alexboomin

Recently picked up a 93 FD RHD which is missing the vacuum port that goes to Brake Booster. The hole is 3/8" in diameter. I've seen online that it comes from factory with an insert that is just wedge fitted but I cannot find that part anywhere. Is tap and dye best alternative? See attached image showing hole.

R-R-Rx7

iTrader: (24)

I personally do not run the oem nipples for the vacuum ports . I have drilled and tapped them for AN fittings, even though the one you are mentioning i have left it untouched. Seeing the how much room there is around the existing hole it seems that you have enough room to drill and tap for a barb fitting.
i think a 1/4 npt to 3/8 barb should do the trick. You have to drill/ream to a 7/16.
given the angle of the hole i would make some kind of a drill/tap guide so you can drill/tap it straight

I am not sure whether you can press fit an oem stye barb fitting and still get a good seal around it

R-R-Rx7

iTrader: (24)

i hope this helps

alexboomin

Thanks lads for the advice. I will get a tap set and fittings on order. Will update with photos after installation.

MilesBFree

iTrader: (2)

i would suggest removing the UIM before drilling and tapping, to avoid getting shavings into the engine.

marksae

iTrader: (1)

What thread did you use to tap the two BOV lines?

R-R-Rx7

iTrader: (24)

i have both used 1/8 npt and 1/16npt. What you see in the pictures is the 1/16 npt.
For the 1/8 npt the wall thickness after tapping can be a little thin, i have done many of them but sometimes i got carried away and got the 1/8 npt a little too deep and the manifold cracked.
if you are going to do that i highly recommend a go-gauge for the npt fittings. 1/16npt to -3AN works well

also these are not for the BOV, these are for the fuel pressure regulator and one for the boost control

billyboy

Probably a 5 minute lathe turning job and probably cheaper than buying a quality tap and the fitting

mobash

iTrader: (4)

You’re in luck @alexboomin ! I just pulled the booster nipple from my UIM and can send that to you for shipping cost. Please PM me.

marksae

iTrader: (1)

Okay, thanks for the info. I am going to tap mine for 1/16 NPT. The wall does look a little thin on those two ports for 1/8 NPT. I am just tapping mine to install plugs in them for a cleaner look.

alexboomin

@mobash PM sent