Engine/Transmission (1994 - 1998) what is safe boost for stock head and bolts

[LVJUNIOR]

What do you guys feel is a safe boost level for stock head bolts and gaskets at 16. 5 degrees of timing.

 

[Missouri Mule]

I've read where 50 psi is max for stock head gasket.

 

[LVJUNIOR]

Bad news for me. I was adjusting the waste gate and noticed antifreeze coming from the rear corner of the head. Looks like head studs and orings for me.

 

[CodySanders]

sounds like you found out the unsafe limit. sorry to hear about your bad luck. in my opinion and what i run is a max of 40 psi with stock head bolts and gasket. make sure to check the torque on them first as mine was off with about 88k on her

 

[LVJUNIOR]

That's the worst part. I have never had it over 35#. I saw the leak when I was adjusting the waste gate to 40#

 

[rsaderlund]

I popped mine this last weekend at Somoa Drag Strip. 42 psi on stock headbolts. Getting it studded and o-ringed at Ponci's. Two runs over 100 in the quarter took it's toll:-laf

 

[hsmith]

Have my gate set at 38 but seldom let it go past 30 psi. I tow a lot and need the dependability.

 

[telliott]

I have also heard 50, but i would be hesitant to push it that far. I have also heard that a lot of that depends on egt's. The hotter the egts, the less boost it takes to pop a head gasket. If you could keep your egts down, i think you would be more likely to be able to withstand the 50lbs some talk about.

 

[hsmith]

True, I also keep the egt's below 1250. Sometimes I let it get there but only for a very short time. Most of my towing is in the 1150* or less range.

 

[PRohr]

It's all about the EGT's and drive pressure... . but bolt torque and just the general health of the gasket and motor come into play as well. If you are running a stock turbo with bigger sticks you are doing nothing but pushing hot air and you'll have high drive pressures past 35psi and you are asking for a lot from a stock head gasket... with some miles. Put a bigger turbo on and drop the EGT's and drive pressure and that higher boost is easier on the engine and gasket.

 

[Hammer]

12v head is known for cracking back in between cylinders 5 and 6 and it will leak antifreeze there. Mine did the exact same thing along time ago and looked like the Grand Canyon between those two cylinders.



As for boost.....

45 psi is considered safe and anything above that could be issue. HOWEVER,I have seen some headgaskets leave with less than 45 and have seen some hold more than 50. The one on my truck was in good shape when we pulled the head back 2 years ago and it has seen 45psi regularly. That being said with boost levels at 45psi ,the crack showed the heads casting weakness instead..... Andy

 

[champspa]

28 to 32 psi is safe and dependable with good power .

 

[CumminsPower98]

My timing has been at 16 deg. for a long time and hundreds of thousands of miles, many of which were towing. I also run a stock turbo. My original gasket finally let go at about 38 psi when I had 247k on the truck. I was towing with wind in sub-zero temps. It got that high by accident. I had a compression to water jacket leak but was able to finish my trip of nearly 2k miles by keeping the boost under 20 psi without any problems.



Like others have said there are many factors that play a roll. From my reading and experience I would say keep it below 35 for dependability.



If you have an external coolant leak that doesn't mean you have a compression leak but of course still requires the head comes off.