1/8" drill bit broke off in manifold hole - The 1947 - Present Chevrolet & GMC Truck Message Board Network

DADS71 · 09-01-2009, 09:30 PM

replacing stud bolts on 402 big block exhaust manifold. Any tricks to drilling out broken off bit in exhaust manifold hole it had to be the hole that didnt go all the way through ,just tapped into manifold.

IndianaK5 · 09-01-2009, 09:39 PM

Dads71,
Dealing with these old manifolds can be a pain. I just pulled and replaced the studs on my manifold and had to drill all three out on one side. You're almost guaranteed a struggle.

were you drilling out to tap size, or were you getting the pilot hole started?

Zach

ps i'm in princeton, in. Nice to see someone from the area.

*vegaschevy* · 09-01-2009, 09:58 PM

Is it a cheap carbon type bit? if it is you can heat it up till its really hot and then shoot it with cool air. It will shatter into small pieces.

DADS71 · 09-02-2009, 05:15 AM

Hey indiana k5 this was my pilot hole the stud is 3/8. never heard of heating it up and shooting air on it worth a try ,the bit isnt a cheapo I think index was 150.00 or so thanks for info.

cdowns · 09-02-2009, 07:36 AM

i always just take a drift punch and large hammer to breakup drill bits

big_al_71 · 09-02-2009, 08:00 AM

I would use an easy out with lots of patience...

*2tons of fun* · 09-03-2009, 01:40 AM

weld a nut to the stud, the heat will help release the stud/mani grip.

if all else fails i have some original 70 402 no air tube manis that i dont need.

El_Crnicero · 09-03-2009, 01:53 AM

X2
I broke the old bolt heads when I rebuild my motor. they swelled inside the manifold sleeve. I had to heat them up and pry on the manifold to get clearance to stick a saw inbetween the head and the manifold and cut the bolts by had... what a pain that was.

Welding a nut is awesome if you have the clearance.

09-01-2009, 09:30 PM	#1
DADS71 Registered User Join Date: Jan 2009 Location: EVANSVILLE INDIANA Posts: 54	1/8" drill bit broke off in manifold hole replacing stud bolts on 402 big block exhaust manifold. Any tricks to drilling out broken off bit in exhaust manifold hole it had to be the hole that didnt go all the way through ,just tapped into manifold.

09-01-2009, 09:39 PM	#2
IndianaK5 Registered User Join Date: Jul 2009 Location: Princeton IN Posts: 11	Re: 1/8" drill bit broke off in manifold hole Dads71, Dealing with these old manifolds can be a pain. I just pulled and replaced the studs on my manifold and had to drill all three out on one side. You're almost guaranteed a struggle. were you drilling out to tap size, or were you getting the pilot hole started? Zach ps i'm in princeton, in. Nice to see someone from the area.

09-01-2009, 09:58 PM	#3
vegaschevy Account Suspended Join Date: May 2009 Location: las vegas nv Posts: 1,493	Re: 1/8" drill bit broke off in manifold hole Is it a cheap carbon type bit? if it is you can heat it up till its really hot and then shoot it with cool air. It will shatter into small pieces.

09-02-2009, 05:15 AM	#4
DADS71 Registered User Join Date: Jan 2009 Location: EVANSVILLE INDIANA Posts: 54	Re: 1/8" drill bit broke off in manifold hole Hey indiana k5 this was my pilot hole the stud is 3/8. never heard of heating it up and shooting air on it worth a try ,the bit isnt a cheapo I think index was 150.00 or so thanks for info.

09-02-2009, 07:36 AM	#5
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: 1/8" drill bit broke off in manifold hole i always just take a drift punch and large hammer to breakup drill bits __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

09-02-2009, 08:00 AM	#6
big_al_71 Registered User Join Date: Jun 2008 Location: South Florida Posts: 11,375	Re: 1/8" drill bit broke off in manifold hole I would use an easy out with lots of patience... __________________ Get your facts first, and then you can distort them as much as you please!!!!!. Sylvester's build thread >>>http://67-72chevytrucks.com/vboard/s...ht=big+rebuild

09-03-2009, 01:40 AM	#7
2tons of fun Account Suspended Join Date: Jan 2009 Location: galt ca, Posts: 749	Re: 1/8" drill bit broke off in manifold hole weld a nut to the stud, the heat will help release the stud/mani grip. if all else fails i have some original 70 402 no air tube manis that i dont need.

09-03-2009, 01:53 AM	#8
El_Crnicero Registered User Join Date: Jul 2008 Location: Kirkland Wa. Posts: 25	Re: 1/8" drill bit broke off in manifold hole X2 I broke the old bolt heads when I rebuild my motor. they swelled inside the manifold sleeve. I had to heat them up and pry on the manifold to get clearance to stick a saw inbetween the head and the manifold and cut the bolts by had... what a pain that was. Welding a nut is awesome if you have the clearance.



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