January 13, 200818 yr What is the maximum engine capacity that can be achieved on a 200(late motor) Cub without increasing the stroke?Anyone have any comments on the no doubt numerous ways of doing it?Cheers,ALT.
January 13, 200818 yr No idea, I'm not an engineer, just call it a B40 and then you can have 343cc as standard! ....besides Cubs are on the way out as far as Scotlands' concerned, just toooooooo many entering! Big John
January 13, 200818 yr Author Big John,I already own a B40 and I don't plan to enter the 2 day on a cheat Cub,, even if it appears to look "right".Cheat bikes are killing pre-65 trials(my own B40 included),so I can sympathise with your views but can someone answer my question?
January 13, 200818 yr From memory i think it's 230 cc and i think you can use a Triumph Trident piston but dont quote me on that. Best bet is to ask Tricky Micky or ring Alan Whitton as he seems to be involced at some point with most of the more cmpetitive Cubs about.
January 13, 200818 yr Hi Guy's Hi ALT. I think OTF, is right I have all the info somewhere, but I will have to look it up, but I think it's about 230cc. But I have been told not to use any part made in the far east. give me time to look it up and I will get back to you. Regards Charlie.
January 14, 200818 yr Author OK,thanks Charlie.By the way,are you a pseudonym (dont take it the wrong way!)?Reason for asking is that I don't live a million miles from you and have been riding trials for 31 years,so there's a pretty good chance that I should know you!
January 14, 200818 yr Hi Guy's. Hi ALT, Yes some of me is that big word that you said. Back to topic, 67 mm is the size to take the barrel out to.( More to get liner to fit) But be WARNED, make sure you have a barrel to play with as well as the one from the motor. And this is what I have sort of researched for my next project. A liner for a Triumph Trident is the thing to use so i'm told, along with a piston for the same.(if not using an alloy barrel). The cylinder head will have to be machined to fit,and a new route found for the oil from the rocker cover to the crankcases. Down the studs so i'm told. The mouth of the case's will also have to be taken out for the new liner to fit, And i'm sure that there will be load's of problems that will crop up. But Its worth a go as a challenge. And It's only worth doing on a late motor. with two roller mains. You can e-mail me if you like, Its on my Profile. Good luck with the project: Regards Charlie. Edited January 14, 200818 yr by charlie prescott
January 15, 200818 yr You'd probably want to start with an alloy barrel as it will run cooler, then I think it you can out to 220/230 leaving the crank alone - think it might be a Kawasaki piston. Crank mouths have to be opened out to fit the bigger dia. liner. So its a full strip down etc. I costed it out many months ago and it didn't work in for me, so have stuck with a 199. I think DaveD444 sold a complete engine a while back on ebay, he might be able to help out on the spec. Edited January 15, 200818 yr by Subira
January 18, 200818 yr Hi - Alan Whitton did my engine for me to 230cc - hes the man to speak to on this - it certainly worked beter on the standard stroke at 230 cc as it still revved well unlike the 250cc conversions that I tried when deciding which way to go.
November 22, 201411 yr there is a conversion piston and cylinder 250 cc on short stroke and 270 on the long stroke that seems to work fine mine is 230 short stroke
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.