Head Bolt Torque

[Trouble Maker]

What is the sequence and torque for a big block (502) with alumium heads???
Thanks..

[Trouble Maker]

TTT
Does anyone at least know the torque for a set of aluminum heads??

[EXTREMEBOATS]

Depending on the bolts, Stock or ARP???? A 7/16 head bolt torques to 70 foot pounds. I've had aftermarket bolts go more so ... As for how, start at the center and work out in a square pattern "center toward ends". I will torque in intervals, starting around 50 pounds first then follow back to 70. You just have to remember alum heads flex more as you tighten them down. Be safe though and chek with the head manufacture first. I've built a chit load of alum head engines this way and never had any problems. But im sure someone has a different theory on this. :( :notam: :rolleyes:
Mike

[Trouble Maker]

Thanks....

[SmokinLowriderSS]

My Big Block Chevy source book doesn't include the 502 as it is an older book, but it makes no distinction on torques for the MkIV blocks Aluminum or Iron headed.
Long bolts, 75 pounds
Short bolts, 65 pounds, all coated with silicone (they are in the water jacket)
Studs, long, 65 pounds
short, 55 pounds
Valley studs for aluminum heads, 50 to 55 pounds. (the only distinction)
Again, all siliconed

[SmokinLowriderSS]

Sequence is from the center bolts out, on both sides, the last bolts being the ones on the outer corners.
Center bolt first, center shortie by the exhaust next, then the pair to the rear, then the shortie near the exh fwd of center, then the next pair to the rear from Exh inward. Then the pair fwd, from exh inward, then both the outer exhaust shorties, then the aft inner bolt followed by the fwd inner one. Lastly the aft pair (inner first) followed by the fwd pair.
Hmmm Center, center exhaust, center aft, next to center aft exhaust, next one fwd exh, center aft then exh below, next exh fwd then center above, next aft exhaust, next fwd exh followed by fwd above, rear pair, inner first, lastly fwd pair exh first.
I don't know how to throw extra studs in but is still basically "center staggered to the ends". I'm having ZERO trouble with my recently rebuilt 454, iron heads here.

[Wicked Performance Boats]

Gen5or6 bolt torque is 80 lbs on all headbolts, alumium or steel. No sealant,only oil, they go into blind holes Budlight

[SmokinLowriderSS]

Cool. The older Mk IV blocks put all the bolts into the water jacket. :shift:

[Wicked Performance Boats]

That's the main problem. That's why I use studs. Budlight :idea:

[Trouble Maker]

Thanks for the info guys...much appreciated!!

[Panic Button]

ARP studs use different torque values depending on if you are using 30# or the ARP Lube.

[EXTREMEBOATS]

Blind holes or not, studs are the best. And yes ARP has there own way as I said. Hands down you cant go wrong with ARP... :rollside: Mike

[SmokinLowriderSS]

Hey!!! Someone found out how to copy the rigfht page in my book and POST IT!!!! :2purples: That is my usual refernce book. hahaha. My page 52 has a few more grease stains though. :crossx:

[Trouble Maker]

Dude, what book did you get that out of... I need one..
Thanks..

[Wicked Performance Boats]

ARP.com, I think. Budlight

[Trouble Maker]

Thanks again..

[Floored]

Both gen 5's in my garage, the headbolt holes go into the water jacket. 1992's mercruiser 7.4 and a chebbie pickup 454. using silicone to seal them.