Has anybody tried this with a VW before. Just wondering if this would gain some clearance for the rod to cam on those high lift stroker engines.

Sat Dec 17, 2011 9:36 pm

I dont see how it changes any clearances at all.as for boats it was becaust it was easyer to spin the mootor backwards than run it through a reverser witch eats up power.it was mostly just on twin screw boats so you could steer. yes some race cars did it, it was outlawed.it helped you around the corrners(circle track stuff)

Sat Dec 17, 2011 10:06 pm

mark tucker wrote: I dont see how it changes any clearances at all.

The way it was explained to me is that if your clearance issue is from rod cap to cam lobe tip(like it is on a 36hp) when you move that cam lobe to a different location it might work out to where you don't have that interference issue.

Mon Dec 19, 2011 2:45 pm

I'm not sure, but after you have a custom 'reverse rotation cam' ground, assuming the cam lobes interfere less with the rod caps, you could flip the ring gear over to the other side, but then what?

What do you do about an oil pump that now turns the wrong direction?
Distributor drive trying to climb out of the case (I think)?

Tue Dec 20, 2011 12:49 pm

Tom Simon wrote: I'm not sure, but after you have a custom 'reverse rotation cam' ground, assuming the cam lobes interfere less with the rod caps, you could flip the ring gear over to the other side, but then what?

What do you do about an oil pump that now turns the wrong direction?
Distributor drive trying to climb out of the case (I think)? add ideler gear to right the cam& it will now turn the same direction as the crank, but I think if I had issues with that I would 1 use a different rod combo,2 use a lower lift cam,3 use higher ratio rockers.5 if the stroke is too long, lower the cam in the case& use different gears.there is a way around everything execpt for deathintexas.