can i re-torque stock head bolts

[steves 86 supra]

you can reuse your head bolts as long as there not pitted

to retorque your head back each bolt off about a quarter of

a turn before you retension it, make sure you drop the coolant first

you will find an engine drain bung at the back of the block behind the

turbo,

i had a head gasket start to leak on my old NA motor about 1500 Ks

from home, retorqued it out the back of a servo & ended up putting

about another 50K on it while i built the turbo engine

ps dont use your tension wrench to back bolts off !

[cre]

Originally Posted by steves 86 supra

you can reuse your head bolts as long as there not pitted

Stretch is the primary concern (the TSRM has details on measuring the bolts to determine if they're healthy). Sure, if they're pitted, cracked, flaking, etc. you don't want to reuse them. You can't check either without pulling them and compromising the HG so it's a moot point in this discussion.

A re-torque usually won't last long if the HG has already started leaking... the longer it leaks the more the gasket material is subject to erosion. Catching it before it happens is key.

[supraluver4life]

i believe it hasnt began to leak yet because compression is still great. and by completely pulling the head bolts i risk comprimising the head gasket?? because i want to replace the eventually but if it isnt necessary then i wont

[pablo94sc]

If you have have the head off, replace the gaskets and do not re-use the head bolts. They are most likely torque-to-yield and will have stretched the first time installed and torqued to spec. Buy new ones and save yourself the pain of a blown HG when the bolts fail to properly keep the head mated to the block and lift under heavily acceleration (or boost if you have a turbo).

[cre]

They aren't TTY... I do agree with replacing 20+ year old bolts for peace of mind though.

[steves 86 supra]

Originally Posted by cre

They aren't TTY... I do agree with replacing 20+ year old bolts for peace of mind though.

try finding a nut and a piece of steel tube to fit an old head bolt
put the nut in the vice, the tube on the bolt and install finger tight
now take a stretch gauge and measure the length of the bolt, write
this down, torque to a given setting and measure,
keep repeating this process and see if u get even the slightest
difference, ive done this little experiment and found none
i used to use ARP head studs on all modified 7M's but now i see them
as a waste of money on all but the most highly strung engines
about the last 20 7M's ive built have had std head bolts only 2 ive
replaced them & none have had head problems
one of my engines gets cained at 22 psi every day with nothing more
than metal head gasket stock {second hand} bolts & proper head & block preperation

[cre]

Edited for clarity: I wasn't saying that stretch was likely (actually, I pointed out that the TSRM even provides the measurements to make sure they're fine)... I just didn't think pitting was any more likely. I should have simply said as much. I've only ever had 5 apart that far though. Now you've got me curious, how many pitted head bolts have you pulled from 7M's?