Pyro Probe Installation

[jgallentine]

Well I finally got a 4" exhaust system and a full compliment of Autometer gauges. The guages I am installing include a fuel pressure, boost, single channel EGT and a dual channel EGT.



My question revolves around the installation of the probes for the EGT gauges. I will be installing one probe for the single channel gauge in the exhaust elbow after the turbo. This task seems relatively straight forward. The two probes for the dual channel EGT gauge will go in the exhaust manifold, one on each side of the center web. Finally, HERE is my question:



Have any of you that have drilled and tapped your manifolds for the EGT probe ran into any difficulties? Can I just go to the hardware store and get the appropriate drill bit and NPT tap? I have drilled and tapped regular steel and aluminum but never cast iron. Are there any pitfalls in drilling and/or tapping the cast iron manifold that I should be aware of?



Thanks for the input... it looks like it's going to be a busy weekend.

 

[plongson]

There is nothing too difficult about tapping cast and you can either take the manifold off or leave it on. It is personal preference. Just get all the chips out with a magnet etc if you opt to leave it on.

The BEST way to tap a pipe thread, is to follow up the tap drill with a tapered pipe reamer. This eliminates all the stress encountered trying to take a straight hole and make it a tapered hole. The down side is that unless you have machinist friend, they are hard to come across. The good thing is that the manifolds are thin (and cast is very soft) and quite easy to tap. just be careful not to go too large with your tap drill. Don't ding it too hard with a center punch either, a center drill is a better choice for starting your hole.

Good luck and go for it!!

 

[MCummings]

Originally posted by jgallentine

The two probes for the dual channel EGT gauge will go in the exhaust manifold... . one on each side of the center web. ]

Any reason to do this? I'm curious what your reasoning behind this is.



Thanks,

Merrick Cummings Jr

 

[jgallentine]

Plongson - Thanks for the information. I have thought about taking the manifold off and having a machinist tap it but that seems extreme. One question though, what is a center drill? I have a spring loaded automatic center punch for aluminum, not sure it will work on cast iron though.



MCummings - It is my understanding that the exhaust manifold has a center web in it separating the front three cylinders from the back three. I wanted to have a probe on each side of the web in case of individual cylinder trouble from something like an injector failure. This is probably over-kill but I work in the parts distribution business and get a pretty good deal on the parts. The 2 channel gauge also gives me an audible alarm that I can set the temperature trigger on. I also opted for the quick shift light which gives me a visual alarm as well.

 

[drrhoades]

When drilling and tapping the hole in the manifold does it matter if the manifold is hot or cold. The reason I am asking is that I will probably have to drive at least 20 minutes to do this. I am assuming that it shouldnt be hot. I was thinking that if it was a little warm the it wouldnt matter but if anyone knows the right answer that would help alot.



Thanks



Doug

 

[Extreme1]

Instead of a tappered ream use a countersink, way more available. I do it on all tapped holes and it's much easier to start the tap than no countersink.



The auto centerpunch will work fine.



You can tap the manifold as hot as you want, just don't burn yourself.



Make sure the tips of your probes are in the center of the passage when you tighten them down!

 

[dieselshu]

EGT sensor install

Check out this link http://www.dieselpage.com/gimain.htm.

It has the instruction to install the pyro probe. easy and straight forward.





Dave

 

[illflem]

Since Dave's link above doesn't seem to work try this one-

http://www.tstproducts.com/gauge_install.html

 

[jgallentine]

Thanks for the links. Even though Dave's link didn't work I was still able to go to the home page and find the information. Both sources have great information. My goal is to get all three probes and the exhaust installed this weekend. Hopefully next weekend I will be able to get all of the gauges mounted and wired.



I will post updates of the project as it goes.



Thanks again for all of the information!

 

[plongson]

QUOTE]Originally posted by jgallentine

Plongson - One question though, what is a center drill?





