The correct drill size is a letter "R" by the way. I like to make a pilot hole first so the hole is straight and parallel. Use plenty of cutting fluid, and as mentioned, creep up on the tap - put the fitting in, tap a little more, put fitting in, tap a little more, until you hit the correct depth. Be sure to start the tap at exactly the same angle as it was drilled.

 

If you haven't done it yet and need assistance give me a shout, would be happy to help walk you through it. Worst case I can find a reason to end up in your neck of the woods. If you don't have any cutting fluid don't worry, cast iron is free machining - you'll be fine without and won't have a gummy mess to boot.

 

For 1/8-27 NPT that is. 7/16" drill for 1/4-18 NPT. It all depends on what fitting the OP wants to go with.

 

The only way to really screw this up is to over tap the hole so the fitting will not tighten up. Run tap in a little way and check the fitting. You want fitting to get snug at about 3/4 of the way in. (Ideally, threaded all the way through the manifold material).

A LOT of people stress about the drill shavings/chips. THIS IS A NON-ISSUE. Any debris left inside the manifold will be gently swept out and past the turbine wheel at startup and cause no damage. The gas velocity is low and the cold turbine wheel is not easily damaged - especially at low RPM. Using grease on the tap or cutting oil on the drill is a BAD IDEA if you’re the worried type. This grease will lock those little bits down so they can’t move easily until the grease burns and/or the engine rpms (and subsequently turbo shaft rpm) are much, much higher.

The cast steel manifolds drill super easy. The biggest concern is adequate eye protection so you don’t end up with metal in your eyes.

I used to have a pile of glow***** gauges I took out of trucks after they failed. There may be lower quality gauges out there, but I haven’t seen them yet. Good luck!

 

I do it the way you described. I’ve only installed a few dozen like that that though....

 

I tried to send a rep your way sir, but I am still in jail. That is a very generous offer and greatly appreciated by many. If someone would be so kind to try and rep IDI-Charlie on my behalf, I would appreciate it!

That is reassuring to hear. I knew I had not messed it up at all because the EGT probe has been securely mounted for several years now. I didn't know there were differences in how a tap is used based on metal type, but it makes sense. I think being overly cautious on the softer cast iron is not a problem, just maybe a bit OCD.

Thanks for the vote of confidence Jason.

@afonda , did you get the project done? Still working on it? How did it go or is it going?

 

I've probably tapped a 1000 pipe taps of various size in various materials. Show my one CNC machining center or turning center that, that taps a pipe tap...or any tap for that matter, in that method. Tapping is unique is that the only variance in depth of cut is a minor amount on the tap drill....and pipe tapping also can use a tapered reamer...which are seldom used in the smaller sizes. So the feed rate is a fixed value based on the pitch of the thread. You can vary the cutting speed (rpm).

Pipe tapping in a production environment can be a pretty suck process.

 

@Dan V , I am not questioning your ability, skill level or experience, simply trying to learn from what you have told us. With that said, I followed the tapping instructions that were provided with the EGT probe from ISSPRO and some visual aid advice from YouTube videos like the one I have linked below. At 2:40 in the video is where the creator demonstrates forward, then back, then forward, then back. Perhaps this is due to the type of material the tap is threading?

I get it though, this is a YouTube video and in my days of service I would not have gone to YouTube for advice on any of the tasks we were required to perform or any missions that needed to be accomplished.

Now, I am fully aware that a CNC machining center or turning center does NOT use YouTube as a point of reference. Although, for people that make up most of the FTE community, people like you and videos like this are the resources we have available to us. Again, not questioning, just trying to learn...

 

Late to the party here everyone. Here's my .02 on tapping and I have tapped lots of holes over my 34 years working in the shop.

Tapping/Taper pipe taps can be tricky sometimes.The most common problems for most people are not drilling the hole as perpendicular as possible or they go too deep and the pipe fitting doesn't tighten up enough-this is usually most noticable when the pipes are carrying a liquid of some sort. Most times when we tap by hand in the shop we go 3/4 to 1 turn and then back up half a turn to break the chips. We also use tapping oil but it is dependant on the material being tapped. Cast iron usually breaks into little chips due to it's material makeup. I have done exhaust manifolds for others and I have used grease on the tap and backed it out and cleaned the flutes numerous times to remove the chips and I keep on doing this till I get to the proper depth.

In the shop we quite often place the pipe tap/regular taps in a drill press and power tap down until the pipe tap is 3/4 of the way in. This does save a lot of time when doing multiple holes.

I never knew what Jason mentioned about the intake side/debris left inside the manifold will be gently swept out and past the turbine wheel at startup and not causing damage so you learn something new every day.

Rob

 

@Sous Ok, I man enough to admit when I wrong. I did find a video of a cnc machine tapping similar to the manner which you describe.
https://www.centroidcnc.com/cnc_rigidtapping.html

But, I'd venture the manner I which which you practice, or have seen, is different than the attached video. (For those not watching the video) in the video the operator talks about clearing the chips as there is only .050 from the bottom of the hole to the last thread. (and is using an air blast to clear the chip). They are talking about about blind hole are trying to prevent chip packing at the bottom of the hole.

I have done a bunch of thread milling, which is a 3 axis procedure. It's like witchcraft.

 

Got it done. All went together well...

EGTs... what is normal? i see they are all over the place. I ran it hard with high boost and the temp got up to 1300. But I see they are normally running 400 to 800..

Thanks.

 

That sounds about right.

 

running at a sustained 1300 is bad for the engine, if you reach the higher temp just briefly it is okay though

 

Yeah... it's not doing that.. It's actually hard to get it over 900. Idles about 200 to 300, and vairies from there up to about 800 depending on what I'm doing. I have not towed anything yet to see how that affects the EGT. I'm wondering what will happen when towing like 5000 lbs or more up and down hills. Or, driving over the sand like I do a lot when surf fishing in Cape Hatteras.

Thanks.

 

Good advice from all. The gauge install kit should come with directions and drill bit/tap size. Get one of these from Harbor Freight and make the job 100 times easier and less prone to screwing it up.

https://www.harborfreight.com/t-hand...nch-97633.html