Broken intake bolt
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Joined: Feb 2018
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From: Laurel DE
Broken intake bolt
I have a 74 Corvette Stingray that I was replacing the thermostat and one of the bolts broke off on the intake. Can anybody recommend anything to get this out? I have tried easy outs and drilling, all have broken. Any assistance or ideas would be appreciated.
Racer
Joined: Sep 2003
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Find a shop that does EDM (electro discharge machining). Bring them the manifold and they will burn it out.
Le Mans Master
Joined: Jan 2001
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If there is any bit of the bolt left above the surface you can try welding a nut on it...... then screwing it all out.
Race Director
Joined: Sep 2004
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
just drill it out and use a guide to center the bit...does it have a broken easy out in it?
Last edited by bobs77vet; Jun 10, 2018 at 06:42 PM.
Safety Car
Joined: Jun 2017
Posts: 4,786
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From: North Georgia, USA
- You broke off a thermostat bolt in the intake manifold of your 1974 Corvette. You've tried to remove it with drilling and an easy out, and you now have a broken drill bit fragment and/or a broken easy out fragment in the intake manifold of your 1974 Corvette.
- You broke off a thermostat bolt in the intake manifold of your 1974 Corvette. Your past experience with broken bolts is that you have a tendency to break off drill bits and/or easy outs in the broken bolt, and you want to know how to avoid this before proceeding with the broken bolt in the intake manifold of your 1974 Corvette.
If you mean #2, then posting a close up pic of exactly what you have now should help us help you. Also, do you own a torch of any kind? Even a MAP gas torch? Once we see the pic, we can make some other recommendations. Start spraying it with your favorite penetrant now, too. Repeat every few hours or at least daily.
Last edited by C6_Racer_X; Jun 10, 2018 at 07:16 PM.
Race Director
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From: SW Florida.
Generally cast iron and standard bolts have about the same hardness and drilling is no issue. But that is drilling new 5/16ths hole and tapping 3/8ths coarse thread. Extracting the old bolt ain't gonna happen without torches.
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From: Long Island
it's an Edelbrock performance intake = aluminum intake.
Drill out the bolt with a very good drill bit, start with a small bit and use oil on the drill bit / bolt. Buy a Milwaukee or similar bit (s) - not Harbor Freight. Make sure the bit is centered on the bolt.
Then tap the hole using Kerosene or tapping fluid, go slow and keep cleaning the tap.
Use Never-Seize when you reinstall the bolts to control corrosion and make the bolt removeable.
Also put rags / towels in the intake if it's still on the car to collect the chips.
Drill out the bolt with a very good drill bit, start with a small bit and use oil on the drill bit / bolt. Buy a Milwaukee or similar bit (s) - not Harbor Freight. Make sure the bit is centered on the bolt.
Then tap the hole using Kerosene or tapping fluid, go slow and keep cleaning the tap.
Use Never-Seize when you reinstall the bolts to control corrosion and make the bolt removeable.
Also put rags / towels in the intake if it's still on the car to collect the chips.
Le Mans Master
Joined: Apr 2011
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From: Hermosa
If it broke off trying to remove the bolt then it’s seized in there good. Dissimilar metals without anti seize. And that’s bad news.
If you broke it off tightening it then there is hope in getting it out.
With the broken bits in there though they have to cone out first before drilling to a larger hole to get a larger easy out in there.
If you broke it off tightening it then there is hope in getting it out.
With the broken bits in there though they have to cone out first before drilling to a larger hole to get a larger easy out in there.
Racer
Joined: Apr 2009
Posts: 330
Likes: 44
From: Cincinnati Ohio
If you still have broken pieces of the Easy Out or a Drill Bit still in the broken bolt/manifold. See if you can take a very small punch and try to work out the broken pieces. No drill bit is going to drill into pieces of a broken Easy Outs or Drills. The broken pieces are too hard, you have to get them out. A punch may work or else you are going to have to remove the manifold and take it to a shop with an EDM machine to get it burned out. Patience in trying to work it out with a small punch may get the job done. If all the hard pieces are out then progressively drill it out and re-tap the hole.
Tech Contributor
Joined: Aug 1999
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From: At my Bar drinking and wrenching in Lafayette Colorado
Nice, used, perfect condition Edelbrock Performer intakes for small block Chevys sell for about $75 used. They're $139 brand new. If you're going to spend more than an hour screwing around with it, just buy another used manifold and throw away the one with the broken bolt. Stop screwing with it... You've already wasted enough of your time posting this thread to pay for a nice used manifold. (I just sold a never-installed, brand new one in the box for $50). Any shop with a sinker EDM machine is going to charge you a 1-hour minimum (and a 3-hour probable) fee at $125/hr. That would be stoopid.
