head bolt sizes

[slow6]

I was wondering if anyone knows which bolt holes go to which bolts, in terms of length (there are shorts and longs).

I was also wondering why the Haynes says to tighten them down to 37ft/lbs, then rotate an extra 120* degrees? why doesnt it just say "tighten down to 80ft/lbs (in 3 steps of course)?

I heard that Chilton is better...

This shiznitt is tough, this HOTT weather is killa! Much easier to do engine work with the engine out of the car!

[98Camaro3.8]

Re: head bolt sizes

Long ones go in the upper holes (inside the head).
Short ones go in the lower holes (oustide the head).

[slow6]

Re: head bolt sizes

thats what I thought! I figured it out, already got them both on

dont answer that other question about torquing, i know its a stupid question.


Is it bad to overtorque the bolts? I tried to overtorque them a little

[AZ3.8Camaro]

Re: head bolt sizes

They are torque to yield, like the rocker bolts.
Overtightening them could be bad, because you are already torquing them down pretty tight.

They only have you torque them to a small value and then the extra degrees because 80 ft lbs is different and dramatically affected by debris in the holes, bad threads, threads sealants, bad torque wrenches, etc. But 120* is 120* no matter what.

[slow6]

Re: head bolt sizes

torque to yield is:
give more torque than traditional bolts
newer than traditional bolts
are easier to break if overtorqued by 25% extra
you have to replace them with new ones

can you give any other explanation of the torque to yield bolts?
thanks

[98Camaro3.8]

Re: head bolt sizes

Google "torque to yield" and you'll get tons of info.

http://www.robbos.com.au/myweb/Tech_Bolts.htm

[slow6]

Re: head bolt sizes

HEH, i also reused the rocker bolts :slap:

[AZ3.8Camaro]

Re: head bolt sizes

I am not trying to be mean at all, but you really should be a LOT more careful with your engine.
Head gaskets, bolts..... You might get lucky, you might not. Its a crap shoot.