Advice for performing heli-coil upgrade on the exhaust manifold studs???

Mo87NA

1987 7M-GE & 1991 7M-GTE
Mar 31, 2005
778
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Upstate NY
Wha'ts going on guys?

I recently purchased the Driftmotion heli-coil exhaust stud kit. Although I have the basic concept down, and I've done similar things in the past, I would like to get your feedback/advice for performing this upgrade. I am going with the 7/16" studs.

Unfortunately, this will be done with the engine still in the car. I do have a 90 degree drill that should make things a tad easier.

Anyway, any advice or information is greatly appreciated.

Thank you in advance.
-Mo
 

Poodles

I play with fire
Jul 22, 2006
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Dunno if he found a supplier for the shorter drill bit, but I ended up cutting the drill bit shorter (not the shank, but actual cutting part) and resharpening it with a Drill Dr. Full size drillbit won't fit when you go for the back holes, so it's required. Other than that, it's pretty straightforward.
 

grimreaper

New Member
Jul 2, 2008
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A cordless 90* drill with a short shank bit worked perfectly for me. Use a socket extension next to the hole to get an idea of how straight your drill is. You will most likely have to open up the lower exhaust manifold bolt holes and gasket holes as getting them all straight and true is near impossible in the car.
 

Mo87NA

1987 7M-GE & 1991 7M-GTE
Mar 31, 2005
778
8
18
38
Upstate NY
Poodles, thanks for the help.

I remember he offered a kit with a stub 7/16" bit. This kit does not have it. I'm sure I can find a shorter one somewhere.

Is there a particular type/style drill bit I need to use, i.e.) metal composition, thread, etc?
 

Poodles

I play with fire
Jul 22, 2006
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Good luck finding the bit, it was cheaper for me to just cut and use the drill doctor (it's a good tool to have anyway since as long as there are flutes left on the drillbit it can be resharpened and save you money)
 

Koenigturbo

Active Member
Oct 4, 2006
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Pooldles whats the concept behind cutting the bussines end of the drill verse's the Shank, to me cutting the shank makes sense.

O.P. when I did mine, I stuffed a lintless rag in the ports along with a vaccume to suck up the shavings. Or just tape the ports closed. I know, I'm Stating the obviuous, the vaccume,.. rendundant?? not to me it's not. Dont forget the "Lock tight"
 
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whitemike

Banned
Aug 30, 2009
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I recently did this in-car. It was fun.

A few words of advice..
-Obviously, try your hardest to keep the drill straight. It may seem like "duh" but having to position your body and the drill at awkward angles to get it in the tight space - it may become an issue.
-I used a lot of lubricant (WD40) while drilling, not sure if that's everyone's first choice, though.
-I believe the heli-coils should be flush with the head, NOT recessed as shown in the picture. Hopefully someone will chime in with more info though!

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Poodles

I play with fire
Jul 22, 2006
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As there are already holes there, the drillbit will self guide for the most part. It's when you tap the threads that you have to be super anal about being straight.

I'm not saying to be lazy, but don't sweat it too badly as the only way to get it perfect would be to pull the head and use a drill press.
 

Mo87NA

1987 7M-GE & 1991 7M-GTE
Mar 31, 2005
778
8
18
38
Upstate NY
Thanks for the help guys. I'll let you know how it turns out.

Any other advice is welcomed.

-Mo
 

Cz.

CAR > FAMILY
Mar 31, 2005
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Seattle, WA
Don't go too deep or you might hit the coolant jacket.
When I did this on my old motor I was really careful about it and spent an hour or two doing one stud. As I went to put on the manifold another stud came out and I had to helicoil that one too. Took maybe 15 minutes that time. Both held fine. Once you get the hang of it it's not that tough.
 

shaeff

Kurt is FTMFW x2!!!!
Staff member
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Mar 30, 2005
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Stop letting little Hercules work on your car. Then you won't strip stuff... :sarcasm:













<3 you Ernie!