I'm starting the build up for the 260. I'm starting w/ "seasoned" 350 cores, I'll have Paul Pfaff build up the shortblocks...either 383's or 406's.

But the real question is does anyone know the true differences between a standard rotation crank and a reverse rotation?


I did some looking and found only a few hits. I've read that the difference is the crank has some pressed in directional wipe marks embossed in the main seal area, that have to be polished out or...the motor will be "wiping" the oil out of the engine....

What do you guys think.....Also Dave....are you running stock 350's w/ the exception of your heads....?

I wouldn't bother with it. most reverse rotation motors were used in straight inboards not i/o's.In sterndrives the reversion is usually done in the drives.If you have alpha drives you need a special drive,if bravos you basically run one drive in reverse with a reverse rotation prop.

I'll be running Konrad 540's...I don't think there reversable.

I don't know the exact difference (if any) in a reverse rotation crankshaft, but I do know that the rear main seal is different. Alpha and TRS drives are different for standard and reverse rotation applications.

It would be best to check with Konrad,I can't remember even seeing a twin with trs's that had a reverse rotation engine.