Blown headgasket?

[bentley429]

Car is stock 302 h/c/i iron heads with a single turbo. It is dialed in tune wise and has never had any problems before. Went to the track two weeks ago made a pass everything went fine no issues at all car ran well. Let the car sit for awhile then in the staging lanes and I look down and the temp gauge is almost pegged, it was showing 220ish. Car was running for about 2 minutes I figured the sending unit shit the bed as it did the same thing once before and that was the issue. So I proceeded to make another pass, car seemed to slow down quite a bit and at the end of the track all I could smell was antifreeze and white smoke coming from the exhaust. So I pull over on the return lane shut the car off and pop the hood. Coolant spewing from the overflow all over the place. Let it cool off and fire it up and limped it to the trailer. Bring it home, got it off the trailer and started it to put it in the garage, it ran for about 2 minutes and smoked out my cul-de-sac, needless to say its smoking real bad. So at this point clearly I am thinking it blew a headgasket, just finished taking it apart. Intake doesnt look to have been leaking, there is no milkshake in the lifter valley, so I continued to the heads. Take the heads off and the gaskets look to be fine also but 1-4 and 6 and 8 all have a little milkshake in them. I did not look to hard for cracks yet so I will have to do that tomorrow. But my question what could the actual problem be? Could it of lifted the heads and the headstuds are just lapped out so it doesnt have a good seal anymore? Thinking I should atleast have the heads checked out incase they were warped at all. Atleast its the end of the season  

[stangman9897]

How much power are you making on the stock block.? 

[bentley429]

Around 460 through a TH400 might be a hair more. I suppose the block could be cracked, nothing was staring me in the face though.

[bentley429]

Block is fine. Thinking the heads were lifting causing the HG's to go. I didn't see it last night but the upper passages on the HG on #2 and #3 were blown out and the upper passage on #8 was also. I've been reusing the ARP headstuds that were on the car when I bought it. This is the 4th time the heads have been off and I really don't know how many times before. Is it possible the studs are no good? I was under the impression they are reusable. This is all at 15 psi which its seen plently of times on the street and never overheated but did get warm a few times(210ish). Might have the heads checked out to make sure they didn't warp.

[Disney]

I'd mill the heads to make sure they are flat and put it back together with new head studs and some 9333PT-1's

[bentley429]

Thats what was in it for gaskets, used to have 1011-2's before this set and never had a problem with them so I might go back to those.

[ash]

check the heads are flat..
the block is flat
you got enough fuel in the motor to not be lean ???  through out the whole run ??
boost does not = power....
airflow = power

i did find, oem stock heads , flexed and allowed the head gasket to move and compression gas to enter the cooling system.... arp studs and and amount of sprays and shit on the head gasket will not hold...
my sbc oem deal ,010 4 bolt, and 882 chev cast heads ,  went 7.2 @ 191 in a chassie drag car...... endless problems of things moving.

tune it just a bit rich, and should be safer.

[bentley429]

11.0 whole way down the track. Tune is spot on. Its world iron heads also not e7s. I'll order up some gaskets and studs this weekend and have the heads checked out this week. Car has about 8.4:1 compression at the moment with the huge chambers on the heads. I was thinking about having them milled down .030 to get me closer to 9:1 while they are off. Something that minor shouldn't effect my intake sealing correct? Has a lot of trouble hitting the convertor when its warm out so I hope the compression being raised a hair will help matters.

[ash]

11.0 whole way down the track. Tune is spot on. Its world iron heads also not e7s. I'll order up some gaskets and studs this weekend and have the heads checked out this week. Car has about 8.4:1 compression at the moment with the huge chambers on the heads. I was thinking about having them milled down .030 to get me closer to 9:1 while they are off. Something that minor shouldn't effect my intake sealing correct? Has a lot of trouble hitting the convertor when its warm out so I hope the compression being raised a hair will help matters.

ok,
tune up at richer tune, and see if it lives....
then u make the decision of leaner tune , more $$$ , and more maintainace
or
richer tune , less $$$$, more fun.......

head gasket moving, is from head flex, detination ( lean)
u just have to work out which one it is...
main caps, big end bearings, etc....the parts will talk to you and tell you whats going on inside

[jt351]

Wow blow head gaskets=strange isn't that an oxy moran.  I would think that boosting a hot engine like 220  would be more prone to detonation, correct afr does not mean anything, hotter temps requires less timing, if cylinder temps were off the chart no amount of timing retard could save it.  If your head studs take the torque without stretching they are fine.

[bentley429]

Wow blow head gaskets=strange isn't that an oxy moran.  I would think that boosting a hot engine like 220  would be more prone to detonation, correct afr does not mean anything, hotter temps requires less timing, if cylinder temps were off the chart no amount of timing retard could save it.  If your head studs take the torque without stretching they are fine.

At the time it was strange because I didn't notice the areas where they had blown out. The studs torqued down like normal when I put it back together a few months ago so I am guessing that would mean they were fine?