Your ported vacuum switch will be pipe thread... something I don't believe helicoil supplies.... They should be able to remove the remnants of the PVS without damaging the threads.
FWIW, shit happens... if we send something to a machine shop, we should strip anything we want to "save" from the casting....
Vucuum? A few inched below atmospheric, almost any thread sealant should work. I like Permatex Aviation. Hi temp pipe dope will work, too.
wws
Does anyone know if Helicoils are water-tight? I just got my head back from the machine shop and found that in removing a ported vacuum switch they broke it flush with the little block. It wasn't their fault because I couldn't remove it and they had to remove it to do the machine work. I want to bring it back and ask them to drill out what's left of the ported vacuum switch and install a Helicoil.
Thanks in advance
Drill it out to close to the right size, pick out what is left, and clean up the thread with a pipe tap.
Note: Use heavy grease on the tap to capture the shavings.
Good idea, but not critical with the head off the car.
What makes you believe a bolt bolted into a helicoil, would not be just as "water" proof as and any other bolt bolted into a hole? ;)
NPT, by its very design, is leak proof when properly tightened
OK... let's go back over this... "without damaging the threads".... Damaged threads... what a concept.... If the threads are damaged on an NPT connection, you can bet that there is a very real chance for a leak.... Running a tap in and giving an extra half turn, is often all that is required to deliver new, undamaged threads. This allows an appropriate sealer for the metals being joined (and yes, there are times when "no sealer" is the appropriate sealer) to ensure a leakproof joint....
All the same, do I sound like I need instruction on pipe threads?
No but my post was direct to the thread. You correctly stated it is a NPT, I simply point out for others, reading what has been posted, that NPT threads seal by design. Pipe sealers are in reality lubricants that allow the connection to go far enough the "incline" of the pitched thread to make the seal. ;)
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