R 60 Heads

[motorhank]

I have an r 60/2.Since the heads were shaved they leak. I think they took off to much metal and did not realize it. Other then shaving the cylinders, any ideas?
Motorhank

[Kurt in S.A.]

How much "off" are the heads? How much would it take to get them planar again?

Seems to me, taking off too much at the heads creates a rise in compression and eventually head-piston-valve clearance issues. Shaving the cylinder base (if that's what you're talking about) or even the top of the cylinder is only going to exacerbate this situation.

There's a 0.5 and a 1.5mm aluminum base gasket that is used on the cylinders. The thicker one is used to help lower compression if needed. I wonder if you could use the thicker base gasket in order to offset the dimensional losses at the head??

Kurt in S.A.

[motorhank]

Hi,I don't know how much was shaved, the head gaskets do not compress properly. I have glued two head gaskets together with high temp. gasket cement giving me a 2.0 thick gasket instead of a 1.0. My machanic says this will not work.
The Heads and engine were re- built about 5,000 miles ago. I have no idea what thickness the base gaskets are.
It's good to know there are 2 thickness of base gaskets.
Any other Ideas?
Thanks, Hank

[Kurt in S.A.]

Are your heads the 1/2" spark plug hole or the 3/4" hole? What year is the bike? In the mid '60s, BMW farmed out head production and the company used an aluminum alloy that didn't stand up well. The result was that the rocker towers would sink into the head, changing valve clearances. After that, BMW changed alloys and increased the spark plug reach to 3/4".

You'd be better off get a set of these heads. BMW stamped the symbol LK for Lange Kerz near the spark plug hole. They become available from time to time. They might be available new, for a price!

Kurt in S.A.