What size tap to use on GT40 intake?
- Thread starter 66 Tiger
- Start date
and need to tap a hole for the egr coolant line and the other sensor at the front of the intake. Does any one know what size tap I need? Thanks....
65ShelbyClone
Founding Member
Sounds like you have an Explorer lower because if you got a GT40 from Ford Racing it would have those holes tapped. Was this an Ebay find?
I'm thinking the holes are around 1/2 or 5/8" NPT, but you can tap it for any thread as long as the coolant line will still fit on the barb and you have enough metal around the hole.
I'm thinking the holes are around 1/2 or 5/8" NPT, but you can tap it for any thread as long as the coolant line will still fit on the barb and you have enough metal around the hole.
Michael Yount
Mustang Master
You can fabricate this to make it work. See what size coolant hose you need to fit the fittings on the egr spacer. Then go to Home Depot and find a brass fitting that is barbed on one end (the barb size has to be one that will take the same size coolant hose) and threaded on the other end. Get the one with the smallest threaded male end on it. That's the size tap you will need (to match the threaded end of the barbed fitting). The tap package will tell you what size hole you need to drill. Alternatively, the Cobras didn't come with any coolant lines to the egr spacer. You could simply block off the nipple from the metal tube, and cap off the nipples on the spacer and do without it completely.
Michael Yount said:
Thats a great idea! I didn't even consider going to H Depot to pick up the fitting. That way I can get away with alot smaller tap diameter that that OEM fitting. Will teflon tape be ok to seal the threads? Thanks....
Also, do you think there are any advantages / disadvantages to blocking off the lines..... I'm thinking that if SVT did it to the Cobra's it must be a good thing?
Michael Yount
Mustang Master
Teflon tape is ok - it lubes them more than seals them, for a tight tapered-thread seal. There have been mega posts regarding whether the coolant lines are there to cool the components from the exhaust gas flow, or to provide a bit of 'heat' during certain cold-start conditions when the combination of low temps, and flow across the throttle blade can 'squeeze' moisture out of the air causing icing in the throttle body. I simply don't know which story I believe. I do know that many, many people have simply deleted the lines with the egr in place with what seems to be no noticeably bad side effects. Your choice. If you've got visual emissions inspection, I'd probably hook it up just so it looks right.
I used the coolant tube that came with the explorer manifold. The ECT fit right in, just barely clearing the distributor. I ended up up extending the ECT wiring to make a nice fit. All the coolant lines for the EGR were in the right place. I used a couple of pieces of 1/2" copper tubing and some elbows to bypass my failed heater. Sweat soldered them together to make a "U" and stuck it in the heater hoses as they came off the coolant tube.
Ok, so now I am done. I decided to just bypass the EGR coolant lines & I am going to locate the air sensor to the air box, Everything seemed to go together well & the mods relly woke the car up! My only problem has been with the idle, It now surges from 400 to 600 rpm a couple of times and then shuts off. Anyone have any ideas ?
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