I Drilled a Hole in my Exhaust Manifold

[bdaniel]

Well I did it. I drilled and tapped a hole in the exhaust manifold for the pyrometer.

It was actually really easy. I did the axle grease on the drill bit/tap routine and used a small magnet to get any metal that escaped the drill bit and tap.

I had to run the tap much deeper than I thought I would. I actually got concerned because the thermocouple still would not start in the hole after several turns of the tap in the hole.

So I grabbed a 1/4" piece of mild steel, drilled a hole in it and tapped it for the thermocouple. This gave me some ideal how far the tap would have to go.

So a word of advice. If you have never used an NPT tap, practice on a piece of steel first.

Only thing left now is the Auto trans temp sender. I have the brass "T" and compression fittings. Probably attack that this weekend.

Bobby



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2000, Driftwood, 2500, automatic, 3. 54, 2WD, LWB, SLT, Quad Cab, most of the options, Grover air horns, tow 5500lb 28'x8' Aerolite TT and two small boys.

 

[Lurch]

Wasn't nearly as bad as you thought it would be, was it? Congratulations.

 

[Guest00]

Let the bombing begin!! #ad
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2K, 2500,Laramie,Quad,4x4,3:54LSD,auto,reese 15k 5th slider, EISLEY BULL BAR,WESTIN NERFS, TA's,9000's, DD2's,Bully Dog Boost & elbow, ISSPRO pyro & boost, Turbo Lifesaver, JARDINE 4", DTT VB,TC and COOLER, PAC BRAKE, MAG HYTECH TP& DC, onboard.
pullee #1 26' Arctic Fox 5th
#2 22' car hauler w/ 76 Pinto 392cid or 68 Cyclone GT Cobra Jet FB
NRA-LIFE,VFW-LIFE,SASS



[This message has been edited by JNutter (edited 01-17-2001). ]

 

[Deezal Man]

Never tried it, but one of the mechanics, (who I graduated with in high school) at DC told me to idle the engine while drilling. He said the exhaust will "blow" out any shavings created from drilling. He thought the grease was a good idea as well.

Sounds like it would work, what do you guys think?

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98. 5' 24v 2500 Auto/3. 54 4x4 SB QC 285-75-16's on Alcoa's. Everything but leather. PIAA 1200's, AMSOIL dual filter relocation system, Smittybuilt Stainless Steel Nerfs, Rhino Liner(Junk), K&N air filter(For Sale)15 year AMSOIL dealer. Time permitting, Soon to include Ultra-lite Pyro,0-50lbs boost, Trans temp in the pillar. Rancho 9000's with in cab adjustment.

 

[MikeR]

Deezal,
I have drilled a bunch of holes now with the turbos left on,and it can't get any easier using the grease-covered drill bit trick. I don't think I'd run the engine while doing it because I wouldn't want to accidentally want to touch a hot manifold or turbo. Also I think it would be hard to keep the drill bit centered with an engine that's shaking back and forth.

-Mike

 

[Pogodually]

I drilled the hole and tapped it for EGT probe without engine running. Just used a heavy coating of grease and a heavy duty vacuum near the bit as we drilled, then tapped. Was much easier than I thought. Worked great.

 

[Stab]

Apparently you guys have never priced a new or rebuilt turbo! Got more balls than I do! I have never, and never will drill a manifold with the turbo on!

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Owner: Stabco Repower-stabco@bbc.net The turbo housing guys. '89, CC, SB, 5sp, 3. 54, 16cm2 housing, intercooled, maxed fuel, KN, Banks exh w/muffler, Horton fan clutch, Autometer liquid filled gauges, Accessory tach option, 100% Dyna-Mat, Borgeson steering shaft, Firestone air bags, Chrysler V-twin air comp, 2. 5" lift, Rancho Shocks, Alcoa LTS wheels (recalled), BFG 255/85/R16 MTs (33. 3")

 

[R.ebel]

I'll second Stab's comment.

I drilled and tapped mine using grease, then I went after the chips with a magnet and vacume. When it was all done I just did'nt feel good about the possibilities... and the voice in the back of my head that kept saying "I sure would'nt take the chance". So off came the turbo and low and behold there were a few errant chips (maybe a dozen) that would have gone through the turbo if I had'nt removed it to check.

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1997 2500 Ext Cab 4X4,5 spd,3. 54's,Pac brake,Rancho 9000's,Centerforce clutch,K&N airfilter,Missing
Cat,Isspro gauges,TST #11 plate (280hp/680tq),AFC medium spring and Jardine 4" exh.

 

[illflem]

I'm with Stab also,The turbo is easy to take off and while you're at it you can add a bigger one. Having the turbo off makes it much easier to set the depth of the thermocouple.
I've always removed all metal chips but have wondered how likely they are to cause damage,it seems like the worse that could happen is that a chip could wedge between the housing and fan and stop it,but even that doesn't seem too likely. Has anyone ever had a problem attributed to metal chips?

 

[Scooby]

Yeah, that idling trick might work on a Lexus or something, but I wouldn't try it on my Cummins! #ad

 

[Dennis Garrett]

Any debris left from drilling the exhaust manifold goes out the exhaust side of the turbo, not the intake. Any metal dust & carbon will blow out with the exhaust & won't bother the turbo on that side. The intake side would be a different deal. The exhaust side is used to dealing with red hot exhaust gasses & carbon particles. If the drill bit broke off or something, it might get caught in the blades, but not drill dust. As long as you grease the flutes on the drill & tap, pick put any obvious pieces & shavings with a magnet, you'll be OK. None of that stuff can get to the bearings either.

[This message has been edited by Dennis Garrett (edited 01-18-2001). ]

 

[R.ebel]

I believe the clearence between the turbine wheel and housing is very tight, any nicks or damage in this area will degrade your turbo performance. #ad

 

[MikeR]

Right Dennis,

After cleaning the big shavings out,if there are any shavings left,they are not going to come in contact with any bearings or bearing surface.

-Mike

 

[Jim Guidry]

Did mine with the turbo on, no problem in 17K miles!

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'96 Regular Cab, 116. 5K, SLT 2WD auto 3. 54, Vista topper, Pillar-mounted Autometer Boost/Pyro, transmission temp and oil pressure guages under dash, starwheel spun

 

[Stab]

I will state the famous Robert Patton quote:
"You are your own warranty station!"

I don't think many of you realize the importantance of balance in a 100,000 rpm piece of fine metal. One little chip, maybe a tenth of an ounce or less on the exhaust wheel spining that fast and you get premature wear. Just don't blame it on Chrysler, Holset or an after market vendor like myself. I can't afford to have something like this come back on me, so I do it the correct way: Pull the turbo! Takes what? 15-20 minutes longer?