This may sound like a silly post but I have to know. It has been three years since I changed my head gaskets and when I did them I torqued my head bolts to 55-56lb-ft. I know that 65lb-ft is the manufacturers spec but one of the head bolts was being reluctant to take a solid torque reading at 55lb-ft and I did not want to strip out the block. I will admit that I was using a beam style torque wrench but I have checked it against my "click" style torque wrench and it appears to be spot on. I did clean the block threads with a tap and I have since learned that this can remove thread material and risk stripped threads. I have wondered if the bolts were not to blame but this was only the second time they were used. I am worried that my block might be damaged but it's a new ZZ4 short block, is this possible so soon? I also hesitate to torque the head bolt really tight because these aluminum L98 ZZ4 heads have given me alot of crap in the past. The intake bolts will not go above 15lb-ft without stripping, the spark plugs will not go above 10lb-ft without feeling like they will strip out, and I hesitate to crank down on the head bolt because I fear that the aluminum is giving way underneath the bolt heads. I did state that I have had these bolts torqued to 55lb-ft for years and with many drag strip passes I have yet to experience a problem. I just feel like my engine is at high risk for a future problem. Any input would be greatly appreciated. I hope I am not alone in my frustration. I really care about the work I do but it seems like my engine fights me every step of the way. Are your experiences with head bolts on aluminum heads similar?

 

As long as you have hardened washers with the head bolts, you shouldn't have any problems... I assume you went incrementally to 65 ft/lbs??

 

The ZZ4 bolts do not have washers and I set all head bolts to 56lb-ft.

 

i doubt you have a problem and i'd wait untill i really had a problem, like a leak or head gasket failure before i tried to fix it.

 

Thanks ede! I feel the same way but it is nice to be validated by people who I feel are very knowledgeable. I really have a hard time finding anyone to speak with about the problems I encounter locally. That's what makes Thirdgen.org so great!

P.S. If the block did strip out would a Heli-Coil and head studs be the only option for a fix?

 

not really the only options but the quickest and cheapest would be a heli coil or other type of thread insert.

 

Any other opinions?

 

Personally, I feel that with modern head gaskets and a N/A gasoline motor, 55-60 is enough. You can cause far more trouble over-torquing them than leaving them a tweek on the low side.

OBTW, I greatly prefer a beam or dial type wrench over a clicker. Takes longer and requires at least 2 of the user's neurons to fire at the same time but is far more accurate in actual usage.

 

TTT

 

Up until last week I had aluminum L98 heads (upgraded to pro topline). The intake has been removed/installed at least five or six times since I've owned them and I've always torqued it to spec without any problems. I've gone through numerous sets of spark plugs while tuning the carb and have never had a plug hole strip out. I do recommend you use NEW head bolts every time you reinstall heads. The felpro ones I got are $25 for both heads and are designed to stretch when torqued so although they may not fail if reused, it's cheap insurance. GM isn't the brightest when it comes to some things but I'm sure they had a factor of safety when they set the torque specs for the head bolts so I wouldn't hesitate to go 65ft.lbs.