it says they reccomend retorqing after start up. is this something super critical or can one get by without doing it, thanks, jon

aLWAYS RE TORQUE ANYTHING ALUMINUM.

What about newer engines where after the bolt is torqued then they are stretched a 3/4 turn?

Many on the race section have said they did not retorque their head bolts after the eng was warm. I was surprised as how many do not do it and have said they had no problems at all. Course you have to unbolt the headers on the bigblock and I guess many did not want to do it. I did retorque the Eddy heads on my sons 400 and they were all good so I did not do it on my 440/493 with EZ heads and it has been running fine with no problems since 2011. Ron

I didn't bother will my 440 source heads but I used Cometic MLS gaskets so my thinking (perhaps incorrectly) is that gasket squish is less of a factor and therefore a retorque less critical.

better safe then sorry.. it's only an hour of time. Or at least check a few of the easily accessible ones?

MY first RB rebuild, 413 iron heads, FWIW, I didn't retorque the stock shim head gaskets.

They failed, so I go to pull iron heads off and replace them, retorqued them then.

What head gasket are you running and what does the head gasket maker say?

I have done many engines with aluminum heads and never retorqued them. No problems to date.

al. block and heads.3 refreshes.never a re torque and never a prob.

My Stealths have been on like 5 or 6 years now.I run 12.5 domes on the street.Used FelPro marine gaskets.Never retorqued them and no problems.Same when I do all ny heads.Rocky

Most new engines use aluminum heads. As far as I know not one of them needs retorquing.

Retorquing is a gasket thing. It's also a belt and suspenders method to eliminate one possibility of failure. I can't blame 440Source for saying to do it because it hurts nothing and assures the heads are properly fastened to the block.

Bolts that use the torque angle method are causing the bolt to yield during tightening. This assures that the bolt is loaded to its maximum capability. So I wouldn't think those bolts would need retorquing. If you did retorque, you'd put the bolt farther into yield and probably cause necking down past the allowable.

My Mercedes engine has torque-to-yield rod bolts. They allow reuse as long as the necked-down portion is greater than the allowable minimum.

R.

Newer engines with aluminum heads use torque to yield bolts. These are different than the usual factory or ARP bolts offered for our engines. I torque during assembly to seat and crush the gasket, loosen, and retorque. I don't wait for the heat cycle.

Always been curious, after the initial warm up retorque, is it recommended to re torque aluminum cylinder heads periodically? Like once every 30k miles?

If it was all dealers would have millions to retorque.Unless you run a full race car its not necessary.But if it makes you feel good do it.Rocky

I have never done it--almost always use Felpro 1009 never had an issue
Work at a shop that churns engines out the door--never retq or advise customers to do it
Now...I raced an LA small block for years--10 head bolts--we always ran clear hose on the evacs--when you saw vapor in the tube you better put a new gasket on before next race--we did retorque the small block race engines--did it help? who knows--with high compression and 4 bolts per hole it was simply a thing that had to be done but with big blocks no way I would waste the time---I will tell you this--if both the block and head are flat--you could almost run no gasket--but if surface prep is poor or ignored it seems to me to be the root of all head gasket issues