crankcase question

chevyiron420 Wed May 20, 2015 12:54 am

I have two crankcases to choose from for my blackwidow repair project. One was a car engine with the larger crank and spline. It has been fitted with a bored oversize brass drive hub. The other is a standard model with an aluminium hex drive hub. The car engine feels like it has slightly more play in the crank fit. Anyway which case would you use and why? Do the car cases have any issues?

I tested both engines with a unknown red backplate with the wire E clip retainer and a floppy drive reed, 5 1/2x3 prop, 20% fuel, Tee Dee head with 2 shims. The car engine made 15000 rpm and the other went 15500. The cylinder could have made some difference. Once I make my choice on the engine its back to carb repair on the busted plastic backplate.
Phil

Mark Boesen Wed May 20, 2015 4:43 am

i would use the one you like best, cases will not have that much of an effect on performance like the piston/cylinder fit or compression ratio would. I'd made sure there's not any play in the fit (maybe lean towards the non-car case) polish the crank, maybe lighten it up and off you go.

crankcase question

crankcase question

Re: crankcase question