So I drilled too big for my Apexi EGT probe. Stupid instructions said drill a 8.4mm hole...uh too big to thread 1/8 NPT. So I was thinking of either.

1) Weld on a 1/8 NPT Steel Nut on the hole

2) Get some sort of reducer so I'll drill the hole to like 1/4 NPT and thread in a reducer to 1/8 NPT, but I need it to be weldable...like steel not brass.

Any other options.. thanks
Alvin

http://www.cardomain.com/id/96rst

https://www.innovativetuning.com/osCommerce/product_info.php?products_id=1433

...can you weld brass to cast iron???
Alvin

http://www.cardomain.com/id/96rst

You can weld just about anything together, but you don't want to use brass right there. Stick with option 1 - Weld a 1/8 NPT Steel Nut on the hole. If you can't find a steel nut then cut out a thick enough peice of steel stock, tap it and weld it over the hole.


95 Eclipse RS : 5 speed
15.7 @ 87.9mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

I think you are confusing 1/8 NPT with 1/8 !!!!!!!!!!!!!

when I do 1/8 NPT I have to drill 11/32 which is 0.34375 inch
most tap chart will tell you to use 11/32 for 1/8 NPT
drilling 8.4 mm is 0.3307, even smaller than 11/32 leaving even more metal to chew with the tap

Alain

when I did mine I welded about a 1/4" piece of stock to my manifold and drill and tapped thru that just so I would have more threads to work with. I can't see why you couldn't do the same. :thumbsup