here is your big chance, because I am actually listening this time.

OK, here is my situation. my car is tuned properly to run 11.3 or so air/fuel ratio on pump gas. it runs 18 psi on a super 20G turbo, and I have "extensive" flow work. i also run ceramic coated je pistons, and stainless steel valves. well, my msd ignition went bad, and was causing my car to buck stutter under boost. this kept my car around 320 wheel hp at 18 psi.........not good. my timign was also retarded abotu 5 degrees, bringing my timing back down to abotu 18 degrees at wot. the motor never saw manifold egt's above 1550 EVER. it runs safely rich. recently, my head gasket blew, causing pressure leakage under high load to seeep into the water chambers and spit water out, and heat it up during normal combustion. this caused it to spit 80% of the water out and only be cooled by the remaining 20 % through a fluiddyne radiator and teh engine oil (which never got abouve 190 degrees). the engine oil usu. rose to abotu 150 degrees while driving with little water. now, the stock coolant temperature sensor is still installed, and I removed the head to check the gasket. there are signs that the gasket failed on the intake side fo the combustion chamber, and that side is "pretty damn clean" to say the least on all 4 cylinders. all pistons look "good" (not absolutely perfect, but not damaged). adn the compression face on the intake side between the 2 valves is beat to hell and back on all 4 cylinders. the o-rings around each cylinder wall are all flat from being compressed, and it almost looks kien the head gasket failed from detonation, even 'though the ONLY time I perpetually "beat" on the car to the extent of the oil temp ever exceeding 180 degrees I was running about 112 octane fuel and 18 psi. Facts: intake side shows signs of higher than normal heat. exhaust side shows "perfect running order" signs. plugs show signs of perfect running order. compression is above perfect 190 psi across the board, combustion chambers of head are beat to hell and back.

tell me why.

go.

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

I wired the accell dfi so that It didnt' require the msd to work...........car was 'fast as shit' to say the VERY least at only 18 psi. I am actually eager to get it running again.

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

>I wired the accell dfi so that It didnt' require the msd to work

1. What do you mean by that? How do or did you have msd hooked up to the dfi?

2. Was the stuttering at WOT or partial throttle?

stutering was "under boost"

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

Armond, i dont have an answer for ya about your engine trouble, that is truly baffling and i hope you figure it out. i just wanted to ask ya something. the owner of the shop i do all my work through and who also happens to be one of my real good friends, is a guy named Mace Ward. we were talking about HP figures for my car one day, and he mentioned that he used to talk to a guy named Armond back when he was first starting his business and he drove a Seabring. he said something about helping you pick out a strut bar or something??? anyhow, while he was at NOPI he "heard" of a red avenger putting down LOTS of HP and was wondering if it was you, which of course i told him it was... :-) if ya remember him, he wanted me to tell you hi for him.

dood, that sucks armond. I cant give you advice, cause as you know, you know this stuff better than most of us.... but I will stop by here to send you positive karma +k to aid in the rebuild....

Well, these are my thoughts for the moment (could be waaay off)...
The coolant enters the head on the exhaust side of the head over cylinder #1. Could it be that due to your insufficient amount of coolant, that somehow, you were getting more flow on the exhaust side than on the intake side... or even that by the time the coolant reached the intake side of the cylinders, it was already too hot..?? That could also explain a large jump in oil temps, since the oil galley runs on the intake side of the block and would get heated considerably there under excessively hot conditions...

Also, you say that you have had your head ported/polished to add more flow... I wonder if that could change the flow characteristics enough that if you were running pretty rich, you would get a slight amount of pooling of fuel before the intake valves. Then, when the intake valve opens, non atomized fuel is being dumped in with the atomized fuel and not combusting in a completely controlled manner. Either that, or there wouldn't be enough fuel really there combusting, and the non-atomized fuel keeps your egt's down and shows a rich reading on your o2 sensor making you think the car is running rich when it isn't.

These are sorta crazy off the wall ideas, but I figure its gotta be something crazy if you can't figure it out ;)

hmm. if that was the case, then #4 cylinder (fartest away from the water pump) would have the worst heat damage. it doesn't :(. #3 does. I don't think my head woudl promote fuel puddling. it is smooth as a baby's butt, and is basically a straight shot down from the injector to the valves. if it was not burning all the fuel in spurts, the un-used oxygen would also flow all the way through and cause instabilities in my air/fuel ratio on the "skips". that isnt' the case.


A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

Under non-boosted operation, coolant could enter the combiustion chamber in small amounts. Coolant doesn't compress (water). Ever hit the water at 60MPH? Hurt? Could be that the coolant leaking into your combustion chamber effectively "beat the crap out of" the intake side of the motor before vaporizing under combustion forces.

I'm totally grasping at straws here, but you asked..

it wasn't drawing in enough coolant to cause detonation when I let off the throttle and put the car in vaccuum. plus, all of that coolant would have been blown straight through the engine anyway due to 0 load. at all other times, cylinder pressure was pushed under the head gasket into the water chambers.

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

This kindof comes back to my theory. Running that rich, the A/F mixture isnt combusting properly. You may have even experienced some pre-ignition, not just detonation. With coolant flow problems, even if the actual coolant temp is normal, the temp at the cumbustion chamber can be much higher. This causes detonation, even running 5 degrees retard, and 112 octane gas. This is just a guess. Matt_95tgs has some good theories also, with how the coolant actually flows from the block to the head. If damage is on the intake side of the head/block, then that seems to me it was caused by too hot of coolant/insuficient cooling. I want to make sure i read that righ, that the cylinder head cumbustion chamber itslef was damgaged at the intake side, or the piston tops were damaged at the intake side? This again brings me back to my "theory" that we need to pull more timing out over 15 psi, closer to around 15 degrees. I think back to basic physics, that when a compressed gas is starting to be released of pressure (later ignition spark after max compression takes place in the cylider), that the temperature of the gas goes down. Another idea, is that without the spark ignition amplifier, that a poor, weak spark coulnt ignite the mixure well enough, to cause incomplete, or improper fuel burn, aka, detonation.

