Well......it finally happened. Head gasket let go. Cool story though.

I knew i was really pushing the limits of stock compression / head gasket to 14 PSI on an AP2 @ 9krpm. So here is what happened.

For the last few weeks i have had a problem with my EGT's running too hot on the exhaust side of the motor and was shutting pulls down while tuneing with the AEM.....I found out that there was too much timing pulled out causing the burn to go mostly in the header heating things up and loosing power at the same time......so data logging the knock was quiet and i decided to start advanceing the timeing on the EMS......so from 6k up i was able to add 7 degrees untill slight knock was present. What do ya know.....EGT's temps fell down perfect....right where they should be and the car had never felt faster. So i think i'm good....right....WRONG!

Sunday night i am cursing home from the strip club @ 2 am on I-70...no one is on the road.....and i'm just dogging along 60-65mph half asleep.....coming up from behing me fast are HID lights and as the car passes me at about 80-85....he slams on the brakes hard to even up with me.....its a new black Pontiac GTO...the one with the vented hood....400 hp model(383 vette motor).....full shinny aftermarket cat-back exhast is present.....sounded loud as hell....i was still in 6th gear.....and didn't drop to 5th....he punches it and jumps out about 3-4 car lengths fast......my charger finally starts winding up and now hes not pulling on me.....i'm pulling him in....by the time i was door to door with the GTO i passed him so fast i couldn't even look over.....the faster we would go the more distance i was pulling...and then fuel cut hit in 6th....151 mph flashed and i looked back in the mirror and saw the HID's back about 5-6 car lengths....i let off as a slight turn came up.....the GTO caught back up....as we went onto the next big straight......he was 1 car length back as we got on it again from 120......i started pulling immediately as he had no chance at catching me and just as i was approaching fuel cut again.....oil shot all over my windshield....i could hardly see.....smoke coming out of my ventilated hood on the intake manifold side....i let off right away and he goes flying by......my S is mising bad.....and black smoke now fills the cabin up.....windows go down to get some air......its bad....I'm done.

Pulled off the next exit which was mine anyway as car sputters and dies....pop the hood.....oil everywhere from the middle of the head back to the firewall!!!!! the dip stick is even out...wipe things down alittle.....let it cool.....it fires back up and barely idles....more smoke everywhere.....i have 2 miles to limp home now as i did end up making it.....THANK GOD! It lost a quart of oil that fast.

So here is what i know so far....there is no mechanincl noise or seizure(no banging, poping, or tapping) it still held 85 psi oil pressure all the way home....and my EGT gague peaked at 850 degrees Cel which is perfect....so i know it didn't fry...peak boost was 14 PSI and peak rpm was 8900......so i am hoping right now its just a blown head gasket.....as i will now get a 2mm and install the ARP studs i already bought....i hope this is it...will find out soon....any suggestions from anyone who has had a similar problem.....and possible other problems i may be facing that i don't yet know about untill teardown?? THANKS

 

Great story and nice kill.

Hope the rebuild is painless.

 

ya, me too

since i am now pulling the head.....i am really considering going turbo

i can pick up a full custom made turbo kit with a new 60-1 cheap....i just need to get a 3mm HG and custom downpipe made.....once you get up around 400 whp this is really starting to get addicting....and i am maxed with my setup now.....so i got some debateing to do right now.

 

damn, how much power were you making at 14psi and stock compression?

 

I had only dynoed it at stock comptech boost(6psi) a while back when the initial install was done and it layed down 314HP Dynojet

since then i just installed smaller pulleys and used the AEM EMS and my gagues to tune on the street and it has worked fine.....i feel it should of been somewhere around 380-400 Dynojet HP

i was not going to go over 10 psi.....but thats when the charger really starts to come alive and starts feeling fast.....so i kept going to smaller pulleys and just watching the knock sensor tuneing.....my mistake was just trying to run too much timeing on the top end.....tuning becomes very tricky the more you max out pump gas on high compression......too little timeing and you will toast an exhaust valve...too much timeing and you will detonate and blow it like i just did.....thats why you want lower compression......11:1 is just not boost friendly

 

This is not good news for a few guys out there. Hey man, you said you were seeing EGT's of 850* Celsius. Correct me if I'm wrong (Sideways, JohnZ, Freakin 'Rican), but I think that might be high. I think I remember seeing Sideways mention that he doesn't like seeing anything above 800 even. Is it possible that you might have been running a bit too much timing or too little fuel?

 

Highly doubt you blew the head gasket, You probably melted some pistons due to detonation.

hence why there is oil, not coolant all over your engine bay.

what was your ignition timing at peak torque?

 

yup......just pulled the plugs

the 1st and 2nd plugs toward the front of the car the electrodes are gone....melted....they were iridium too.

the 3rd and 4th toward the firewall look like normal with a clean burn and a little black

god only knows what damage lies ahead for me the A/F i feel was ok.....it was too much timing

 

That's not sounding good.

Might have to put my smaller pulley on stock motor on hold for a bit.

 

Sorry to hear that bro. Lets just pray the head is still good, becasue from the way it sounds the bottom end is done.