Back on my 23 TT the old ex pipe nut had broke and been brazed years ago. It will go on the manifold...wont tighten up. Bought a new Nut,doesent want to start,threads on manifold are in rough shape. I can use a thread file and clean them up some. Should I heat the new nut up and try starting it then?
Suggestions? I can get my hands on probley 4 other ex manifolds but they might be in bad shape also.
Thanks
Try wrapping the threads on the manifold with aluminum foil and reuse the old nut.
If all else fails you can buy a new manifold. They're "only" $85.
Yes the threads can be cleaned up with a thread file (or even a hack saw blade). Also consider working the new nut on and off, back and forth, with a little valve lapping compound on the manifold threads. Some of the new nuts start out a bit tight. When I replaced the one on my boat-tail, it took about fifteen to twenty minutes with the lapping compound.
Some manifolds just are not savable without too much welding and machine work.
Good luck!
Drive carefully, and enjoy, W2
Let me toss in a helpful hint that was given to me by somebody here. I bought a new exhaust pipe and nut for my car. Had to cut the old nut in half to finally get it off the manifold. Got the new nut on and tight using the valve lapping trick, thanks again to those here. Every time I would come home from a ride the pipe would be loose again?? I'd tighten it up (cold) and next ride the pipe would be wiggling again? Tighten the manifold nut up tight (cold) but after a ride snug it up again while the manifold and nut are hot, no more problems. Sure would be nice if the aftermarket exhaust pipes had all the bends in just the right places though.
You can put several nuts together, and if they are reproductions, they can all be different. If one doesn't work, try another, until you find one that works properly. I always try to find originals. They work.