Another theory:
You got detonation, and blew the HG on the coolant side of the block/head passages. Now, we have that extreme cumbustion pressure leaking out at the coolant passages. Think about this. Air displaces water, thats a fact. If pressure is pushing out coolant from the block/head, then you will have almost NO coolant in the head and/or block when its happening. This means that oil alone is trying to cool the cumbustion chamber. Chamber temps are skyrockting, and then all that extra heat is causing even more detonaton, damaging the metal surfaces. The damge is contained by the HG leak area, becuase this is where cumbustion pressure is leaking. Just another thought...

I seriously doubt I was getting pre ignition. if I was, it woudl have been quite audible on the dyno (both myself and ed listened for it closely, and all we herd was belt noises and such. no clacking to speek of. that air/fuel ratio is consistant with what most other high hp boosted cars run with consistantly everyday. when I tuned for leaner than that, I was burning holes in pistons to say the least. I think your second idea is a little better.

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

Domed pistons or dish pistons?

Either way, did you massage the top of the cylinder head?

Which side does the mixture compress to..

How do the valve seats look?

Which cams are you using? overlap?

Here's the deal..

The intake valves are different than the exhaust valves.. depending on your cam overlap and your piston top design (and if you've modified the head at all) the mixture will be compressed to one some more than the other side.

The intake side of the head is designed to run cool, the exhaust side to run hot.. If your compressing the mixture to the intake side you will incurr damage on that side of the head as it will have to absorb the majority of the heat. It's not designed to do this.. stock it's designed to center the charge on the plug.

Also, if an injector is leaking or just dumping way too much fuel it's possible that it's running down the intake and pooling around the head gasket.. you mentioned o-ringing the head.. is the o-ring too big and the gasket not sealing at the head/cylinder wall.

Lotsa variables..

Just read what you wrote again.. possibly relecting too much heat back at the cylinder head? ceramic coat the head.. and/or you need to take out more timing.

-- WheatKing

i would suppose it would depend of the holes, dimples aetc or what the head has on it is from heat which can very well be ive melted a few heads on various motors before running lean and hot, or if it was from trying to compress somthing that is solid..

on the heat subject u could be reflecting to much heat back to the head being the intake side doesn't release heat via a valve the exhaust side does so when it (ceramic coating) is pushing the heat away it go right into the intake side and stays there

leaky, not fully balanced injectors and or fuel mapping could be the problem i second the weak spark theory,

are your orings metal or rubber?

the o-rings are copper. the fuel system is rock solid. been check and tested multiple times, and holds consistant air/fuel ratio under wide open throttle.

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

>Domed pistons or dish pistons?

dished je 8.8:1 ceramic coated forged pistons. .040 overbore

>
>Either way, did you massage the top of the cylinder head?

originally the cylinder head chambers were polished. the intake half now looks like the surface of the moon (slight exageration, but you know what I mean)

>
>Which side does the mixture compress to..

I am assuming in the center of the combustion chamber. I haven't changed extreme characteristics of the motor that much. it is still a basic 420A powerplant.

>
>How do the valve seats look?

I haven't removed the valves yet, but they did not leak a considerable ammount during the leak down test. little pressure was relieved through the head gasket (hince the overheating)

>
>Which cams are you using? overlap?

crane turbo-spec

minimal.


>
>Here's the deal..
>
>The intake valves are different than the exhaust valves..
>depending on your cam overlap and your piston top design
>(and if you've modified the head at all) the mixture will be
>compressed to one some more than the other side.
>
>The intake side of the head is designed to run cool, the
>exhaust side to run hot.. If your compressing the mixture
>to the intake side you will incurr damage on that side of
>the head as it will have to absorb the majority of the heat.
>It's not designed to do this.. stock it's designed to center
>the charge on the plug.
>
>Also, if an injector is leaking or just dumping way too much
>fuel it's possible that it's running down the intake and
>pooling around the head gasket.. you mentioned o-ringing the
>head.. is the o-ring too big and the gasket not sealing at
>the head/cylinder wall.

the o-rings seald on the previous setups with the stock mls gasket. this time I had msd ignition problems where the power would be unstable.

injectors were tested before the motor went together by rc engineering. no leaks, all outputting 720 +/- 3 cc at 45 psi.
>
>Lotsa variables..
>
>Just read what you wrote again.. possibly relecting too much
>heat back at the cylinder head? ceramic coat the head..
>and/or you need to take out more timing.

I think I will take your advice and get the chambers of the head ceramic coated this time around. thanks for the input.

>
>-- WheatKing

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

Got pics of the head? I would be very interested to see the marks you are talking about. I don't have any theory - yet.

yea pics of the chambers will help us determine excessive hat to bug up the chambers or if it was an object =)

I wish I had some pictures, but I don't have a digital camera, so photos become quite a chore for me (I still have plenty of photos from the shootout that I haven't developed yet :( )

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

>I wish I had some pictures, but I don't have a digital
>camera, so photos become quite a chore for me (I still have
>plenty of photos from the shootout that I haven't developed
>yet :( )
>

Speaking of the shootout, Armond, did you run there? I have about a good 40 minutes of drag racing footage i shot when i was there...If so, which car were you again?

I had the black Dosge stealth w/ the chrome 19x9 axis se7ens. I broke on my second run drag racing. I did autocross all day the day before 'though.

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............