2nd Gen Non-Engine/Transmission EGT probe drill bit size

[JWaters]

What size drill bit do i need to drill the hole for a autometer 3344 egt? And what size tap? It is a sport comp gauge. I am drilling tha exhaust manifold

 

[DRuth]

Double check, but my Autometer EGT guage uses 1/8" NPT threads. I bought a 1/8" NPT tap at Homer D. for a few dollars. It came with the right size drill bit.



Have fun



Dave

 

[JWaters]

I have a tap I need to know drill bit size



thanks

 

[lmills]

mine said size Q. I think that is somewhere around 21/64's

 

[lmills]

I just checked my paperwork from Geno's.





1/4" npt is 7/16's bit

1/8" npt is 5/16's bit

 

[JWaters]

thanks 5/16th's

 

[y-knot]

If you are about to install your probe, I have always had better luck going with the 1/4" NPT size and then using a brass fitting to reduce to the 1/8" NPT size of the probe. The manifold is cast and the probe is steel, after they have been run and gotten heated they do not want to separate, even if anti-seize is applied. So the brass fitting separates the two, and makes re-placement it it is ever needed, much easier. Also for the 1/4" tap you will need to drill a 7/16" hole. Good luck

 

[crabman]

Tap/Drill chart

Go Here:

http://www.engineersedge.com/tap_drill_chart.htm



crabman

Hey, the link worked!!