Also, countersinks DO work great for chamfering a hole to get a tap started but the tapered reamer actually gets a hole ready to accept a pipe tap, all the way to the bottom. If my memory serves me, the taper on NPT is 1/2" per foot. Most of the time you get by without them, but on full length tapped holes or tough material (stainless etc. ) it make all the differance in the world.



Here is a picture of a center drill.

 

[jgallentine]

Gaskets

Are there any gaskets between either the exhaust manifold and the turbo or between the turbo and the exhaust elbow?

 

[wsmalley]

I'll save you the trouble... . LEAVE THE TURBO ON.



Any pieces not picked up by a magnet will simply blow right out of the exhaust side of the turbo. It is simply not worth the effort of taking everything off for something you can do with a small magnet, or really just crank it and blow it, nothing will catch. From talking to Jeff Garmon and my mechanic here in Macon, niether have had ANY problems just drilling tapping, wiping off the top, installing NPT and probe, cranking, and going.

Just my opinion though, but to answer your question yes there is a gasket between the manny and the turbo. Not sure about the elbow though I wouldn't think so.



Will

 

[illflem]

After seeing one turbo impeller warped and hearing of another due to a chip wedging in the tight clearances of the turbo and stopping it I will never again drill and tap without removing the turbo especially if it's someone else's rig. . Removing the turbo is no big deal, probably just as fast as fooling around with magnets. I've always used the gasket over.

 

[Blakers]

How hard is it to remove a turbo on a new truck? I thought it might not be a bad option. Is there just four bolts? One would not have to remove the exhaust just to move the turbo enough to get a piece of cardboard in between, would they?



This site suggests removing turbo http://www.dieselpage.com/gipda.htm



Thanks,



Blake

 

[Loren]

When I did mine, it was late and I was tired. Big mistake!



I thought I had the proper drill, but it turned out to be too big. The fitting would screw into the tapped hole, but never got tight. I thought I would have to buy a new manifold. I finally got smart and went to bed.



The next day, after thinking it through, I removed the manifold and brazed the fitting into the hole. Removing the manifold was surprisingly easy, and it allowed me to clean the drill chips out at the same time.



Brazing the fitting is obvously permanent, but if I ever want to remove the fitting badly enough, I can buy that manifold that I thought I'd have to buy earlier. I don't see that happening.



I don't recommend this procedure, but if you screw up the hole, this is a solution.



Loren

 

[Joe G.]

Don't forget the oil drain pipe on the bottom of the turbo. Take the two screws out of it first.

 

[jgallentine]

Oil drain pipe

Thanks Joe, I would have missed that one until I was wrenching on the turbo wondering why it would not come out.

 

[illflem]

Loren, you can also tap the hole to the next pipe size up and use a reducer.



I always remove the oil return line by just loosening the screw clamp on the lower end on the block. Much easier to get at.

 

[jgallentine]

Exhaust and EGT probes are in!

Well I finally got some work done and the 4" Hog Performance exhaust is on as well as the three probes for my EGT gauges. Unfortunately, I didn't get to the inside of the truck to start installing the gauges. As you may have read on antoher thread, my AC evaporator core is leaking and my whole dash has to come out. I am just going to put the gauges in when I fix the core if I do it myself. Otherwise, I will wait until it is done at a shop so there is not extra wires in there for them to deal with.



The exhaust is pretty nice, the downpipe fit nice and I had good clearance around the spare tire. The hangers do not hold it very securely so I had to add an extra hanger to keep it from bouncing up and having the exhaust tip hit the fender when I go over bumps. The sound is good, but I think I am going to miss the obnoxiousness of the straight pipe. I may have to get a muffler eliminator for this system too.



Thanks to all those that offered advice on the EGT probe installation. It really is a straight-up deal. I just used a normal bit and drilled and tapped all three holes without incident. I did take the turbo off since I wanted one in the elbow too. It realy doesn't take very long and was worth the piece of mind as far as metal shavings are concerned.