Oil Leak at head gasket

[RPGR90s]

I'm working on a '73 R60 with a very slight oil leak. Original head gaskets, about 36k.

Left cylinder, right at the head/cylinder mating area on the bottom. No oil appearing on the pushrod tubes (where they fit into the cylinder), so I think oil isn't getting past the pressed in area of the tubes.

My question is: Is it possible for the head gasket to leak oil without the engine losing compression? The bike runs like new, so I'm inclined to think that just the seal where the pushrods pass through on the head gasket has failed.

Appreciate your input

[Rob Frankham]

Thos no real reason why an oil leak at the head gasket should necessarily involve compression loss.. it simply means that there is a breakdown in the gasket between the pushrod tubes and open air, not into the combustion chamber. If you're sure the oil is coming from the gasket, then it'll mean replacing the gasket. It's worth bearing in mind, though, that there are also tubes actually in the head visible between the cooling fins. These aren't anywhere near as obvious as the ones between the cylinder casting and the crankcase. It's not unknown for these to rust and spring a leak.

Rob

[RPGR90s]

Thanks Rob,

Here's what I'm looking at. Left cylinder from below.

Left side cylinder R60_5.jpg (218.17 KiB) Viewed 1099 times

[Rob Frankham]

Difficult to say but it does look like the head gasket. Not a massive job to replace...

Rob

[RPGR90s]

Agreed. I'll do the head gasket and check for leaks. Thanks!

[RPGR90s]

Further along this issue, I found a damaged head bolt stud. (left cylinder, upper intake). Would anyone know where I could obtain the jig/tool that is used to assure the hole is drilled and tapped accurately for repair?

[Rob Frankham]

That's a helicoil or insert job complicated by the need to ensure that the oil hole mentioned in my earlier post is kept clear. Probably a job for a machine shop.

Rob

[RPGR90s]

I've decided that I want to use a jig for this job, so if anyone has access to one for rent, I would be very appreciative. Brook Reams mentions that this was available from "Northwoods Airheads" but their website is no longer.

Brook Reams info on performing the repair.
https://brook.reams.me/bmw-motorcycle-r ... d-threads/

[Kurt in S.A.]

I believe I read where Snowbum suggested or considered using an old cylinder as the jig...maybe even only the bottom half that mates up with the engine case. So, would it be possible to use the jug on that side as part of the alignment tool for the repair?

Kurt

[RPGR90s]

I believe you're right Kurt. I do have a machinist buddy that's going to see if he can make a jig, based on my measurements, so hopefully, that will work. But still looking for the official jig for rent if anyone knows a source.