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Re: exotic cylinder conversion mystery ?
Posted: Sat Oct 24, 2015 12:40 pm
by holty
hi chez,
yes can see the pics, the transfers are a bit smaller than mine, the studs on yours are standard lammy position, all 4 of my studs are a bigger distance appart, and symetrical,i am still guessing at which cylinder has been used, its not a bultaco, i dont think its kx either.

Re: exotic cylinder conversion mystery ?
Posted: Sun Oct 25, 2015 7:16 pm
by shocky
There is also a kdx 200 and mtx 200 plus may variants from other countries im sure the kdx originally used 4 studs and 5 head bolts then went 5 studs 6 bolts and so maybe the 75 mm spigot is about right for a 67mm piston ? And 80mm for the 70mm piston on the 250, s id look at trial/ trail bikes from about 10 to 20 years ago , the reson I say that as most later cylinders seen to have a 3rd port at the top , im sure all the Japanese manufacturers had a 200 of some type but they might not be that prevalent in the uk so you might have to check out the world wide options and variants , is there any evidence of water cooling ,
Re: exotic cylinder conversion mystery ?
Posted: Sun Oct 25, 2015 8:32 pm
by holty
thanks for those suggestions, i cant say if it was water or air cooled, its just a bare engine case, not even a mag flange, im sure someone must have seen it before, or worked on it at some point.
holty
Re: exotic cylinder conversion mystery ?
Posted: Mon Oct 26, 2015 7:59 pm
by holty
i thought i had found a cylinder to fit, a rd 350lc barrel, but the studs are just slightly wrong, any more suggestions anyone ?
Re: exotic cylinder conversion mystery ?
Posted: Mon Oct 26, 2015 11:22 pm
by Muppet
suzuki rm?
Re: exotic cylinder conversion mystery ?
Posted: Wed Nov 04, 2015 11:09 am
by holty
ive looked at lots of cylinders, i realy would prefer liquid cooled, and just wondered if anyone had ever fitted a gasgas 250 cylinder on a lambretta, looks like they use a 60mm stroke which would make port timings suitable depending on rod length and compression height of the piston, i know i will have to alter the casing to suit the shape and height of the barrel, any thought folks?
holty
Re: exotic cylinder conversion mystery ?
Posted: Wed Nov 04, 2015 10:49 pm
by holty

this type
Re: exotic cylinder conversion mystery ?
Posted: Wed Nov 04, 2015 11:34 pm
by gpts1
holty wrote:ive looked at lots of cylinders, i realy would prefer liquid cooled, and just wondered if anyone had ever fitted a gasgas 250 cylinder on a lambretta, looks like they use a 60mm stroke which would make port timings suitable depending on rod length and compression height of the piston, i know i will have to alter the casing to suit the shape and height of the barrel, any thought folks?
holty
KTM 200 use a use 60mm stroke, Im currently trying to hunt one down for my sprinter project.
Re: exotic cylinder conversion mystery ?
Posted: Mon Jan 04, 2016 12:06 pm
by elb1
Don't know if this will help but there is a guy on face book called Bob monkhouse on lambretta racing page who is making his own barrels called challenger 2 he is doing water cooled versions as well. Be interesting to see how they turn out when they're finished.
Re: exotic cylinder conversion mystery ?
Posted: Mon Jan 04, 2016 2:39 pm
by eden
holty wrote:ive looked at lots of cylinders, i realy would prefer liquid cooled, and just wondered if anyone had ever fitted a gasgas 250 cylinder on a lambretta, looks like they use a 60mm stroke which would make port timings suitable depending on rod length and compression height of the piston, i know i will have to alter the casing to suit the shape and height of the barrel, any thought folks?
holty
Mate of ours has transplanted a gas gas engine into a lambretta frame and put it on the dyno a few weeks ago... 10 bhp but s**t loads of torque.