There are two ways you can drill and tap the exhaust manifold for a pyrometer/thermocouple.

The first is to remove the exhaust housing from the engine and, the second is done with the exhaust manifold on the engine.

If you choose the removal method, you’ll need to have gaskets on hand for the install afterwards. It is also more work doing it this way but some are more comfortable with this method.

No matter which method is used read ALL THE INSTRUCTIONS

FIRST!!!!!

If you use the “on engine” method or the removal method the locating/drilling/tapping process is nearly identical, here is how you should go about this...

1) Most commonly the rear runner of the manifold is used for the drilling/tapping location.

2) Locate your center punch position ¾” back from the turbo/manifold flange and, centered between the firewall side of the manifold and the center “web” of the manifold.

3) Using a 7/16” bit, grease it well using heavy axle grease. Begin drilling.... after a few moments, pull the drill bit up, remove any fillings and re-grease then, continue drilling. Continue with this process until you “break through”. At this point remove the drill again and using a mechanics pencil magnet, “fish” for any small bits of shavings that MAY have entered the manifold. Spend a few minutes with this step. Take your time and try to make sure you’ve left little or no bits in the hole. Once you’ve done this you can be assured that any tiny bits that MAY have been left will not cause any damage to the turbo.

4) Once you’ve cleaned out the hole with the magnet you are ready to begin the tapping process.

5) Using a ¼” NPT pipe tap grease it well and use the same tap/grease method as the drilling process. Be sure to keep the tap as perpendicular as possible, you don’t want to tap the hole off center.

6) Do not tap too deep. You should check the depth of tap. The probe mount should turn in approx. 3 ½ full turns. That is all that is required. You are trying to make sure that it is a snug fit and the probe tip is extending into the exhaust stream approx. ½ the holes’ depth. (about ½ - ¾”)

7) Once you feel you’ve got it right, apply a touch of anti-seize compound to the threads and install the pyrometer probe. Snug it down and you are done.

If you remove the turbo to do this installation it would go like this:

1) Loosen the turbo oil drain tube at its rubber hose clamp near the engine block.

2) Loosen/remove the turbo outlet/exhaust down-pipe V-Band clamp.

3) Make sure you are supporting the turbo and remove the 4 – 15mm nuts that hold the turbo to the manifold. Don’t forget to have a turbo gasket handy.

4) Once the turbo is removed, place a good-sized rag into both ports of the exhaust manifold. Tuck it in so that when you drill through the manifold the rag doesn’t get snagged on the drill bit and, any fillings are prevented from falling back into the exhaust ports on the engine head.

5) Use the same drill size (7/16”) and grease well as noted in previous example. The only difference is you don’t have to remove the bit. Just drill right through.

6) Once you’ve got your hole drilled, it’s time to begin the tapping process.

7) Again, you can use some grease or anti-seize on the ¼” NPT tap to make it a bit easier to complete this step.

8) Once you’ve determined that the tapping is deep enough (about 3 ½ turns on the pyro mounting stub) remove the tap, clean the area of shavings and carefully remove the rag pulling all the shavings out as you go.

9) When that is done, thread in your pyro probe and snug it down. It should

protrude roughly ½”– 5/8” into the exhaust stream but it SHOULD NOT

TOUCH THE BOTTOM OF THE MANIFOLD CASTING OR DAMAGE WILL

RESULT!

10) As you install the turbo, try to make the connection between the turbo oil.

drain tube and it’s rubber hose connection first, then slide the turbo onto the

mounting studs on the manifold

11) Tighten the hose clamp on the oil drain tube, then tighten the turbo

mounting nuts snug.

Ok, at this point you should go back and review the steps you taken and confirm them one by one. When you’ve done that and you’re certain all is well, it’s time to fire the engine up.

All you should do at this point is start the engine and let it IDLE ONLY for a few minutes. Any tiny bits of shavings will blow harmlessly out and down the exhaust down-pipe.

Below is a picture of the relative parts/locations for your install.

Drill a 7/16” hole and use a ¼” NPT tap.