Hey, Im trying to install my Pyro guage and the directions from TST make NO sense to me!!! Im wondering if I have the wrong thermo couple or something. The TST direction says to drill a 5/16 hole then tap with a 1/8-27 NPT tap. The thermo couple I have has a 1/4 thread. Im kinda confused and need to get the guages installed by tomarrow!!! (Going up to the mountains and need to watch the EGTs!!!)

If you could help me, Id really appreciate it!!!

Thanks,

Sam

 

The directions are right for the TST pyro. It's 1/8" pipe thread with 27 threads per inch. For some reason, pipe's measured ID, not OD. It confused me too until i took my pyro threads in to sears hardware and looked at the 1/8-27 tap. It's a perfect fit for the TST pyro. My store had just one of them.

Which pyro do you have? TST? ISSPRO may have instructions on their site. Otherwise, contact your reseller for the correct information. :-

brandon.

 

It's OK, take a deep breath...

Then go ahead and drill in the same place (in the manifold as per TST) for a 1/4"NPT tap. I think it's 7/16"dia., but read the tap or a tap sizes chart.

I have a VDO pyro, and it uses a 1/4"NPT adapter. The larger threaded fitting is generally considered a little more durable. Use a little anti-seeze on the threads.

 

For a 1/4 inch probe, you need to drill with a 7/16ths bit, and tap with a 1/4 x 18 NPT tap. I had to hunt down a 1/2inch drill because the bit i had wouldn't fit in a 3/8ths drill. I installed an isspro egt, and that's what I used.

 

Ok, I looked at the manifold and if I drill for the 1/4 thread, it looks like the pyro probe will be scratchn the bottom of the manifold.

The TSt directions state that the probe should only stick out .300 to .700 in, but it seems like the one I have would protrude more than that... maybe Im wrong, I'll go measure it.

 

Your probe may be longer than TST's, mine was a little I think.
Just tap the hole deep enough so that the end of the threaded bushing is about flush with the inside of the manifold.
About 4~5 threads.

If need be, move the location slightly towards the head. That should put you in a little "deeper" spot.

 

Ok guys, thanks for the help!!! Im gonna go get dirty now, so wish me luck!!! Hope I dont screw anything up!!! :'(

 

Good luck.

Look on the probe top for a ferrule. If there, you can set the depth of the thermocouple in the exhaust manifold by moving (sometimes tapping with a hammer on the nut above the ferrule to move the ferrule down the thermocouple.

 

GB,

I always like to drill them for the 1/4", and then use a brass reducer to go from 1/4" to 1/8". The probes are usually made of stainless steel, and the manifold or elbow is made from cast. The two are almost impossible to seperate after bring heated so many times. The brass reducer make future replacement much easier. Also don't forget to use anti-siez on the treads, and aliitl on the probe, where it locks in.

 

Thanks for the help guys!!! I havent had a chance to install them yet cause I was way too tired last nite and it getting too late tonite. I wanted to have them in by this morning cause I was going up to the mountains and need to watch the EGTs, but I was careful with the ol right foot.

I'll let ya guys know once it in...

Thanks,

Sam

 

Grey,
You might think about removing the turbo from the exhaust manifold before you drill. Ive read people going bth routes, but for my piece of mind, I disconnected the turbo and taped the inlet so no shavings would fall in. Put a vaccum up to the exhaust while drilling. Just to be sure. Either way, take your time and good luck.

 

Thanks. I cant seem to get the bolt loose where the turbo attaches to the manifold, because of the awkward position. Is there a trick to it or do I just need to soak it with some rust remover and work it loose???

Thanks,

Sam

 

It is not necessary to remove the turbo.

Use grease on bit & tap, wiping it off often- catches most shavings. You can also place the nozzle of a shop vac right next to the spot like I did, then use a slender magnetic retreiver to fish any remaining chips out. Anything that gets past all that will just blow right through the turbo when you fire up the engine.

Otherwise, just use the best penetrant you can find and be patient. Be ready to drill through the bolt and re-tap if it breaks off.

 

I think I will take your advice VinDiesel, Im gonna leave the turbo on. I'll just do a good job at greasing the bit and using the ol magnet!!! Then, should I let it idle a bit???

Thanks,

Sam

 

U can do that if you want but to me you don't want little chunks of metal in you turbo.