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Sleeving of cylinder

Moderators: Curt!, Pa

Post Thu Jan 03, 2008 6:32 am

Posts: 11
Location: Sweden
Have sleeved cylinders on my U 70".
My problem has been with the material of the sleeves.

After one seasons with a tired bike I decided to go for "high compression" heads and when the old cast iron heads removed I noticed bad lines in the sleeves.
I bored the sleeves from standard to .020" and mounted NOS rings in after market pistons.
(...with alloy heads and fresh cylinders the bike was a rocket...)

The "standard" bore pistons were also aftermarket with thin hardened aftermarket rings....the sleeves looked like when you are really overheating the rings (glowing rings).
But this had not been the case.

My theory is that my sleeves are in some hardened steel that must be used with some old type of non hardened rings.
The situation is today OK but if I have had a chanse to drive with 0.050-0.060 bore without sleeves this would have been much better according to my knowledge both from a cooling perspective and from a material perspective.

My bike has runed 5000Km (3100 Miles) during 2007 and the cross marks after the grinding stones are almost gone..

Sorry for my english..

//Hoit

Post Thu Jan 03, 2008 12:04 pm

Posts: 1646
I like the idea of a U flathead rocket....

actually that's a good point, about the sleeve material versus the liner I mean.
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Fri Jan 25, 2008 1:59 am

Posts: 90
Location: Norway
Okei, I have done som e thinking. I will try to bore the front cylinder and see if it cleans up at a resonable bore size. I then have to live with different bore size on the 2 cylinders.

Have anyone tried to use VW bug pistons in HD?
Torstein

Post Fri Jan 25, 2008 3:23 am

Posts: 1646
no problem having different overbore sizes on a v-twin engine
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Fri Jan 25, 2008 11:08 am

Posts: 2685
Location: Los Angeles, CA
Corvair pistons work in UL cylinders.

Post Sun Jun 15, 2008 1:55 am

Posts: 90
Location: Norway
My bike is now running very happily! Because of the possible trubles when you sleeve, I choosed to bore the front cylinder to +040. The bore senter was shiftes to the side where the deepest damage where. It did not clean up totaly, a very small "hole" is remaining with diameter less than the height of the piston ring. I'm going to take of the cylinder head after a few miles to inspect. So far so good. The rare cylinder remained +020 as this bore was OK!

Thanks for the response on this!
Torstein

Post Sun Jun 15, 2008 4:16 am

Posts: 1646
strictly speaking, the maths of the balancing is wrong with odd sizes rebores; in practice you will never know the difference
Shoot, a man could have a good weekend in Dallas with all that stuff...

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