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Hi All,
I am trying to figure out what size and type of fittings these are on the sheet metal intake I had made 10+ years ago (The 0.35" hole has 28 TPI and the 0.57" hole has 18 TPI, I cannot tell if they are tapered....). NPT or....? Help?
When in doubt, tig in filler metal, then redrill and retap to your liking. No more guesswork.
edit-- Since those are just vacuum ports, you could even epoxy them closed and redrill later if need be. Unless you are running tractor pull diesel levels of boost, you could even solder fill them. Hell, for that matter, melting in a thermoplastic such as ABS, nylon, or polycarbonate would also do.
When in doubt, tig in filler metal, then redrill and retap to your liking. No more guesswork.
edit-- Since those are just vacuum ports, you could even epoxy them closed and redrill later if need be. Unless you are running tractor pull diesel levels of boost, you could even solder fill them. Hell, for that matter, melting in a thermoplastic such as ABS, nylon, or polycarbonate would also do.
I am having a machinist stop by next week to take a look, if they cannot figure it out epoxy it is! (I can Tig weld, but its not pretty...) and not running any boots only N2O
I would guess manifold vacuum and vacuum for the brake booster(the larger one)..
They do kinda look like they are for AN style fittings(Like RB04AV noted above) , but hard to tell in a picture.
AN fittings have a o-ring on the straight thread side that would seal against the flat surface around the holes.
You can also buy hose barbs with a AN thread on them.
AN fittings have a o-ring on the straight thread side that would seal against the flat surface around the holes.
True dat. There are also some that use a sealing washer, nylon or something. For that matter, you can take an O-ring one, and make a flat gasket for it: lay some thin hard gasket material against it, tap it with a hammer to get the outline, cut with a razor blade. Or maybe even, since it's just vacuum and not fluids of some sort, dope it up real good with thread sealer and screw the adapter fitting in there without an O-ring or gasket at all.
The smaller one, not sure what's going on there. 28 tpi is the size for ¼" fine thread screws. That'd be a REAL SMALL fitting. But the ID of it is a bit over 3/16", meaning the screw size would have to be bigger than that. Not sure what it could be. Maybe you could drill & tap it for an adapter like the other, for 4-AN maybe.
Personally I'd avoid welding on it any more, or epoxy, or any of that, if at all possible. If I could get, or make, a fitting that fits, that seems it would be better.
Thank you all for the support! The smaller hole actually is not 28 TPI but rather 27 TPI and a 1/8" NPT tap fits great, I am now guessing the larger hold is 1/4" NPT. I have ordered a bunch of fittings from Earl's and I'll see what works best. The intake is by Becks, I am not sure if he is still making them and this intake has been in my shop for at least 10-years on the shelf. The larger hole is for the brake booster, smaller hole is an extra, and the center non-threaded hole with the channel piece is for the MAP sensor. It makes sense that the extra hole would be for a remote MAP if this was boosted.
I appreciate everyone's help and support! Have a great Thanksgiving and I'm glad this board is still running. Take care all
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What is this fitting on my intake?! 
