01Bird_of_Prey

Currently building a new setup - 408 stage 3 heads, sdce spring tension setup - makes 17 psi - having problems with the heads lifting on the driver side. I had the same problem when I was making 10 psi with stock mlg's, so I switched to cometics and still the same problem. I have arp studs torqued down to 75 foot pounds.

I'm starting to get aggravated -- could someone with a similar setup tell me how to keep the heads down???

HELP!!!!

cyphur

iTrader: (10)

Hmm....I'm very interested in this. I'm planning on the same setup, but mine are a little ways off

mr2guru

iTrader: (16)

Go with 7/16" headstuds? Either that or experiment with higher torque values on those headstuds you have....

obZidian

iTrader: (2)

maybe chris from ape could chime in?

Hes running nasty amount of boost on a f2 (i think) blower.....

1bad2k2ta

iTrader: (3)

Are the heads o-ringed?

Slowhawk

iTrader: (12)

Torque the heads to 85-90ft/lbs with the studs. I'm guessing the 17lbs will be from a F1 since a D1 wouldn't have a chance

Bryan Wilkinson

iTrader: (1)

You have a two fold problem. Your studs are not seated properly in the block and over torquing will cause block distortion and the heads will never hold.
Problem#2 is with blown applications the heads need to have a very thick deck, like the AFR's and some of the new castings coming out in a couple of weeks. Cometic can back me up on this.

01Bird_of_Prey

no not o-ringed I have a 04 block that all the stud are the same size
and are pro series.the funny thing is it leaks in the same spot driver side back
(#7)

01Bird_of_Prey

This is a brand new cast iron block. I put the studs in the 1st time as ARP instructed - all the way down hand tight. The 2nd time I lock-tighted them in by hand.

01Bird_of_Prey

It's a D1sc @ 56000-rpm@6500

NA$TY-TA

iTrader: (21)

crank is a 7.25", but what is the blower pulley in inches????? FMIC?????? Not the stock twins right....... I know Chris is running a set of custom ARP L-19 head studs...... i dont think he has any left and they were around $400-500 if i remember right.
Any pics ??
Kyle

Mike 01WS6

I dont know how the fast guys are keeping them on. But you might want to PM one of them. Harlan is keeping his heads on at 25+ PSI. Steve Turley and Mike Brown are keeping the heads on their car as well, its a 6.0L block, but I believe they are still using ported aluminum 6.0L heads.

LSs1Power

iTrader: (5)

Did u ever dyno your setup at 17psi? What is your cam specs? 17psi from 56000 D-1SC RPM is really nice.

MelloYellow

Were the ARP studs new?
1st time they need to stretch, also Cometic gaskets suck.

Now that ARP studs are stretched, if you go back to GM MLS at 75 ft/lbs I think you'll be ok.

If that fails, I'd check the head and block surfaces.

Rick@Synergy

iTrader: (5)

Even ARP will tell you that once you run the engine, go back and retorque the studs again because of heat and stretching. I havent seen a problem with running good amounts of boost. We are at 13-15 PSI on some cars and we use the GM MLS gaskets, no o-ring. Are you tuning the car yourself? Or do you have someone doing it for you? A problem that you could be having is the tuning. Improper tune will lift heads. Hope this helps.

Rick

y2khawk

iTrader: (5)

detonation

Especially since it's always number 7, 5 & 7 are the notorious ones for running lean first.

What fuel, compression, cam, A/F, advance?

standard ARP studs and GM gaskets will hold 17 psi without a problem.

MelloYellow

True, what is your fuel setup?

PurEvl

iTrader: (2)

Drop your timing some, getting to hot most likey. Like Harlan said

Bryan Wilkinson

iTrader: (1)

Im just telling you what causes the problems you are experiencing. If you are using a LS1 or LS6 casting and running over 14lbs of boost the bottom deck plate on the heads is not thick enough for the amount of boost you are running. Everyone else running that much boost, should be checking their head bolts on a regular basis. The heads are getting warped on the bottom of the heads. Don't believe me?, take your heads off and take a straight aluminum bar put something like 1200grit paper on the bar and run it across the bottom of your heads. You will see that it is no longer a straight surface. Once they are warped, the gasket is not going to sit still, and heads are going to lift.

Call Cometic, they will verify this for you
Call AFR they will also verify this for you
FYI

MIGHTYMOUSE

iTrader: (59)

i think block/head are not flat.. at least not anymore assuming you have gotten control of the tune with race gas