Think I blew a head gasket?

[Flyin Brian]

I think I pushed out number 6 today. I have never blown a head gasket before but it sounds like what you think a blown head gasket would sound like. 24 psi boost with very minimal knock retard and it started making a very loud whistling squeaking sound on the passenger side of the motor. Got out and opened the hood and it sounds like running the motor with a spark plug removed. Pulled all the plugs on the passenger side and number 6 looked like it may have had a bit of water on it. I don't have a leakdown tester but the compression tester showed that cylinder to be 30 psi less than the 2 cylinders next to it. At least I did not throw a rod.

 

[BEATAV8]

what kind of gasket? Cometic?

 

[Flyin Brian]

Yes they were Cometic. Only had about 1000 miles on a fresh rebuild. I did not assemble the longblock. My engine builder did. Previous build with the same gaskets seemed to be bulletproof. I did a lot more wrong to the last build than I did to this one. Gasket really seemed easy to blow. Maybe they did not get torqued down good this time. I may try to check the head bolt torque on the other side on a bolt that I can get to easily. I won't have a chance to tear it down for a couple of weeks.

 

[jasjamz]

80lbs injectors do not fit that combo at 24 psi...
A/F Ratio target?
Duty Cycle?
What plug were you running?
Volt Booster?
Any logs??

 

[Flyin Brian]

It was lean. I was trying to keep it around 11:1 or less on the gas scale (not running in wideband mode) and it could do it at 20 psi boost. I only had 1 degree of knock at 24 psi when it let go. I have R43TS plugs gapped at .032". I have a volt booster. I had just turned up the base FP 3 psi before this drive but I was still at 11.7:1 AFR and 98% IDC so I was totally out of fuel at that point. I think I must have hurt it 2 weekends ago where I had a log I just looked at with 12:1 AFR, 95% IDC, 24 psi boost and a quick 8 degrees of knock which is where I bet I hurt the gasket first (thought I got by with it). It was about 20 degrees cooler outside today than when I last ran so that did not help. I have a third log when I was running 20 psi and everything was cool. It does not take much knock to hurt these things! It think I was able to run way leaner without getting into trouble in the past because I had the wrong converter on it and it was slipping bigtime i.e. less load on the motor. My new converter couples like crazy which puts more load on the motor and is thus less forgiving in the knock department. Looks like I have to go to 120 lb injectors and a modded ECM or turn it back to 20 psi boost and turn up the FP a little more. I have attached todays and last months PL files.

 

[turbo89]

It was lean. I was trying to keep it around 11:1 or less on the gas scale (not running in wideband mode) and it could do it at 20 psi boost. I only had 1 degree of knock at 24 psi when it let go. I have R43TS plugs gapped at .032". I have a volt booster. I had just turned up the base FP 3 psi before this drive but I was still at 11.7:1 AFR and 98% IDC so I was totally out of fuel at that point. I think I must have hurt it 2 weekends ago where I had a log I just looked at with 12:1 AFR, 95% IDC, 24 psi boost and a quick 8 degrees of knock which is where I bet I hurt the gasket first (thought I got by with it). It was about 20 degrees cooler outside today than when I last ran so that did not help. I have a third log when I was running 20 psi and everything was cool. It does not take much knock to hurt these things! It think I was able to run way leaner without getting into trouble in the past because I had the wrong converter on it and it was slipping bigtime i.e. less load on the motor. My new converter couples like crazy which puts more load on the motor and is thus less forgiving in the knock department. Looks like I have to go to 120 lb injectors and a modded ECM or turn it back to 20 psi boost and turn up the FP a little more. I have attached todays and last months PL files.

Set your Base @ 52psi .. that will get the DC in the 80's ... with your boost level . There is no problem running those injectors at that fuel pressure.. they actually perform better.

Use the pumps to fuel the car not the injector DC

 

[Flyin Brian]

I think my base was around 52 psi on that run.

 

[turbo89]

I think my base was around 52 psi on that run.

I would check it to make sure ... you cant go much beyond 55 .. at that point your done with the injector .. I also just noticed that's a 4.1 and not a 3.8 ...

I would also pull a degree of timing out in the upper gears ..

 

[Chuck Leeper]

We run that inj at 4 bar, [LS psi], and it performs very well. Is right at a 94# flow @ 4 bars.
I have run many sets on the bench, and had a good pattern @4 bar.
There are hi imp 120's available, if you choose to step up.

