Proper torque value and procedure for APR's?

Micahdogg

Registered User
Does anyone know? I read that Ken torque's his up to 95ft-lbs. Surely you don't go straight to 95, but you step em up like 30-60-95? What does ARP recommend for final torque?

Thanks.

Micah
 
I would not crank up an ARP head bolt/stud up to 95 ft/lbs. That seems very high. That's about as high as my 351W and that has 1/2 inch head bolts which can tolerate way more load than our puny 11MM head bolts.
 
I'm working from memory here but I think that the ARP recommended value is 80ft/lbs with molley lube. Lots of people have been over torqueing by 10% to about 90ft/lbs.....95ft/lbs is almost 20% over torque which seems like alot but I don't really know.
 
My head studs

When i installed my head studs i went by the recommended setting of 80the according to the paperwork in the stud kit. I did gradually get it there though, the first setting was 26, then 58, then 80. Also an fyi if you are using stock exhaust manifolds you will need to modify them to get them to line up. Otherwise the head studs prevent them from dropping in.
 
You need to go in large enough incriments in order to break the friction. going 20-30-40 for example is not large enough of a gap, so regardless of what steps are given determine the steps by the amount of room you have, on engine stand or in car. If you have to take two bites on one and only one bite on another, youve made a boo boo.
 
I went with 30-60-90..........


11mm 170,000/180,000 72ft/lbs torque ARP lube
11mm 190,000/200,000 82ft/lbs torque ARP lube
11mm 220,000 92ft/lbs torque ARP lube

ARP 233-4303 are 190,000
 
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Actually it was the last engine I ran in the car and did the heads on it. TQed to 95 in stages like everyone else. The engine I am running now was assembled by David Dalke so I cant comment on its TQ numbers on the studs. I never had any problems with the previous engine and I ran Fel Pro gaskets on it and MLS on the existing engine.

Ken
 
Thanks guys. I'm leaning toward MLS gaskets not being awesome, and 82 ft-lbs not being enough torque on the heads. I like the crappy composite ones that can crush into the imperfections better. And I will probably put those to 95ft-lbs.

I might try some copper spray instead of rtv this time though.
 
I would not crank up an ARP head bolt/stud up to 95 ft/lbs. That seems very high. That's about as high as my 351W and that has 1/2 inch head bolts which can tolerate way more load than our puny 11MM head bolts.

Out of curiosity, why would your 351W need more torque on the head than a Super Coupe with 17-20 psi of boost?
 
I did the 30-60-90 also, using MLS with copper spray on the block side since I have stock block that has not been machined to the proper RA surface finish. If you go with the composites I'd copper spray both sides of the gasket.
 
I think i will spray both sides. I'm going 95 though because my motor will probably make 5 more HP than yours so I'll want that extra 5ft-lbs of holding force!
 
Great question. I think it comes down to clamping force and the size of the hardware. I know that a 351W utilizes 1/2" head bolts which are much larger than our 11mm head bolts. I also know that most specs for the 351W call out for 95-105 ft/lbs for the cylinder head bolts. The 302 usues 7/16" inch head bolts which are more close in size to our 11mm bolts and the 302 requires about 70 ft/lbs of torque. The 351W is inherently stronger than the 302 or our 3.8 engine. If our engines used larger diameter hardware for the cylinder head bolts we would certainly be able to ratchet up the torque thus increasing the clamping force and I would imagine that would result in much less head gasket failure. That however would bring upon its own set of issues. I look at a head gasket the same way as a fuse. If we strengthen up our head gaskets, head bolts, etc. and lean out or run too much timing, etc, then something is going to give. For me personally I would much rather lose a head gasket than a piston or connecting rod. This is why I do not use mls head gaskets. If there is an issue I want the head gasket to pop.
 
I think i will spray both sides. I'm going 95 though because my motor will probably make 5 more HP than yours so I'll want that extra 5ft-lbs of holding force!

I think you're crazy if you use composite gaskets. And you should use the torque spec ARP gives for their hardware.
 
I think you're crazy if you use composite gaskets. And you should use the torque spec ARP gives for their hardware.

What's wrong with a composite gasket? You don't pop head gaskets because of gasket failure. You pop head gaskets if you overheat, lean out, mis-detonate, etc. I like having the head gasket as the weakest link. It's simple. If you run enough fuel, your ignition timing is correct, and don't run hot you won't blow head gaskets. I have seen the aftermath in way too many engines with mls gaskets that ran lean or had detonation issues. It isn't pretty and I would much rather replace a head gasket and let my engine live to race another day then shoot a rod or burn a piston. I know many people here will disagree and I have used mls in the past but i won't use them any longer. I know many folks on here will disagree but I like looking at head gaskets as fuses. If the head gasket is the weakest link then I am fine with that.
 
What's wrong with a composite gasket? You don't pop head gaskets because of gasket failure. You pop head gaskets if you overheat, lean out, mis-detonate, etc. I like having the head gasket as the weakest link. It's simple. If you run enough fuel, your ignition timing is correct, and don't run hot you won't blow head gaskets. I have seen the aftermath in way too many engines with mls gaskets that ran lean or had detonation issues. It isn't pretty and I would much rather replace a head gasket and let my engine live to race another day then shoot a rod or burn a piston. I know many people here will disagree and I have used mls in the past but i won't use them any longer. I know many folks on here will disagree but I like looking at head gaskets as fuses. If the head gasket is the weakest link then I am fine with that.

I don't think anyone has really ever blown a composite gasket on an SC. More like they just crap out over time. Fire ring pulls away after a while. Yet it is a long while before they tend to give up. You can blow a MLS too.

And I think we have come a long way with tuning especially with the QH. Better pistons, rods and what not. Whens the last time someone has burned piston? Smitty at the shootout like 3 years ago?

Anyway blow a gasket suck some water in bend some rods get it in the oil and you need a rebuild anyway. Shoot even worse spit coolant on the track run it over and wreck.
 
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