SPA EGT Tap size???

[sonofagun]

Not sure which forum this belongs in is it engine rrelated or an accessory? I am sure our superior group of Mods will put me in my proper place!!

I am Installing my SPA boost and EGT guage today and need to confirm the tap size for the exhaust manifold ------------??

Thanks in advance,
Bob

[hoot]

That depends on the size fitting that came with your thermocouple. SPA has changed them over time. Some are 1/8 NPT and some 1/4 NPT

1/8-27 NPT is "R" drill (.339")
1/4-18 NPT is 7/16" drill
3/8-18 NPT is 37/64

[chuntag95]

You can also use an 11/32 (.344") for the 1/8 NPT if you cannot find an R. I used one without issue.

[sonofagun]

Thanks guys,

Hoot,

Guage is in. I,m running regular juice with JK 4" exhaust. What is the max EGT that I should expect to see? I tow a 12000# 5th wheel at times.

Thanks,
Bob