 

[jasjamz]

I see your logs show a drop in engine vacuum at idle now. Did you notice that?
Its been argued before about the limit of 80's and E-85. Guys with 235ci motors reached the 100% DC under 24 psi if they spun the engines a little higher. I sure did!
You can raise the FP and blow another set of gaskets, or do the right thing and step up to 160's or 120's.

 

[BEATAV8]

good thing about cometics, when they're hurt they just start to leak a bit and you don't have to deal with the drama of dumping all the coolant into the crankcase due to a major blowout.

 

[Flyin Brian]

I see your logs show a drop in engine vacuum at idle now. Did you notice that?
Its been argued before about the limit of 80's and E-85. Guys with 235ci motors reached the 100% DC under 24 psi if they spun the engines a little higher. I sure did!
You can raise the FP and blow another set of gaskets, or do the right thing and step up to 160's or 120's.

I had not noticed the drop in engine vacuum at idle. I guess that means that I definitely lost a head gasket? Changing the head gaskets with the motor in the car is going to suck but I guess people do it all the time. I won't be able to start the teardown until Tuesday night. Got to order gaskets. Cometics have gotten expensive! I have the 060" to get 9:1 and it is $30 more each than the 040" so I am looking at $260 for a pair. Throw in the intakes and I spent $300 on this tuning mistake. Still way cheaper than an entire rebuild.

 

[Flyin Brian]

We run that inj at 4 bar, [LS psi], and it performs very well. Is right at a 94# flow @ 4 bars.
I have run many sets on the bench, and had a good pattern @4 bar.
There are hi imp 120's available, if you choose to step up.

Hey Chuck, where can I get the high impedance 120's and are they any good?? I have heard bad things about the high impedance 160's and even the people that sell them do not recommend them. Do you think the 120's will get me safely to 28 psi (where my turbo should be most efficient) with my combination?

 

[Flyin Brian]

good thing about cometics, when they're hurt they just start to leak a bit and you don't have to deal with the drama of dumping all the coolant into the crankcase due to a major blowout.

Thus far I have found no water in the oil. I did not blow any oil out either that I can find. Hopefully I did not hurt anything else like a rod bearing. I think I got lucky this time.

 

[BEATAV8]

torque

Thus far I have found no water in the oil. I did not blow any oil out either that I can find. Hopefully I did not hurt anything else like a rod bearing. I think I got lucky this time.

Yep you'll know for sure once you get it apart but I bet you'll be able to just clean it up, put it back together, change the oil and be good to go (along with some more fuel, lol)

You gonna pull it out and go through top to bottom, or just swap the gaskets in the car?

 

[Flyin Brian]

torque
Yep you'll know for sure once you get it apart but I bet you'll be able to just clean it up, put it back together, change the oil and be good to go (along with some more fuel, lol)

You gonna pull it out and go through top to bottom, or just swap the gaskets in the car?

I really just want to swap the gaskets in the car unless I find something scary when I start the teardown. Shortblock only has about 1000 miles no it. Forged pistons, K1 rods, K1 crank, steel center caps with all ARP main studs. ARP head bolts too and a BHJ balancer. Durabond main and rod bearings with Mobil 1 10W40 and ZDDP. Motor was up to temp and so was the oil when it happened. Oil only had about 300 miles on it with little boost time so I hope I did not damage a bearing.

 

[turbo89]

We run that inj at 4 bar, [LS psi], and it performs very well. Is right at a 94# flow @ 4 bars.
I have run many sets on the bench, and had a good pattern @4 bar.
There are hi imp 120's available, if you choose to step up.

I have also but it starts to get touchy if you cant pull out some on the bottom.. with the setup he has he can do it ..

I would up the FP and watch your tune.. there is still fuel left in that injector for 24 psi ... Im not sure it be enough for 28 psi like you mentioned .. but that car has to be trapping over 130
using that much injector at this point.

 

[Flyin Brian]

Ok, I got a chance to work on it a little bit tonight. I pulled all the plugs and disconnected the fuel pumps. I sprayed WD40 in all the cylinders and turned it over a few times in case any corrosion might be starting in a cylinder due to water or E85. Drained the oil and it looked good, no water. Drained the radiator and it looked good, no oil. Took the oil filter apart and it is the best it has looked since my last rebuild 1000 miles ago. No metal or anything. Checked the turbo and no endplay or leaking oil. I was able to get up underneath the car and take some pictures. It appears to be real obvious where the gasket blew. Check it out.

 

[BARRACUDA1968]

I feel your pain.....I feel your pain!

 

[BEATAV8]

Yep I've seen that before lol