JD730

My 2000 started leaking oil out of the head gasket, #1 rocker arm feed. Pulled it apart and sure enough the gasket was push into the passage made by the gasket. Why, still not sure, no signs of a blown gasket, no carbon tracing.

Gasket was a .020" over thickness modified 12 valve gasket, head is o-ringed with studs.

Cold weather starts are terrible, it will not start without the grids and if its in the teens it will start missing on one cylinder and will clear out once the high idle kicks in. Should I drop back down to the stock thickness and modify a normal 12 valve gasket? How much compression did I drop by going to the thicker head gasket? I only run a set of M1.6's and about 360hp with no plans for more.

My next action item is to clean the deck and the head and check for flatness.

Thanks,
Mike

BC847

Mike, how much o-ring protrusion ya got?

JD730

Didn't check that yet, I didn't o-ring this head. If I had to guess i'd say its around .010". Thats one of the many things to check when I get home today.
And this whole oil leak is new, maybe a month old. The head has been on for about 50,000 miles and was retorqued 3 times after a heat cycle letting it cool a couple of hours before retorque.

Mike Holmen

Why your reason for using orings? If your not running high boost, its a waste of money and a pain in the butt. I had a oil passage on #6 failure on me last year. The head wasn't tight enough against the block. You using ARP's studs right? I cranked mine up to 135ft*lbs and used the ARP lube on the treads. How many heat cycles have you done and re-torques? There more to installing orings vs a standard head. You have to get the orings to bite into the gasket and squeeze down hard. After each re-torque you should relash the valves as well. I had four gasket fail last year, three was from a bad torque wrench, one was from a lack of time and I rushed thru the install.

JD730

Planned on doing more at the time, but plans change.

I know I did 3 retorques with at least one heat cycle maybe 2 heat cycles between them.

Mike Holmen

You using stock bolts or ARP's? Why did you go with a thicker gasket? You shave metal off the head? What torque value did you use?

JD730

ARP's, went with a thicker gasket with plans to go further, plans changed.
I used 125 ft-lbs.

JD730

Well, it looks like compression got past on #1 cylinder.
O-rings have .008"-.009" protrusion.
Head and deck are flat.

Guess I'll go punch bigger holes in a 12 valve gasket. Any reason I can't use a stock 24 valve gasket? I know the 12 valve gaskets look like they have better sealing traces in them.

Mike Holmen

I used a stock gasket in my truck. Protrusion of 8 to 9 thou is lots. Mines around 5 thou area. I would also crank up the torque higher than 125 to 135 ft*lbs.

Jetpilot

.010 is normal for O-rings...... I like .010-.012 for street trucks. Clamping the studs to a higher torque value does no good only weakens the stud!. Use the ARP recommended torque of 125#, and use lots of the ARP moly lube. I like the 12v gasket in the .020 over but you will lower the compression slightly (a little less than 1 point). You can go with the standard 12V gasket and get the compression back if you want, the number for it is 3283335 (if I remember correctly).

JD730

I already have one .020 over that is modified already. Mine as well just throw that one on it.