Another question - pyro install

[MacHaggis]

Has anybody ever measured how thick the exhaust manifold is in that spot behind the web that catches #5 and #6.



I'm having the idea I want to work my way up through two or three straight bits for the pilot hole beofre I tap it out for the NPT fitting. Just to minimize the shaving issue, it would be nice to only have to break through on the last straight bit. I'd have it greased up like the tap. Being a cast piece, I'm sure it varies, but if anybody has ever measured it . . .



I'm also wondering if my failing memory serves correct that the exhaust manifold is steel rather than iron. I'm sure it'll be brittle in any event and will treat it like cast iron, but wondering all the same.

 

[Cattletrkr]

How is using multiple bits going to minimize the "shaving issue"? Use one small bit for a pilot if you need it and one bit for the hole. Bigger chunks are not a problem. I've done a whole 2 of them w/o any probs. A "Drill Doctor" is money well spent. One sharp bit will make way less shavings then a few dull ones.

 

[RMarkey]

I did the one pilot bit, then the big one, then a telescoping magnet to get out all the shavings, the the tap, them more magnet shavings. I was suprised how many shavings actually went in there. Everyone says they don't hurt anything, but I figured if I can take the out, why not do it. There were more shavings from the tapping than the actual drilling. If you're not going to magnet them out, or can't if you are right over the down tube to the turbo, Id think the less you push the bit, the smaller the shavings. Better than big shavings maybe?

 

[BigGunZ]

I recently installed my thermocouple. The manifold thickness is approx. 1/4 inch. I used a single bit. It drills easily so a pilot is really not necessary. I didnt grease the bit until it was almost ready to punch through and looking back, I don't think greasing it is necessary... makes less of a mess. I greased the tap just for lubrication and I had to go buy a magnet small enough to fit the hold... it still didn't fit well so I used the back end of a drill bit with a magnet held to it to get the shavings out. It was actually a fairly easy job... just a little nerve racking taking a drill to a $7k motor.

 

[rjones]

My opinion the fine shavings that drop threw wont hurt anything..... I used a 21/64 bit drilled right threw no problems then I too stuck a magnet in the hole but the larger shavings stay outside the manifold... ... .

 

[Buffalo]

It isn't that hard to loosen the bolts holding the turbo to the manifold, lowering the turbo, a bit, cut a piece of cardboard (from a cereal box) & place it in the opening between the turbo & manifold.



Then do your drilling/tapping. When you are done, blow the shavings off the cardboard, pull it out & tighten up the turbo bolts, & you're done & don't have to worry about getting anything in the turbo.



I am no where near talented enough to be a mechanic & this is the way I did it. It really wasn't that hard. This is the first time I had ever drilled & tapped, anything.



Just before I drilled/tapped, a member, here, wrote in to tell us not to tap in too far (3 to 3-1/2 turns of the pyro), otherwise the pyro could back up against the back of the inside of the manifold. Boy, was I glad to have that information!!! I would have tapped in all the way.



BTW, I jacked up the front, right corner of the truck, removed the wheel & the plastic wheel-well liner. This gives you a straight shot at the junction of the manifold and the turbo. Makes it easy to drill the manifold just above the turbo.



One of the members, here, mentioned he was worried about making a mistake & screwing-up a $7000 engine. I know, exactly, how he feels. With my lack of mechanical talent & tools, I was damn scared to take on this project. With the helpful suggestions from TDR members, the job was really not bad, at all. Wouldn't be much of a project, at all, now that I've done it once. I just didn't want to go through life without trying, once. Glad I did.



Hope my experience helps some of you that have never done this installation.



Joe F. (Buffalo)

 

[MacHaggis]

"How is using multiple bits going to minimize the "shaving issue"?



I had in mind cutting a hole most of the diameter just short of breaking through, making most of the shavings no sweat, then cutting the last 1/16 or so of the diameter to break through and greasing the end of the bit like I would the tap. And, I agree, there's only a few things worse than a dull drill bit, and even fewer things any better than a sharp one.



"It isn't that hard to loosen the bolts holding the turbo to the manifold, lowering the turbo, a bit, cut a piece of cardboard (from a cereal box) & place it in the opening between the turbo & manifold. "



Buffalo -- I've got that in mind too. Probably double up some duct tape on the upper side to hold it in place. And thanks for the reminder on not pushing the tap all the way through. A couple others elsewhere tipped me off to that.



I'm of the general mind that the shavings will be on the exhaust side of the turbo and as long as I do a reasonable job of cleaning them up and any that I miss will be fine enough, they'll do little harm, if any at all. I'm not exactly belt and suspenders in life -- just tryin' hard not to mess up.



Thanks to all!!!