Fixxxer22

well.... ive had tons of help with my cam issues here in these forums of offshoreonly. and again i have another question. what is the torque spec of the head bolts on thes marine applications. i have a factory gen v 502 and the heads that came with it. anyways some food for thought im a diesel tech at a ford dealer and when we replace head gaskets on the 6.0 powerstroke they are torque to yeild. 65ft lbs then 85 ft lbs then 90 then 90 then 90. when your done you either want a cigarette or a nap. anyways... just needed that spec. mabye is ther a online shop manual i could consult?

alecsammy

I believe its 92lbs. for a 502 and 85 for the 454. I had bought a set of dart heads and there bolts at 78lbs. the threads ripped out of great bolts I purchased from dart. The bolts had manleys name on them, I called them but could not get any info on them because someone else makes them. So the torque all depends on the tensile strenght of the bolt a 7/16 -14 bolt at 170k tensile strenght should have 73 foot pounds a 190k bolt should be 82 ft lbs and a220k bolt should be torqued at 91 ft.lbs all with 30 weight motor oil as lube this info can be found on ARP's web site. I ended up useing my old pioneer bolts and torqued them to 75 ft lbs. My engine builder said that would be fine with a low compression engine like my which is 9.1 will see . hope this helps

Fixxxer22

yup yup im low compression. and to my knowledge cast to cast bolts can be re-used. but i dont know any of this chevy crap. gimme a powerstroke anyday. then i might actually know something. mabye i should put a powerstroke in my boat?

ezstriper

75 long bolts, 65 short..Rob

Griff

It depends on which head bolts and lube being used on the head bolts.
There is a bolt torque order as well.

Fixxxer22

454 gen 5 says 80 ft-lbs. the the 454 mark 4 says 80 ft-lbs but in 20lb increments from 40. the pattern wont be a problem most head patterns want you to start in the middle and work your way outward. usually.... but i want to get the heads back on it tommorow at work but im still drawing a blank for the 502 torque spec

Griff

You always have to torque in increments. If you don't want them to leak, then use the correct bolt torque order. I hope you are using Marine head gaskets. The cheap auto ones won't last.

BTW, you need to use thread sealant on the head bolts since some bolts go into water jackets. You also should use new head bolts if those are 15 years old.

wbwjr44

I have a Gen 5 BBC im putting a set of Aluminum heads on it .Which Head gaskets do I need to stop them from leaking Water? from