I am trying to get together all materials and tools required so that I can install my pyrometer and boost gauge right away when my truck gets in. I have found what I believe is the right tap for my pyro probe, a 1/4-18 NPT. My problem I can't seem to locate a tap handle big enough to handle this tap after checking a few local hardware stores. Haven't checked Sears yet. Could someone who has done this install provide info on what size tap handle I need. Would sure appreciate it.

 

Got a cresent wrench and a steady hand ? The cast iron taps VERY easily. I work at a machine shop - have access to every tap handle known to man - and have put 3 pyro gauges in using a cresent wrench for the tap driver....you shouldn't have any trouble.

 

Hmmm, I believe I could do it that way. As I have never done any tapping (do, of course I intend to practice before operating on my new baby), I just want to make sure I don't mess up. Using the cresent would save some money as I would not have to buy a big tap wrench that won't see much use after installing the pyro probe. <br>Thanks for that reply, MisterKTM. I'll try my crescent wrench.

 

Just make sure you get the tap started in straight up and down. Once it gets started they will pull themselves straight but it needs to be as close to perpendicular as possible to start with.<br><br>Also, make sure you use the template that comes with the probe and do not drill dead center the housing (if pre-turbo). There is a ridge inside the manifold in the center that you don't want to get into. If I remember correctly the offset is 5/8&quot; left or right of centerline of manifold.<br><br>One more trick - let the truck idle while you are drilling/tapping - it will blow the chips out at you and you don't have to fish them out or worry about missing any. The drill tip will get hotter due to the exhaust heating the manifold but a little cutting fluid will help.

 

You can use a socket and a ratchet. That's how I did mine and it's worked fine now for over a year.

 

Socket and ratchet? That sounds like another good approach I could use. Also thought about using a drill on real low speed, but I think I stay with one of the by-hand rotation methods above.<br>I have read previously about not dropping the turbo and just to leave the truck idling to blow out the metal pieces during drilling and tapping. It sounds like it would simplify the installation quite a bit (long as you don't burn your fingers), but I am admittingly having a difficult time trying to picture how some of the metal chips might not be drawn down into the turbo along with those blown out the drill hole while the truck runs.

 

[quote author=MUDDY link=board=7;threadid=13481;start=0#126944 date=1050075555]<br>if u got exhaust brake turn it on. also use vaseline on bit. the backpresure will blow the shavings out the hole u r drilling<br>[/quote]<br><br>I can see with back pressure and with the engine running that there is pressure in the exhaust manifold flange from above and the back pressure causing pressure from below. OK, I can see now how the metal pieces are shot out the hole. Without an exhaust brake, can you partially or completely block the end of the tailpipe to create the same back pressure as an exhaust brake?

 

I'd only partially block it.

 

Ratchet & socket...got it. That's what I was wondering. There was no way I was going to be able to fit my T-handle in there!

 

I've done dozens of them this way, never a problem.

I used to be very careful of chips going down into the turbo after seeing two turbo impellers warped from overheating when a chip stopped the turbo from spinning. Started removing the turbo before tapping, but after thinking on it a bit decided it was a waste of time, as are greased taps and fishing chips out with a magnet.

The way I do it now is after drilling and tapping start the engine with the turbo intake hose removed. If the turbo doesn't start spinning immediately shut it down, turn the turbo fan backwards to free the chip then start it again.
All the chips will blow out the exhaust.

 

I'm aggravated about the wiring that I got from Autometer. On the probe, the wires are staggered, so the connecting bare nuts don't touch each other. On the lead coming from the gauge, they are even, so the long wire is going to have a big loop/bump in it. Yeah good luck fitting this into the heatshrink tubing.

 

I think they do that to compensate for slightly different readings from the probe.
No two probes are identical, so they stagger the wires to make the readings the same at the ends of the wires.


phox

 

i matched the tap to fit in a socket and used a ratchet

 

TinJim,

Double check the size of your thermocouple too, all the ones we sell are 1/8th NPT, Auto Meter, DiPriocl and Isspro etc. Better safe than sorry!

Mark @ DPPI

 

Haha yeah that would suck pretty bad. I ended up buying a 1/4" NPT tap & 1/4" MPT-1/8" FPT adapter in case the autometer probe was too long, so I could space it out some. Didn't end up needing it though.