VL Inlet Manifold Nipples

[Peter Cooke]

Am I correct in assuming that this cylinder wouldn't have left the H-D factory with the, I'm guessing, black sealant you can see at the back of the manifold nipple?
Seems unlikely as whatever it is has gone hard and flaky and would have a direct path into the combustion chamber which can't be good.
It doesn't look like the nipples have been replaced but the valve guides have so it could've been applied then.

I think the next step is to remove the black stuff and do a leak test and see where I'm at. Thoughts??

Manifold Nipple.jpg

[Steve Slocombe]

Dear Peter, it doesn't look like the inlet is seated, so may be an earlier replacement with an incorrect part. It has to come out.

[Peter Cooke]

Dear Peter, it doesn't look like the inlet is seated, so may be an earlier replacement with an incorrect part. It has to come out.

Thanks Steve, so you mean it's too short and should seat against the machined surface of the cylinder so there'd be no groove for sealant etc?

I thought they seated where the larger OD meets the cylinder when you screw it in but that was pure guesswork on my behalf, hence the question.

[T. Cotten]

Am I correct in assuming that this cylinder wouldn't have left the H-D factory with the, I'm guessing, black sealant you can see at the back of the manifold nipple?

There was no evidence of any sealers in any of the H-D nipples that crossed my benches, Peter... (Only NOS Chiefs, and it was white.)

...It doesn't look like the nipples have been replaced...

Your photo doesn't show the rivet, which always tells the story.

I think the next step is to remove the black stuff and do a leak test and see where I'm at. Thoughts??

If it does not produce bubbles under a constant 1 atm, and the manifold and nuts were assemble-able, don't fix it.

Good luck!

....Cotten

[otis71]

Often the rivet leaks. Years of wrenching oblongs the rivet hole. Ream it round and make an oversized rivet to fit. Sealing the threads doesn’t work well because they’re not tapered threads. A little JB Weld on the inner surface where the nipple seats helps and handles the heat.

[Peter Cooke]

Thanks for all the tips gents. I've confirmed that the nipple length, ~ 760 thou, is the same length as the repops available from Replicant Metals so I'm assuming the nipples are correct??
Manifold nuts screw on just fine so no issue there. So the next step will be to clean the crud out, run the bubble test, and see what I get.
Pic of rivet attached.

20250915_143908.jpg