Drilling for pyrometer, a litle nervous

[DFrank]

I want to get a pyrometer, but I am nervous about drilling a hole for the probe. I went to a fancy 4x4 shop, and he quoted me over $400 for parts and install. I plan to buy Auto meter's $ 100 dollar version and do it myself, but how hard is the install? Do you have to remove the pipe, or can you safely drill, by sucking the chips up with a shop vac, as you drill.



I also couldn't tell from the website i looked at (Summit) if everything I needed besides the pod would be included or if it was just the gauge itself.



What is better about the more expensive ones? I don't plan any serious mods, I just want to be safe pulling medium loads through the Rockies as fast as possible.



Thanks, Dave

 

[SBashaw]

Ya, it gets your heart pounding alittle faster when you drill and tap for the pryo! I just plugged off the tail pipe with some duct tape, started the motor and drilled away, the chips came flying out the hole as i drilled (wear eye protection) had no problems.

Just go slow. Good luck!

Steve

 

[Forrest Nearing]

also realize that you would really have to TRY to cause a problem... just keep a shop vac up next to it as you drill, maybe fish an extending magnet around in there, hold the vac over the hole, etc. but I doubt you need to pay that much attention... a few flakes of iron are going to blow right past the turbine if they do end up in there. grease the tap up and take your time with the tapping, and you'll be fine.



Forrest

 

[GFoley]

Iwas also concerned about drilling the exhaust manifold. I used tap oil when I drilled and grease to catch the chips when I tapped. One member suggested to start with the 1/8" tap for the first try. If you mess up you can always try with a 1/4" tap the second time but you cannot do it the other way. Just go slow, drilling cast iron is not easy anyhow.

 

[CIverson]

I was really nervous when I did mine. I drilled mine just above the turbo. I undid the turbo from the manifold and undid the oil drain hose. Stuffed a rag in the drain hose hole on the engine, and covered the exhaust inlet of the turbo and then drilled, and tapped.



Tapping is kinda a PITA. No real good suggestions except make sure you get the right NPT tap and go slow.

 

[Butch Brandt]

Just like SBashaw says! With tape over the tail pipe and the engine running there is no way chips can get inside.



Start with a cold engine and EVERYTHING ready. You will find the cast iron soft and drills easy. Shop practice says drill cast iron dry--no oil or fluids. If you are used to working in gloves you will probably want them for tapping. The exhaust gas coming out by the tap will be pretty warm on the hands.



You will need to wear eye protection. If I do it again I will be wearing a face shield just to keep the hot chips off my face.



Good Luck!

 

[SMorneau]

Taps are much easier to use if you have a T shaped tap handle. It's possible with a wrench or vise grips but not as easy and you are much more likely to break the tap which of course is just about the worst thing that can happen. Work the tap back and forth it should never require much torque to cut threads with a sharp tap in the Cast. Drilling is easy also if you have a sharp bit.

 

[Ol'TrailDog]

Since I had the wheels and fender liner off for installing the jake ebrake I drilled the manifold in the front collector at the same distances shown on all the examples. (The front collector was a straighter shot for the drill then the rear collector). I was mortified to see how thin the casting was on mine at this location. :eek



Oh well, already commited, so I tapped and finished the install. So far it hasn't shot out when I hit the go pedal.



What I am wondering is if the probe only goes ~. 70 inches into the manifold (according to some instructions I scarfed off one of the vendor sites) why are they so durn toot'n long?