panic

every how long head bolts should be tighten? i have alu heads on a 406ci application, the engine builder recommended me to re-torque bolts after a few hundred miles after running in but i never did....

Bob Onit

What brand and model heads you use?
Maybe the website has specifications.

Jughead

I don't remember the source, one of the rebuild books though. I checked the torque again after a few hot/cold cycles. Maybe 100 miles. None of the bolts needed re-tightened.

panic

bob, heads are alu race afr 210 cnc machined

norvalwilhelm

Doesn't the head gasket decide if it needs retorquing or not?? On my head gasket it said to retorque after one heat cycle.
I never did because it requires the headers to be removed to get at some of the bolts plus I would have to pull the valve train.
Before pulling the heads this fall I did test some of the bolts with my torque wrench and one proved to be loose.

Bob Onit

HEAD BOLT TORQUE:
All Aluminum heads should be torqued to 65-70 ft/lbs. This should
be done in the proper General Motors sequence in 10 ft/lbs increments beginning at 40 ft/lbs. Moly lube should be applied between fasteners, washers and areas around head bolt to prevent galling and improper torque values. All high compression, supercharged, turbocharged & nitrous motors should receive a retorque after the first run-in and complete cool down.
________________________________________ _____

Panic,
Above are the instalation instructions
I found it in the FAQ on the website

Heres a link to the site so you can read it all.

http://www.airflowresearch.com/sbc.php

panic

thanks for the link, maybe you won't believe me but i'm frankly afraid to give this engine in the hands of any local garage here where i live at moment (spain) to do any job (included retorque heads)...the engine is quite a piece of jewel and assembled at top level, it has been runned in and tuned close to perfection, builder is 'american speed' the same that has tested the new afr 'eliminator' heads (as you can read in the afr web site).

the retorque after the first run in has been done at builder's place alright, i wanted to know if a second re-torque should be needed, after a few hundreds miles on the street...thanks/Giu

zwede

Panic: If I were you I wouldn't touch it. At the most it would require one re-torque. I don't see it needing a second one. Many head gaskets (the "composition" type) do not need a re-torque at all. Shim gaskets need one re-torque.

Bob Onit

According to the information I posted the answer was no

"All high compression, supercharged, turbocharged & nitrous motors should receive a retorque after the first run-in and complete cool down"

Since you have had the heads re-tourqued once I would say...Dont worry one bit
Your all good to go!