bad news everyone!
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bad news everyone! I just got my new motor together and the threads on the head for my roller rockers failed...(in the head not stud). They didnt even crosthread, just came out the head on the bolt. Never went over 22pounds of torque... I have yellow tera rockers and they use bolts.. so my question is can i tap it out bigger and use a stud and shim it or do i just have to helicoil it? Open to suggestions and experiences. It is the stock bolt size for ls1 heads. Thankyou.
Hmmm...that's weird.
Take it to a machine shop and have the hole(s) helicoiled. Don't do it yourself. With a seat and guide machine, or possibly even an end mill, they will be able to get the angles perfect, rather than eyeballing it with a hand held drill and a tap.
There are plenty machine shops here in the Houston area for you to choose from. Robert at LME is pretty sharp, and could probably get them back to you the quickest.
Take it to a machine shop and have the hole(s) helicoiled. Don't do it yourself. With a seat and guide machine, or possibly even an end mill, they will be able to get the angles perfect, rather than eyeballing it with a hand held drill and a tap.
There are plenty machine shops here in the Houston area for you to choose from. Robert at LME is pretty sharp, and could probably get them back to you the quickest.
You can get studs at McMaster-Carr. If you use a regular stud mounted rocker stud it will have a flange that contacts the head and the rocker pedestal won't sit correctly.
How long were the bolts you were using? Are you using shims on the rockers?
How long were the bolts you were using? Are you using shims on the rockers?
You want to do a stud mount rocker setup? Comp has a kit, but I don't think it has the larger diameter threads going into the head. It's not really necessary, though, especially if you helicoil it.
Dude, helicoils are used in Boeing aircraft as well as space shuttles, I think it is okay to use in an LS1. I'm not saying they are any better or worse than Keenserts, but helicoils are just fine.
Last edited by KCS; Nov 27, 2009 at 03:52 PM.
Trending Topics
Keenserts are a good approach in some cases, but they are length limited and require a larger opening for installation. In this situation I would go with at least a 2D heli-coil, 3D if you can find it.
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went to ace on beamer and it turns out they have the same bolts but longer and chrome plated. The ones that came with the yellow terra rockers are way too short. Not only that i broke one of the yellow terra bolts and found out they are not 12.9 grade like they say. Drilled it out in less than a minute. Like butter. The ones at ace are what should have come with the kit. correct me if im wrong but metric 12.9 grade are about the same rating as standard grade 8.
Last edited by youguessit; Nov 28, 2009 at 11:56 AM.
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Different hole... i let my "special brother" torque it down... The only thing i let him do he screws up by overtorqing. Not sayin it wasnt overtorqued... just pointing out its not a 12.9 bolt like is stamped on it.Just to give you an idea of how soft the bolt was... i had it out with an old drill bit in less than a minute. The steel bolt broke before the aluminum head stripped out. Like i said before i would go with the longer bolts... I didnt even have to use the shims that came with the yella tera kit and there are plenty of threads still not being used in the head... only reason i can come up with is it is because i have tfs heads or they just dont come the appropriate length.
Different hole... i let my "special brother" torque it down... The only thing i let him do he screws up by overtorqing. Not sayin it wasnt overtorqued... just pointing out its not a 12.9 bolt like is stamped on it.Just to give you an idea of how soft the bolt was... i had it out with an old drill bit in less than a minute. The steel bolt broke before the aluminum head stripped out. Like i said before i would go with the longer bolts... I didnt even have to use the shims that came with the yella tera kit and there are plenty of threads still not being used in the head... only reason i can come up with is it is because i have tfs heads or they just dont come the appropriate length.
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Joined: Sep 2006
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sounds good i think im squared away here... just waitin on the tune on monday... my buddy will also be getting his car tuned for head cam. So it will be exciting for both of us.Thanks for all your imput. Ill give you some numbers then.
