46 UL Badly pitted cylinder head gasket surface

[sirhrmechanic]

Bob:

Good thought, but those are aluminum heads. Silver wouldn't stick and the heat would be enough to warp them if you tried to weld.

We've done some interesting repairs to D-series Phantom III heads using sleeves, machined and pinned-in fillers, etc. Sometimes you can also use the Irontite Plugs that I did some photos of in the "I hate Helicoils" piece I did last spring. Irontite makes aluminum tapered plugs as well. But you need some 'depth' to use them. And I don't think you have enough room to use pins... but that's why I was asking about pictures.

Best case is, as the OP says, machine the flange/sealing area. It raises the compression some, but on a UL (low compression engine) there is plenty of room to raise a bit of compression. There 'should' be a spec for how much can be milled off safely, which is what the OP is asking for. If the pits are deeper than that and extend far enough to prevent a gasket sealing... he has paperweights.

I'll be interested to see what they look like!

Cheers,

Sirhr

[Robert Luland]

Would it be to hard to fill the pitting with silver solder and then deck them? Just a thought. Bob L

[sirhrmechanic]

Can you post a picture?

There are some anaerobic filler products out there that can fill pits in a gasket area. Pyro Putty is one that comes to mind. But there are some better ones as well from, I think, Loctite. I can look up some names tomorrow at the shop. Not ideal vs. machining, but sometimes there is not enough left to machine or the part is irreplaceable. The high-temp epoxies can extend the life of a part that may otherwise have none left...

Cheers,

Sirhr

https://www.vintagegaragevt.com

[AZ pan]

I've already taken an 8" flat stone over the surface and can see how bad the pits are. The pits are even worse between the cylinder bore and valve area, what I need to know is how much I can take off. I know that with how low the stock compression is at and how much less its going to be if I leave it this way. I own a V-Twin machine shop so any maching that needs done is no problem. These pitts are not minor...
thanks for the reply Larry

[larry]

That surface can often be repaired by sanding on a flat plate. It doesn't need to be 100 percent to seal. A couple of strokes on sandpaper and you'll know how bad it is.

[AZ pan]

I have a set of cylinders that the top head gasket area is pitted and would like to mill this flat again but need to know how much can I safetly take off without causeing any problems. Also I am looking for a lifter block puller for this, understand that the UL's have to have a special puller. v-twin sells them but has been on back order for quite awhile now. Thank you for help help