What do you think about my nipples?

[Neil74]

I agree with cotten on this one clean the face up where it contacts seal. Take your intake nuts and seals and try them on the bench, don't over tighten, if they screw on easy and appear to snug up they should work. Remember to leave your base nuts loose when installing on engine, so it all lines up right. Only when absolutely necessary should you replace those inserts, there has been more damage done replacing them than leaving them alone. Definetly a case of "If it ain't broke don't fix it!" Good luck Neil74

[Knotthed]

Neil74,

Only when absolutely necessary should you replace those inserts, there has been more damage done replacing them than leaving them alone. Definetly a case of "If it ain't broke don't fix it!" Good luck Neil74

Do you speak from experience here?

I'd like to hear some stories on this. I have heard that this is part of the standard process to rework the aftermarket cylinders available? I'm sure new ones would be easier to rework than old used rusted cylinders.

Any bad stories appreciated.....
Any fool proof instructions also appreciated.....

[Chris Haynes]

I think Neil may be referring to damage done to aluminum heads when removing the nipples. Cast iron isn't much of a problem.

[T. Cotten]

I think Neil may be referring to damage done to aluminum heads when removing the nipples. Cast iron isn't much of a problem.

Aluminum castings are most delicate of course.
But plenty of cast iron castings have been compromised by botched nipple replacement as well!
The riveting process, often compounded by movement of the nipple upon the rivet from severe over-torquing, "upsets" the internal threads to produce burrs that can cut their own threads on the way out, if un-screwed callously.
That is why crushing the nipple is the preferred means of removal.

Occasionally the nipple can be punched slightly inward, through the rivet hole after the rivet is removed, giving enough clearance to un-screw without damage. But any resistance at all indicates a problem.

And a slightly over-sized rivet must be installed to a reamed press-fit hole, to minimize the peening process as well as retain authentic appearance.
Beware of huge soft rivets often supplied with modern nipples. They are as poor an idea as the silly o-ring usually included with the kit.

Beware of other fuel-damageable band-aids as well, such as saccharin-based thread-lockers. It is quite dis-heartening to have to pull a second nipple, and cut and ream for an over-over-sized rivet, only because your goober failed.

Please also note that any goober is only a hedge on your bet, as the sealing interfaces are where the nipple butts up against the casting, and around the rivet, NOT the threads themselves. Often the casting counterbore must be dressed. (Knucks have a thin lip that is quite delicate. I haven't had enough Flatties out to determine if any have this excellent sealing aid.)

Modern nipples must occasionally be cut to length; Beware of productions where the inside champher is too large for the mating nipple.
Parkerizing must be removed for some sealers to adhere properly.

Make certain the new nipple is completely cured and sound unto itself, before attempting the riveting step.
Never re-use a nipple with a previous rivet hole, and never expect one to line up with the casting hole. 'Tis folly.

Please review http://virtualindian.org/11techleaktest.html for other notes on the riveting step,

....Cotten
By the way: Liberty curtailed offering motor service, so please don't anyone ask.

[Neil74]

Thanks guys, yes speaking from repairing many attempts by others on replacing these nipples. There was a period where everyone had to have the o-ring seals,they seal so much better Between beating them out with cold chisels, resealing with everything imaginable and then attempting to peen the rivets supplied with anything that would fit the hole half way. More often than not they leaked worse than before they were screwed withNow with modern fuels, most sealers won't stand the test of time, so if it ain,t broke don,t fix it!

[cdf6333]

Stupid question, but do these come out like the 1940 and up? I have stripped them and changed them on the bike years ago. Once I even made O-ring inserts for a custom Chief.
The late Chiefs just have a rivet which when drilled out, lets em unscrew. I might even have some NOS around here somewhere. Good luck!

[Knotthed]

OK.

Expecting a knock down drag out battle with my nipples, they came out relatively easy.

I ground down the rivet even with the cylinder with my dremel tool and then carefully punched them out with a pin punch.

I have read Cotten's manifold leak test procedure.

Any other tips for installation?

If not, then I will be trying to figure out the best way to fab my peening tool. Any suggestions here? Anything stock to make it out of? Does it need to be heat treated?

Thanks again,