Priming cups do not face up

[Michael J. Barnes]

On the block of my 1924 Cadillac there is a priming cup for each cylinder. Three or four of them have the cup upright when they tighten, but others go around nearly another half turn before they tighten. Seems to me it looks better when the cups always face up. Is Loctite a solution to this? Put it on the threads, turn till the cups are up, and tighten no more? Will the Loctite do the rest of the work? I would like to hear what product is recommended for this. Thanks.

Edited October 27, 2021 by Michael J. Barnes (see edit history)

[Mark Shaw]

I suggest gas tank sealant would prevent leaks if not completely tightened.

[prewarnut]

Another solution is a small thin washer filed to size so not seen when seated. Why the condition exists in the first place is a question unless this happens...Or, the base of the priming cup could be machined (if it can be chucked on a lathe's independant jaw face).

[ejboyd5]

I would pursue the washer idea, much like indexing spark plugs.

[Mark Gregush]

Priming cups generally have pipe thread, so don't think washer will help. You might try recutting the thread in either the head or on the priming cup just a little more with the proper size NPT cutter. Or you could wrap Teflon tape around them. People used it on spark plugs all the time.

[Michael J. Barnes]

Thanks, all, for suggestions.

 

[LI_BENTLEY]

Swap them between cylinders until you get top facing with a good tighten up.

[26-25Buick]

The priming cups also need to minimise leakage during the compression stroke. Would the Loctite be able to do this task?