Competition oringed 12-valve, take 3 (help?)

[bluthndr]

Alright. Blew my second o-ringed HG last night. First one was my fault for not retorqueing it right, but this last time it was fine for almost 3 months including spirited off-roading and dyno time. Then suddenly last night the heater quit, and when I checked it out it was low on coolant and started bubbling out the overflow when I refilled it. To the best of my knowledge it never boiled over either.



It's got ARP studs torqued to 125ft lbs (and retorqued hot at 5 miles, then again at about 500 miles), grooves cut and resurfaced by a major midwest performance diesel shop, and has never seen over 45psi and 1300* EGT since put back together.



I drained the coolant this morning and will try to retorque it just to see if there's any slack when I get home.



I know there are guys running double my power and boost levels that seem to keep them together, so what gives? I'd rather not do this a 4th time... Any ideas?

 

[JGheen]

and retorqued hot at 5 miles, then again at about 500 miles),

I'd have to say that was your problem right there. I would never re-torque the studs while the engine is hot and everything is expanded. Your torque to 125ft. lbs is correct but I would not re-torque hot. Wait till the engine is at least 100*F or below then your re-torques will be more accurate and you wont over-stretch the studs or decrease their clamping capability.



Joe

 

[Graphic man]

I agree let it cool to about 100 and then do the re-torque, make sure you use TONS of ARP lube, do one at a time back them off 1/2 turn and torque to 125 ft. lb. and see if you can get your TQ. wrench calibrated, any Mac. or snap-on truck should be able to do it for you.



Scott

 

[bluthndr]

I did it just barely warm the first time (when it lasted a week). The guys that oringed the head said to do it hot, and that is the way they do it, and they never have any come back? To their credit, it did last longer this time...



It was done in 3 stages with a brand new Snap-on digital torque wrench. (I AM the Snap-On truck)



Any other ideas? I guess I will know if that is the problem when I try to torque it tonight...

 

[jwilliams3]

Dude, I feel for you.

My old 99 had an O ringed head and was great for about 20k miles then it let go.

Of course I didnt have studs at the time...



Several retorques and headgaskets later... It still leaked. Bothered me so much I sold the truck.



I wont ever O ring a head again.

 

[bluthndr]

At least there's someone else who's had the same thing happen...



The whole reason I oringed it was to fix it permanently. Maybe I need to check the torque on the studs regularly?

 

[jeff2]

I would be happy to help GDP 1866 898 8585

 

[bluthndr]

At least there's someone else who's had the same thing happen...



The whole reason I oringed it was to fix it permanently. Maybe I need to check the torque on the studs regularly?

Just checked the torque - nothing moves even with the wrench set to 130 ft lbs... Time to go shopping #@$%!

 

[JGheen]

You should not need to check the torque regularly unless your drag racing every weekend or really hammering on it.

Take a scribe and mark a line on the nut on the stud and at the base of the washer on the head surface. Now you have a reference line. Break each nut loose about 1/2 a turn and re-torque to 125 ft. lbs. Do this in a line sequence..... so, start at the front stud on the driver side of the engine and work your way to the back of that line one stud at a time, breaking loose and re-torquing. When you get to the back of that first line of studs, move to the next line and work your way from front to back and so on. Make a mark on the studs that are most easily visible to you and if the line on the nut goes past the line on the head surface then you will need another re-torque after a good say 10-15 more heat cycles. If the lines on the nut and head surface line up after your re-torque, you should be good to go. It took me about 4 re-torques and about 2 months/40-50 heat cycles give or take a few for my lines to get within about 1/16" of each other. I was also running no higher boost levels then about 30lbs. I took it no higher than 20lbs of boost during the first few heat cycles and first 2 re-torques. Of course for your initial torque down of the head you will be doing the factory sequence and then the line method for the re-torques... ... COLD.

This has worked for me and I am still running strong for about a year now. I may do a re-torque in the near future just for giggles as it can't hurt to just check them.



Good luck, Joe