L67 gaskets right? They should be fine at 14psi without detonation. Even my L36 gaskets with stock head bolts held on a couple "oops" 16 psi pullsIt has been running great, little to no knock even when it was 90+ degrees out. I'm kinda confused why it happened. Is there a certain power level where headgaskets typically become an issue? Im running right about 14lbs of boost.
So I put another set on, took it to the track (this time turbo'd at about 14lbs of boost) and all of the coolant ended up in the oil. VERY strangely though, because the car ran perfectly fine. We drained the oil and flushed everything out with 2 more oil changes, car ran fine, water system pressurized like it should and the coolant/oil didn't mix. I didn't trust it though because I ran a full 1/4mile with the coolant mixed with the oil as I didn't realize it happened yet. So we put in an L32 with MLS and never looked back.How’d you remedy that problem?
That's exactly how mine broke in the exact same place. I was able to drive it all the way home from where I was but about 3/4 of the way there pff pff pff pff turned into POP POP POP POP as the rest of the gasket pushed and it was straight leaking combustion.I went and checked the oil just now, clean, no coolant. So that's a plus. It must be blown where there's no water jackets, no coolant leaking externally, not burning coolant, and no coolant in the oil. Seams to be only leaking from combustion chamber pressure. Kinda weird, but what ever. Ill be taking the head off tonite.
I was actually scanning when this happened, it picked up about .8 degrees KR during that pull. But I did notice injector duty cycle was at 95% and the afr went alittle lean. Maybe time for 80lb injectors. I’ve been scanning for over a month, injector duty cycle never went over 85% before. Maybe this cooler air we are having made the difference.Mls is usually weaker than stock.
Gm ac delco usually are the best. Victor reinz made them.
Make sure they are for supercharged engines because they have a fire ring to make them more durable.
Head gaskets always blow from detonation. Any little bit of detonation you see results in much higher cylinder pressure than you'll get from making a while bunch of power. I forget the math....it might be exponential...but I think a good rule of thumb is 3x the cylinder pressure from detonation that you would normally see without detonation.
Man, i cant remember the sequence or torque. I used arp specs and gm sequence i believe. But yeah, it blew out into the lifter valley also. And i dont remember any additional tightening of the middle 4 studs.you popped inside and outside.... did the tq sequence you use involve a final step of the center 4 bolts getting an additional bit of a grunt?
iirc it was the earlier sequence that they did the 3rd step of additional tightening on the 4 center ones, then they discontinued it since it takes too long.
on the arp's i go 88- 90 and the center 4 go to 94
37ftlb and 120* isnt enough unless yer stock