Intake Manifold Bolt Size
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Melting Slicks
Joined: Jan 2010
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From: Austin TX
Intake Manifold Bolt Size
My dad and I were working on putting the heads back on my '88 after a gasket job and we stripped 8 of the bolt holes. The bolts are fine, the holes are...not in good shape. So I wanted to look into a helicoil sort of kit to tap the holes out and get them fixed. Anyone got the size specs on the bolts?
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My dad and I were working on putting the heads back on my '88 after a gasket job and we stripped 8 of the bolt holes. The bolts are fine, the holes are...not in good shape. So I wanted to look into a helicoil sort of kit to tap the holes out and get them fixed. Anyone got the size specs on the bolts?
You're attempting the heli-coil repair yourself? Look into "timesert" and ask the advice of an automotive machine shop before you make maybe your situation much worse.
http://www.timesert.com/
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Melting Slicks
Joined: Jan 2010
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From: Austin TX
We haven't really decided what we're going to do to fix it. I'm a fairly broke college student and the car's mine so any fix should reasonably come from my pocket so I'm trying not to spend a lot. The threads are pretty obliterated. Realistically, we're probably going to need to take the heads back off to make sure it's clean. Now that I have the thread specs I can look up time-sert and helicoil prices.
Thanks for the quick reply braeburn
Thanks for the quick reply braeburn
Team Owner
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Cliff - He asked "intake" ? INTAKE to CYLINDER HEAD 3/8 - 16 and I believe are maybe torx. 3/8-16 I believe is consistent through end of production LT1/4 builds.
Plenum hardware is M8
Plenum hardware is M8
Last edited by WVZR-1; Jun 15, 2013 at 05:51 AM.
Burning Brakes
Joined: Nov 2006
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From: Portsmouth Virginia 396LT4 435RWHP/400RWTQ Best so far 11.26 @ 123mph
Depending on how much thread root is left in each hole, an other option would be to tap the existing holes to 10mm which is only about .020" larger than a 3/8" bolt and buy some new metric 10mm flange head bolts. This should give you enough bite with the bolt to torque it down properly. Done this a few times in the past. If all existing threads are visibly gone, then an insert would be needed.
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Team Owner
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Depending on how much thread root is left in each hole, an other option would be to tap the existing holes to 10mm which is only about .020" larger than a 3/8" bolt and buy some new metric 10mm flange head bolts. This should give you enough bite with the bolt to torque it down properly. Done this a few times in the past. If all existing threads are visibly gone, then an insert would be needed.
Burning Brakes
Joined: Nov 2006
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From: Portsmouth Virginia 396LT4 435RWHP/400RWTQ Best so far 11.26 @ 123mph
Metric Socket head/Allen head cap screws with a flange head are also available thru McMasters Carr if bolt head access using a box wrench is a problem on the manifold.
Team Owner
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Besides the M10 isn't a quality repair, it's "rigged"! Attempting anything other than the correct fix could likely end up deeper into the OP's pocket.
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From: Anaheim CA
I did look in my notes and all I saw were the plenum bolts, so that's why I thought M8.
Sorry for the incorrect info.
Burning Brakes
Joined: Mar 2010
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From: Providence RI
Do the job right the first time. The heads do not have to come off. Use plenty of grease on the drill bit and go very slow. Same thing with the tap. Take your time and do all 12 of the bolt holes.
Every bolt hole on my superram has been helicoiled minus the 64 bolts which hold the top cover onto the plenum. I have never used time serts but I have always heard great things about them. Also, you do not have to deal with that "Tang" at the bottom which could cause you trouble regarding where it falls when you break it off.
Good luck and keep us posted.
Mike
Every bolt hole on my superram has been helicoiled minus the 64 bolts which hold the top cover onto the plenum. I have never used time serts but I have always heard great things about them. Also, you do not have to deal with that "Tang" at the bottom which could cause you trouble regarding where it falls when you break it off.
Good luck and keep us posted.
Mike