DavidPHumes

iTrader: (1)

Don't know what happened really, LS9 gaskets on an L33. TC76 only running 7# on a conservative E85 tune. Passenger side head.

Everything else looks good so I'm just going to put new gaskets on (doing the driver's side just because) and see what happens.

Stopped driving it one day last week and heard water boiling. Temps in both HP Tuners (driver's side head) and analog gauge on passenger side head never went above 220 but they were higher than normal. Everything was good (180* solid) prior.

SPRAYED 01

iTrader: (22)

Weird, hate to say it but it has to be some kind of installer error. Maybe not clean in that area? Not torqued right?

knuts82

Possible warped head..

koolrayz

iTrader: (26)

You lifted the head, detonation without a doubt. Colder plug? less timing? more fuel? something is wrong

SPRAYED 01

iTrader: (22)

With 7psi and e85 you would have had to made a major tuning mistake. What was timing?

DavidPHumes

iTrader: (1)

I'll check on timing. I'm running a base tune from a very reputable FI tuner. I do know that timing was conservative.

Plugs are BR7EFs gapped to .020. AFRs were right in the acceptable range. Heads were decked prior to installation.

I honestly am thinking improper install on the heads (meaning they could have lifted but probably not because of too aggressive of timing). I did follow ARPs instructions to a t but having never done it, there's definitely a chance I made a mistake.

I'm just guessing here obviously, I'll find out today after I put it together.

3pedals

iTrader: (3)

sub'd to hear what timing and A/F ratio in the tune

I8UR4RD

iTrader: (16)

.020 seems a little tight. a base tune on some boosted car (mine is one) is just enough of a tune to get the thing started. and moving down the road. slap a new set on it and get it some dyno chassis time and you may just find out where things went wrong. id check that cylinder head too to make sure its not warped.

3pedals

iTrader: (3)

in my opinion there is nothing wrong with running the plug gap on the tighter side. it certainly is not at all relevant to the head gasket failure

koolrayz

iTrader: (26)

+1 on the plugs.
You think it was an instalation error but it is a strange coinsidence that were it failed is a very common detonation failure area. was there any fluid pushed into the overflow before you had the failure? Anything weird about the way the level in the radiator stayed? No exterior coolant leaks?

I8UR4RD

iTrader: (16)

I was just pointing that out not implying it was a direct cause. I know for a fact that a lot of people are running between 0.028-0.035 on the 5.3 motors. If it hasn't been blowing the spark out then great. Better tootight than too loose.

The head gasket failure reasons have all already been listed. He's tuning himself (major props) and as mentioned running on a base tune, so looking over some logs may be beneficial.