If you were trying to save a rare LT1 manifold, or a Fuelie manifold, spend the time and money on the EDM process or the machining/drilling/tapping/insert process. Edelbrock Performer manifolds are disposable. Throw it in the trash and get another one.
Lars
If you were trying to save a rare LT1 manifold, or a Fuelie manifold, spend the time and money on the EDM process or the machining/drilling/tapping/insert process. Edelbrock Performer manifolds are disposable. Throw it in the trash and get another one.
Lars
Last edited by lars; Jun 10, 2018 at 11:07 PM.
Safety Car
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From: North Georgia, USA
The least expensive and easiest solution is to just replace that manifold. There's nothing really valuable or rare about it. You'll spend way more than it's worth trying to repair the one you have.
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Nice, used, perfect condition Edelbrock Performer intakes for small block Chevys sell for about $75 used. They're $139 brand new. If you're going to spend more than an hour screwing around with it, just buy another used manifold and throw away the one with the broken bolt. Stop screwing with it... You've already wasted enough of your time posting this thread to pay for a nice used manifold. (I just sold a never-installed, brand new one in the box for $50). Any shop with a sinker EDM machine is going to charge you a 1-hour minimum (and a 3-hour probable) fee at $125/hr. That would be stoopid.
If you were trying to save a rare LT1 manifold, or a Fuelie manifold, spend the time and money on the EDM process or the machining/drilling/tapping/insert process. Edelbrock Performer manifolds are disposable. Throw it in the trash and get another one.
Lars
If you were trying to save a rare LT1 manifold, or a Fuelie manifold, spend the time and money on the EDM process or the machining/drilling/tapping/insert process. Edelbrock Performer manifolds are disposable. Throw it in the trash and get another one.
Lars
By the time I read down to Lars comment I was thinking the same thing
Safety Car
Joined: Jun 2017
Posts: 4,786
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From: North Georgia, USA
As a post script. If you're going to remove the manifold to replace it. Do everything you can not to break off any of the manifold bolts. If this isn't a daily driver, and you can wait a few days to work on it, start applying the penetrant (Liquid Wrench, PB Blaster or home made Acetone/ATF if you know how to use that). Apply fresh penetrant once or twice a day. It won't hurt to tap the bolts with a ball peen hammer when you apply the penetrant.
Have a MAP gas torch available just in case you need to heat things to get them out.
If you do break off a bolt, come here first for advice on what to do about it before you put any tools on the broken bolt.
Have a MAP gas torch available just in case you need to heat things to get them out.
If you do break off a bolt, come here first for advice on what to do about it before you put any tools on the broken bolt.
Last edited by C6_Racer_X; Jun 11, 2018 at 09:08 AM.
Le Mans Master
Joined: Jan 2006
Posts: 6,503
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From: Butler Pa
As a post script. If you're going to remove the manifold to replace it. Do everything you can not to break off any of the manifold bolts. If this isn't a daily driver, and you can wait a few days to work on it, start applying the penetrant (Liquid Wrench, PB Blaster or home made Acetone/ATF if you know how to use that). Apply fresh penetrant once or twice a day. It won't hurt to tap the bolts with a ball peen hammer when you apply the penetrant.
Le Mans Master
Joined: Jan 2001
Posts: 6,672
Likes: 1,363
I agree with Lars here. AND, since you might be trashing it anyway, then you might as well place a nut over it and try to weld it(I'm assuming you can weld and have a welder since that's what I would do...if not, then just toss it) --and then try to unscrew and remove it..... either it works, or you trash it.
Nice, used, perfect condition Edelbrock Performer intakes for small block Chevys sell for about $75 used. They're $139 brand new. If you're going to spend more than an hour screwing around with it, just buy another used manifold and throw away the one with the broken bolt. Stop screwing with it... You've already wasted enough of your time posting this thread to pay for a nice used manifold. (I just sold a never-installed, brand new one in the box for $50). Any shop with a sinker EDM machine is going to charge you a 1-hour minimum (and a 3-hour probable) fee at $125/hr. That would be stoopid.
If you were trying to save a rare LT1 manifold, or a Fuelie manifold, spend the time and money on the EDM process or the machining/drilling/tapping/insert process. Edelbrock Performer manifolds are disposable. Throw it in the trash and get another one.
Lars
If you were trying to save a rare LT1 manifold, or a Fuelie manifold, spend the time and money on the EDM process or the machining/drilling/tapping/insert process. Edelbrock Performer manifolds are disposable. Throw it in the trash and get another one.
Lars
Last edited by carriljc; Jun 11, 2018 at 02:02 PM.
Race Director
Joined: Oct 2008
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From: Long Island
A carbide drill bit works. Sometimes it's about fixing things instead of buying a new one.
Easiest fix is as mentioned - buy a new one, best fix is to repair the old one... it's a matter of perspective...
Easiest fix is as mentioned - buy a new one, best fix is to repair the old one... it's a matter of perspective...
