N.Johnson

'll give you my 2 bit answer..... you blew the stock gasket and the heat warped your deck. It doesn't take much just a hot spot will spoil the flatness profile. The only way to get that puppy to seal is machine it flat again......Check the head with a good machinist straight edge and feeler gauge.

Snapoff

I run plain ARP studs.

Heat cycle the motor a few times.
24vchevy was telling me that he got a full 1/2 turn out of his studs just warming the engine once.....

It is not the power or boost that pushes the head gasket off.
What usually kills head gaskets (rods and bearings for that matter) is too much timing (peak pressure at or before top bead center). Extreme egt's usually go hand in hand with this sort of a setup.

Stack a Smarty and an Edge (or TST), throw in some bad settings, and you can eventually say goodbye to you headgasket...Seen that a few times....All this at less than 500hp.

Make a similar error with an 700-800hp motor and you had better prepare for a devastating failure.

Once a head is warped O rings are pretty much the only hope...Just don't mix a multi layer gasket with o rings.

12valve

Asked quiete a few people about what HG to use, and about 50% said to use a 2nd gen, others to use a MLS HG. since we had such bad luck with a 2nd gen HG, and didnt get another one, i went with the OEM MLS CR HG. had good luck so far, loaded SW2 in the smarty, set timing to 4 and set the wastegate lower and made a 80 mile trip, after that retorqued the Studs to 130 lb.

How should i use it now? when is it ready to load sw9 and a little shot of nitrous?

12valve

now the MLS HG let go too, shortly after installing dual cp3s which caused the truck to make about 10 psi more turbo boost... 60 psi total

What HG should we try now?
We are thinking about ordering the 12v Marine HG .20 over.

whats your opinions?

ratsun

Since your head is oringed a MLS wont work
You need to go with a modified marine but if the block or head isn't flat or the oring protrusion isn't true, nothing will last.
IMHO the quality of the machine work is paramount and no off the shelf parts will compensate.

bluechrome

Your not the only one to find the limits of the MLS gasket. There have actually been several including myself. I'm going with a 12valve marine gasket and o-ringing the head. This has worked on Tim barbers insane 100psi+ beast and several others. My truck has been studded for the last year but the hG couldn't handle the DP's and egts. Since I discovered that the hg has been blown out internally it has resealed itself under light boost. But, as soon as I hit the throttle boom coolant all over the place. When Placing the head back on make sure the head and block are within sped and not to distorted

DMS1707

No reason for o ringing stock gaskets are fine for cr.I run 10's at over 1000hp on the motor with stock gasket as long as you torque properly should be fine. I'm running the new 625 studs had some problem with standard one myself but they work just fine.. I'd have the head check with straight edge and have it resurfaced if needed and the deck of the block looked at also.

CrashCade

x2 on that. Check your head and deck on the block. If it has the least amount of warp to it I would have it decked and resurfaced. If it has a lot of warping to it, you can still have it machined and just run an oversize gasket to compensate. Something is not right if you keep blowing gaskets.

12valve

we wont pull the head before the marine gasket gets here, But if it should be warped, how would one go about the o-rings in the head when resurfacing is needed?

DMS1707 Whats wrong with the normal ARP studs? What do the New 625's do better? Im just trying to learn here, and figure out if i should go with the 625s or if its not needed!

BTW the orings have .007 to .008 protrusion

Jetpilot

I would have the head decked to ensure the head is flat with a very high quality RA finish, and allow for .010-.012 protrusion of the wire. Install new SS or inconel wire being very careful to not dent or scratch the wire. As for the 625 studs they are made from ARP 625+ material that allow for a higher clamp load..... The torque spec on these studs is 150#!

12valve

havent found a machine shop yet that can do a good oring Job close by, Member ronnyenns on here has had quiete a few issues with his fire ringed head that was done on a milling machine. We bought the used head already oringed.

The ARP torqued down to 150 makes sense!!

btw, PDW cant ship out the modified 12v marine gasket .20 over
till in 2 weeks. i need it ASAP! anyone else carry those?

94ttss

Go to your local Cummins dealer and get a 12 valve marine gasket. Give Tim Barber a pm for details.

12valve

ok Thx!
did so!

What do you do to keep your HG in place?

94ttss

I'm going to go the same route shortly, ARP 625's, o-rings, and a .010 over marine gasket. I know it's just a matter of time so I picked up an 05 head to get done. I'll swap it out in a day so no down time, and then sell my head to recoup some costs.