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Re: Crank Identity

Posted: Sat Feb 20, 2016 9:40 pm
by philthehill
Les
If you are going to put a Shorrock's supercharger on that engine I personally would not use the 1275cc Marina/Ital crankshaft and rods but fit a 1275cc Midget crankshaft and rods.
The 1275cc Midget crankshaft is a much better crankshaft and stronger too. The Midget rods are stronger and you can even fit the early 1275cc Cooper S rods in EN24V if so desired.
The 1275cc Midget crank will fit that 'A' Plus block without any modification.
The Midget flywheel will bolt straight on and you will have no disintegration worries.
Reface and index drill the 1275cc Midget flywheel and you can have a 7 1/2" clutch to transmit the power.
Phil

Re: Crank Identity

Posted: Sat Feb 20, 2016 9:49 pm
by bmcecosse
A supercharger puts less strain on the crank and rods than more normal 'full race' modifications - since generally super high revs are not used. I believe the Marina crank and rods will be fine with a supercharger (but do use good quality bearing shells) - the Mini lads do it all the time since genuine old Cooper S cranks are like hen's teeth - and they have no problems with either supercharger or turbo... It's revs that break cranks - not 'push' from the pistons.

Re: Crank Identity

Posted: Sat Feb 20, 2016 9:58 pm
by les
What you say is no doubt true Phil but doubt i'll run the supercharger for too long, and the crank I have is standard and too good to just put aside. I will of course keep a look out but don't want to get deeper and deeper in this rebuild, I'm not starting this until the summer so who knows what might turn up by then. :D At least a low compression engine will suit better! I was not expecting to see that number crop up so thanks.

Re: Crank Identity

Posted: Sat Feb 20, 2016 10:01 pm
by les
Things get out of sequence when posting at the same time, not ignoring you Roy!