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cranks which one ???

Posted: Mon Oct 05, 2009 9:00 pm
by poppygun
hi all have just got an rt220 and a 35mm mikuni all from mb
probably going to also buy an alpha crank but do not understand
about stroke con rod length and how this will affect my engine
carrateristics i think mb said when buying my rt220 kit
that it did not make a lot of difference on his dyno but i was on a bad mobile line
so could of got it all wrong. also any thoughts on gearing have a 69 gp 200
thanks poppygun

Re: cranks which one ???

Posted: Mon Oct 05, 2009 9:10 pm
by 22/2
Have a little look at this to get you started, but I would try to talk to someone reputable again (MB as your getting everything else from them) if your not sure. The kit is probably set up for a 58 stroke but you can put in more if you want, say a 60mm and up the cc but it may affect your timings, this could be made better with some fettling. Ask yourself what you want to achieve from the engine?, are you building it yourself?

http://www.scooterhelp.com/tuning/defs.stroke.html

Rich

Re: cranks which one ???

Posted: Mon Oct 05, 2009 9:18 pm
by sydduckett
What did that little lot set you back...?... :o

Re: cranks which one ???

Posted: Mon Oct 05, 2009 9:40 pm
by poppygun
thanks rich good info. probably just go 4 a 58mm x110 con rod will get a local dealer to build it ie jahspeed or jb tuning
to build it and dyno it when all the bits are in stock
as to sydduckett ?
kit+ 35mm mikumi+manifold + manifold opened and flowed+carriage=£948.88 alot of hard earned cash
better be good?
thanks poppygun

Re: cranks which one ???

Posted: Mon Oct 05, 2009 9:51 pm
by sydduckett
I take my hat off to you sir. Will be going down to Jb on sat for them to balance my crank and grind out the back of the sproket. Hoping to get over to jarspeed for a new exhaust at end of the year pennies permitting.... :D

Long shlep for you though, gotta love that A12

sef

Re: cranks which one ???

Posted: Mon Oct 05, 2009 10:15 pm
by soulsurfer
Personally, I'd give MB another call, maybe on a land line, and have a really good chat about your crank options before making any rash or ill-informed decisions, after all they'll know what's best for this kit and you wouldn't want to undo the development work that's already gone into this kit without speaking to the man that developed it, would you? I know I would after spending the best part of a grand for a cylinder kit with them :?

Re: cranks which one ???

Posted: Tue Oct 06, 2009 11:26 am
by lockman69
JB Tuning super Corsa crank 60x110, £100 cheaper than the race tour crank, speak to John @JB he knows his stuff.

Re: cranks which one ???

Posted: Tue Oct 06, 2009 9:23 pm
by darren112
have a alpha 58*110 sat on the shelf couldnt get my squish clearances .one hell of a bit of kit :)

Re: cranks which one ???

Posted: Tue Oct 06, 2009 9:29 pm
by J1MS
soulsurfer wrote:Personally, I'd give MB another call, maybe on a land line, and have a really good chat about your crank options before making any rash or ill-informed decisions, after all they'll know what's best for this kit and you wouldn't want to undo the development work that's already gone into this kit without speaking to the man that developed it, would you? I know I would after spending the best part of a grand for a cylinder kit with them :?
Wot he said....

Re: cranks which one ???

Posted: Wed Oct 07, 2009 6:47 pm
by poppygun
just got a alpha 60mm x110 con rod they said more torque than a 58mm one.
now the pipe dev tour or not ? still not in stock yet
thanks poppygun