Experts ,
Helping a friend here who bought these cylinders long back as rd250 ones but I doubt ..
Can any body look at these and recollect what model n make these are ?
Pistons are stamped 36102 inside
Cheers
Pravin
Few more
euro model rd250 jugs, coffin tank bike.
Thanks SC .. SO the heads are also different as when I tried to put us model heads they look smaller
So the euro model heads also he needs to get right ?
Cheers
Pravin
He mentioned buying from some German guy so thats kind of confirms ..
from what i understand, yes.
Yep Euro 76-77 (Not 78-79 2R8's) http://erlenbachracing.co/RD250.htm
And Yes you need the heads to match. Nice cylinders. Ed
Thanks Ed !!
Well actually, the US heads will work just fine since the bore centers are the same for both engines and the combustion chamber capacities are pretty close (as I recall). It will just look a little unusual. I think Ed's web site gives the stats on both engines, 2R8's and
US RDs so you can compare them.
Lyn Garland
Hi Lyn ,
Yes they should be fitting ok apart from missing the alignment with the blocks 😃 looking subsized externally ...
Cheers
Pravin
Sure you could run US heads on euro cylinders by why?? Use the euro heads and take advantage of the cooler running they and the larger finned cylinders were designed for... Ed
I've actually gone the other way before and had Scott Clough cut Euro heads (rechamber, center step the heads to center off original US gasket recess and o-ring) to use on a racer that is using US RD250 cylinders just to get a little more cooling..
Ralph also makes his Superior Performance heads for these cylinders I made sure he did his designs so he even covered the Euro 250 cylinders. Ed
And If you race Wossner makes an amazing single ring racing piston for them.
Ed:
Yes, it looks goofy, but part of the original post was questioning the value, or cost, of the DG heads. Also there isn't a plethora of Euro heads available, so it may be awhile for him to get a pair. This will at least will be a stop-gap solution.
Lyn
Thank you all ... I guess he might not invest in heads as firstly budget and secondly hard to get them in India ..
May be he can trade them somewhere ..for 350 ones
Cheers
Pravin
Just thinkin about performance/efficiency Lyn:)
You can still find the euo heads it is a little more work now though. Japan and Australia got "Daytona style" 250's too that would be a rare head but a really good one once properly modified. Ed
Thanks Ed .. good thought .. keep looking for heads ..
Can this top end be installed on our rd350s?
Cheers
Pravin
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.de%2Fulk%2Fitm%2F260944985178
Are these the ones ?
Cheers
Pravin
Yeah those are the heads. Yes RD250 and RD350 bottom ends are identical accept early 73-75 250's had a different primary gear ratio meaning the crank gear and clutch basket gears but you can use either one. But Yamaha went to the "RD350" ratio on all the RDs, LCs and RDs after that.
SUPPOSEDLY THE 250s had slightly shorter cyl studs as well. if so, i've never had it be an issue. just an fyi. no need to swap them.
Good catch Mark, true.