Little by little I am getting things done here. Next project is gauges. I will be drilling and tapping the exhaust manifold for a pre-turbo pyrometer sensor. Having not done a lot of this, how about some advice.

How hard is the manifold? Will I need a special drill or tap?
Do I use teflon tape on the sensor threads?

thanks in advance, you guys are great. This board just proves that you can teach an old dog new tricks!

Rocky

 

If I remember right I used a 11/32 or a 5/16 bit and a 1/8 npt tap, remember there is a divider in the center of the manifold, so drill it on the back side

No thread tape just a little anti seize

 

when i drilled mine i drilled mine almost all the way trough then put greese on the drill bit to catch any shavings that could fall in and when i tapped it i did the same thing. i drilled the hole on the back side of the manifoled where the back 3 cylinders come together because #5 cylinders is one of the hot ones. as for the pyro i just put it in with nothing on it

 

There is a center divider in the manifold, so don't drill right in the middle. Offset your starting point 3/4'' or so toward the firewall. This'll pick up the temp od the rear 3 cylinders, which tend to get the warmest. Drill slowly and grease the drill bit to catch the shavings. Same with the tap. Run a magnet around in there before you install the probe to get any lost fragments. Run the tap in a little and then test the probe fitting. If you go too far (like I did...) the fitting will fit sloppy since pipe threads are tapered. It took longer to type this then it does to do the work


Oh, Welcome to DTR!!!

greg

 

I did mine last year, Easy. I consulted with Enterprise Engine first (local dodge perf. shop). They stated they use a right angle drill and never took off the manifold, can't remember them saying about the grease. They stated they do it all time and have never had a problem. The amount that gets in there is minimal and the size of it will not hurt anything, just blow right out, they said. I trusted their experience, used my dewalt 12v cordless and it just cleared enough room to drill. I went slow, most of the shavings came out on the bit, installed with anti seize and fired it up. No problems.
I am not saying i recommend you do it this way, just saying I was successful and personally I wouldn't be afraid of hurting anything.

 

Use grease and a pen magnet afterward.

 

I drilled and tapped mine with the engine running and all the chips just blew out the hole. Start with the engine cold and wear safty glasses, it's amazing how far and fastthe chips blow outeven at an idle.

 

I just did mine last weekend and it is not that big of a deal. That part was the hardest for me was when I was about to cut through the bit caught and almost threw me overboard.

 

I did mine with the engine running becuase I didn't want to take the manifold off. Have a picture of it somewhere in this web site. Cast iron is soft, but still take your time -broken drills (or taps) would ruin anyones day. Step drill. Use grease. Keep the drill and tap clean often. Go slow with the tap backing up often. Don't let the engine heat up the bit or tap too much. Shut it down and come back later when cool in between each step. I wouldn't use teflon tape. Anti-seize is the high temp application stuff to use for install.

As far as the location stay off the integral webs. Some cylinders/ loacation may run a little hotter than others, but not so much as to really make a difference unless you are doing performance testing or R&D.

It only took all of two hours, and I was way cautious to prevent things from breaking.

 

I did engine running too. No prob's.

JP.

 

I'm not understanding why it's better to drill with the truck running. won't this send shavings into the turbo?

 

its best to remove the turbo but if you leave it on, then with the truck running the exhaust pressure in the manifold pushes the shavings out of the hole being drilled.

 

I drilled mine with the engine running. The exhaust back pressure will blow the 'chips' out of the hole as soon as you break into the manifold tube. I drill until almost through the manifold and then start up the engine. I have done this on many different engines.

 

If you want to be really safe then undo the 4 studs holding the turbo to the exhaust manifold, pry the 2 surfaces apart and put in a piece of cardboard inbetween the two. Drill and tap the manifold then use a pry bar to keep the turbo and manifold apart (leave the cardboard in place), dont need a bunch of room just a little bit, start the truck, let it run for 1-2 sec then turn it off and put the 4 studs back in. The exhaust will blow out all the metal shavings, oh and I don't use and grease or anything, just a bit of cutting oil for the tap.

Oh and as for the size, it varies with the pyro kit, I had to use a 7/16 drill bit and a 1/4 pipe tap.