hibby

Well just got back from running the blackjack with the m-5 and stroker crank and not very impressed low speed was 44mph top speed was 46mph with 15160 rpm. I trried tunning the carb and made 5-6 different passes. Then I switched that motor out and put my other stock m-5 motor in with everything the same including carb but no stroker crank and my low speed was 48.3mph top speed was 49.4 with 16280 rpm. My best speed to date with the stock m-5 motor was 49.8mph last fall. My squish on the stroker crank motor with one .015 stock gasket was .008 so we put 2 gaskets on which put us around .020-.022 the piston ring was still slightly above the nub in on the intake. Maybe it needs some porting done, it just didn't have any torque like the stock motor, I don't know but I think Im going to put back the stock crank and swap out the stock 0 band pipe and buy a 2" band pipe. The proof is in the pudding two Identical motors one with the stroker and one without, #'s don't lie!! Not to say a stoker crank doesn't help but Im not an engine builder and interested in doing any porting etc. just looking for some easy bolt on things to help performance and think the pipe is the way to go. Hope this helps anyone else who wanted some info on the stroker crank. Hibby

Dockman

Need to get the rpm's up on that stroker. My BJ55 with a stroker and modded RCMK cylinder ran 55.6 in the 18000 rpm range. The weather was alot cooler then it is now.

hibby

Thats the whole thing the m-5 motor couldn't get the rpm's up with the stroker crank in it, it might help in a fully modded motor but the money spent on it would have been better used on a pipe which is my next thing Im going to do. I was really pleased with my speed yesterday in the stock m-5 motor with the humid and hot temperatures and calm water at the pond ran 48-49 consistently. Hibby

Dockman

I agree that 48 - 49 with a m5 is awesome. You should get a stock Zen cylinder and try doing your own porting. If you ruin it not out much money? MGB website has a good article on porting a Zen.

hibby

I have another stock jug but not really interested in porting myself, just looking for some bolt on stuff to gain alittle performance and hope the pipe might get me another couple mph and hit the 50mph. Will keep you posted if I get that pipe and what it runs. Can't wait till we get some cooler weather here, the humidity and heat has been one of worst on record here this year. Thanks for calling me last week and hope you get your blackjack back up in the mid 50's again. Dave

Dockman

I always said I would not do my own modds either. Last winter I done some reading and decided to give it a try. I have not got to the inside of a cylinder yet but I do plan doing one this fall.