View Full Version : Converting Chevy v8 to reverse rotation

Scott Abbott
05-16-2001, 08:32 AM
" I'm considering upgrading the engines in my Chris Craft Commander from 327F's to 350's instead of rebuilding. The Chevrolet "crate" long blocks look appealing ($1400 new, each), but if I buy a pair, one must be converted to reverse rotation. I know I'll need a different cam and the gear drive, as well as dis-assembling the engine to reverse the pistons. My big question is the cam: I would like to match the crate engine cam, but none are available for reverse rotation firing order. I either need to buy a new pair of RH/LH cams, or have one custom ground for the reverse side. Any advice/experience? What about front and rear seals? Does anyone have a source for purchasing these parts (cams, seals, timing gear)? Thanks! "

05-28-2001, 07:55 PM
" Scott, the crate engines you refer to are OK engines for cars but not a great engine for marine use. GM does make a marinized version of the 5.7(350) but it's a bit more pricey. If you just have to use the "target" motor for budgets sake you can do a marine conversion of sorts I suppose. You'll have to change over to brass freeze plugs to start with. If you want to go reverse rotation on one of them, there are several aftermarket cam grinders that offer good cams for both directions of rotation. As far as pistons go.... pistons don't CARE what direction they turn in. If they're in the bore straight, that's all they need. The crate motors that are offered thru GM usually have four bolt mains, steel cranks and a decent set of pistons. Good once again for an automotive application and could be used for a boat(but not advised)Check with a local dealer and find out about the real deal marine stuff. If you want it to last do it right the first time. Good luck, Bill "

01-24-2002, 01:59 PM
You did not state whether you have sterndrives or inboards.If you have inboards just change rotation in trans by reversing the pump.If you have sterndrives find a counter rotator drive.This is how they do it since they stop making counter rotation engines