Please don't laugh almost had a stroke when this happend.
I'll do the shortened version and protect the names of the innocent. Went to install my isspro gauges over the weekend. Tapped the wrong size hole in my exhaust manifold. Was able to plug it with a fitting and keep the truck rolling. So here is where I am. I have a 5/8 18 TPI hole in my manifold. I tried to get a sleeve or insert to get me to 1/4 NPT-18 needed to hold the probe. Having a hell of a time to get this off the shelf. I thinking this is a one off and could cost me some $$$$. Have a machnist freind that might be able to mill down and tap the fitting I'm using to plug the hole. Looking for another possible solution to my dilema. Thanks in advance

 

Plug that hole and redrill a new hole the correct size. It will look pretty crappy if you have to put 3 fittings together to make it work.

 

i thought isspro's were 1/8 npt pyros.

 

I have some 1/4 npt fittings for thermocouples but I am pretty sure there is no such thing as a 5/8npt tap.

They make a 1/4-18, a 3/8-18 and a 1/2-14, but the next size is a 3/4-14.

The drill size used for the holes are


1/4npt = 7/16
3/8npt = 9/16
1/2npt = 45/64
3/4npt = 29/32 (almost a 1" bit)

So what bit size did you drill? Maybe if we know the exact size we can get you a fitting?

Quad

 

Can you just drill and tap the plug that is in there now?

 

This is why im scared of doing my ISSPRO gauges.

That and metal shavings. lol

I've had my gauges laying around for a month now, I need to grow some ***** and just do it.

 

Hello
Just go with the next size pipe tap and bush it down!


Don Hammond

 

Go to :
www.mcmaster.com

They have every fitting ever made. Fast shipping also.

 

Actually was able to find a brass fitting to get me where I need to be. I should be able to finish up the install this weekend.

 

He used a 5/8-18 nf tap. thats straight not tapered.

 

hi,
If you tapped it with a 5/8-18 that would have to be a national fine straight thread and use a .578 drill. the best way to fix it right would be to go with a 3/8-18 nptf wich also uses the same drill and adapt it down to 1/4-18nptf. the 5/8-18 thread is so fine that the 3/8-18 tap will clean it up no problem. Im not sure what fitting you found to jam in there but since your thread is not tapered it wont work that good. good luck.....

 

Sell me your gauges!! I'll install 'em in my truck as soon as they arrive!

 

I'm surprised everyone missed the obvious. This is the best fix:

http://www.atsdiesel.com/ATSWebsite/...ExManifold.asp

It's fate... don't try to fight it.