I know that I hear people say all the time that you have to replace the head bolts because they stretch, they're TTY, etc...

But I want to know what will happen with just a stock LS1 if the head bolts were to be reused?

Will the heads lift?
Will the bolts break (all at once or one by one)?
Will the heads flex and crack?
Will they not seal properly and result in a head gasket leak?

We need a myth-busters on this one.

I have never heard of any problems with people re-using head bolts in a stock application or any other application for that matter. I bought a bunch of LS1 parts from a guy who builds LS1 engines. He said that although he doesn't personally re-use bolt heads, he knows a lot of guys that do and he hasn't heard of any problems.

Somebody on here has had to of reused them...share you experiences with us.

I have yet to run an engine with re-used head bolts. I have installed used head bolts, only to take them back off and replace them with new ones. The used bolts seemed to feel just fine as I torqued them down to 65 ft lbs. When removing them, they felt tight and solid. I should have just left them and seen what happened.

Please don't just say that they have to be replaced because GM says..., or because they stretch...give something concrete...

 

yeah I'd like to know aswell..........

 

Its possible when driving aggressivly that you could lift a head and cause the head gasket to fail, which could lead to you hydrolocking your engine due to coolant getting into the cylinders. Which if that happenes you could probably guess what you would need to do after that. Personally I would just replace them. On one occasion I did reuse head bolts but that was when i was building the motor for my 1975 monte carlo, but that was before these torque to yield bolts were invented. Im sure alot of other people will chime in, but that scenario is prolly not the only one that could happen fwiw

 

I think the greatest risk comes from re-installing them and having them break while torquing them down. I'd hate to have to helicoil a block!

Next I'd say uneven torquing of the heads may result in the head gaskets leaking, possibly causing hydro lock as described above.

 

Worst that could happen, They back out and warp your heads & block. Heads don't seal, car overheats, blows motor.

 

please dont reuse the bolts. a lot of people that did reuse them, they usually dont get problems but why be cheap especially with a nice engine. they do stretch which is the main problem and even with the right torque, these will always be looser and wibrate more causing more stress on the head. if your gonna takje apart the head, dont do it cheap. do it right and get new bolts.

and if u do reuse em dont come crying back sayin your engines messed up cause your headbolt broke

 

Basically its like playin russian roulett with your motor. Not really a wise choice when you can get a new complete set of GM bolts from SDPC for $35.

Only time its ok to reuse them is if you are running ARP studs or bolts.

 

The clamping force developed by the TTY is even and specific as determined by the material properties of the bolt. With MLS gaskets and aluminum parts that have a lot of growth and movement during use and heat cycles, you are playing with the final clamping loads and the ability to maintain the clamping loads over the heat/movement cycles when you re-install a bolt that has already been used since the yield point in the material has now been shifted due to the prior yielding (after yield, there are pre-stresses locked into the bolt). I would think head gasket leaks would be the first issue you would run into since the clamping loads with the re-used bolts will be incorrect and undetermined. Just because they look still look like bolts when removed, doesn't mean they are the same as when they went in.

 

I used the same ones and have put about 5k miles on it since the head swap, also GM does not say that you have to replace them when removing a cylinder head

 

Just don't do it!!

Or, do it and get back with us on that..

 

stock bolts are cheap for new ones, I say dont risk it just replace them.

 

You do know these are TTY bolts right?? I don't give a **** what GM says, you never reuse TTY bolts b/c they are already stretched. They will not retain their original clamping force. It's way to big a risk to chance when they are dirt cheap to replace.

 

i reused mine....and i spray my car alllllll the time. Even running a tad bit more compression (milled .030) no problems

 

I say go ahead and do it and report back

 

Good luck with that....

 

Just because a few idiots reused their bolts adn SO FAR have not had problems, that isn't a gaurentee you will not have problems.

YES. GM does suggest replacing the head bolts. When I bought some head gaskets for a freinds TA the parts guy suggested it because it was a note in the computer.

If you want to be cheap, don't ask our permission. In a group this big there are ALWAYS people that think the same way or have done what you are contemplating. Just please don't post back a year from now asking for advise because the head gasket blew again or the heads are warped.

Re'

 

In GMSI (Service information) application it specifically states "USE NEW BOLTS" Not sure where you're getting your info from.

 

Those that re-used the bolts don't have a lot of miles on the car. Don't forget, GM is in business to satisfy customers. Having a head gasket leak, and potentially a hydro-lock, will not endear too many customers. Will the old bolts clamp it down, yes they will. Will the motor have future issues as a result, just a matter of time.

 

what mileage bracket r we talkin for low miles? when i install my headers i planned on pullin heads to make it easy =X im at about 4x,000 miles

 

LOL, thats not gonna make it any easier. Thats hell of a lot more work. Just jack the car up at least high enough to fit a stock wheel laid down under your front wheels & you'll have enough room to slide them in from the bottom.

I have never heard of anyone removing the heads to install LT's.