What am I doing wrong?

[Jonpro03]

2 weeks ago tomorrow, I blew both head gaskets.



2 days ago, I finished replacing both gaskets with Felpro replacements.

I decided to take the TGP to class today in Indy. About 10 miles outside of Indy, some dude in a Mazda wanted to get his ass kicked. Middle of second gear, 50% throttle (too afraid to get on it all the way because I don't want to blow it up). 4psi of boost after a couple of seconds, into third. Smashed his ass.

Then dude starts flashin me. I see in his headlights a shit ton of smoke. I pull it over, shut it off, and sure enough, theres a lot of smoke coming out the exhaust, and under the hood. So I pop out the dipstick and the oil level is normal, a little low maybe. Last time this happened, coolant mixed with oil and the radiator exploded from the added pressure when the gasket blew. This time, I didnt even realize it blew. But I'm sure it blew because I can see pulses of smoke coming up out of the valve cover.

So I start it up and turn around to drive the half a mile back to the nearest gas station. Lots of smoke, running on 5 cylinders. I pull in and check the oil level again. 1 qt low. Still no coolant in the oil.

I figure I blew a gasket again, but I don't know where all the oil is going. Is the oil burning off in the combustion chamber and that's where all the smoke is coming from? Did a piston ring blow and I'm getting some serious blow-by?

The AFR was about 11.5, the coolant temp was 200*, I pulled 5* of spark timing after the first gasket blew. I was running 4psi when it happened.

The car is sitting in Indy right now. Tomorrow I'll tow it back home.

Are the factory gaskets (and replacements) really so weak that they are unable to handle 4psi of boost?

[90BlueZ]

2 days ago, I finished replacing both gaskets with Felpro replacements.

Your problem is right in your first sentence. My felpro HG lasted ~300km also. You can find a lot of horror story about felpro HG on this forum also.

Go with 04+ GM graphite gasket or cometic with arp head studs and you will never have to worry about HG anytime soon.

If you plan to run around 10-12psi, there is no reason the stock graphite gasket won't work, unless you have something else terribly wrong.

[Jonpro03]

Car is finally back in the garage. Tomorrow I'll tear it down and find out what happened.

[CNCguy]

If you lost the middle cylinders again, my guess would be lean or too much timing. From my understanding, the center cylinders tend to run leaner due to plenum design. With Aaron blowing the same cylinders, it would seem to make sense. Does MS allow you to do cylinder skewing?

At some point I want to verify this with some engine dyno testing/tuning with individual EGTs.

[90BlueZ]

Here is what I'm running for a individual cylinder knock control: http://www.jandssafeguard.com/

I'm also running MS3+MS3X

[Jonpro03]

Sorry, MS2 here. That means batch fire. I've been running it very rich though. Maybe I should go even richer?

I don't know, I'll wait and see what the problem is before I do anything.

[90BlueZ]

I'm running batch fire also. No problem running the J&S safeguard with batch fire if that's what you were thinking. 11.5 AFR is just fine, how many degree of timing ?

I have a feeling your problem is more then HG then the tune, but as you said we will see

Just trying to help there

[Jonpro03]

I appreciate the help. There's not a lot of MS 3x00 guys around.

Here's the spark table I was using when it happened.



Are you running a boosted engine? Care to share your tables?

[90BlueZ]

I pm'ed you my MSQ. I'm running a 3400 with 10lbs boost. Lot more advance too... about same afr around 11.6 at 10psi...

More info here: http://www.v6z24.com/registry/91z24

[Jonpro03]

Turbo3500.zip

Here's the AFR and Spark maps I'm using now if you want to go over them.

I'll have a looks see at yours! Thanks!

[90BlueZ]

The spark advance table looks fine, if anything its probably not optimal for max performance but I guess you don't care about that now.

The target AFR table tho, the MAP should go higher then 100 even if I understand the last row is what is used in boost. Take a look at mine for an idea, its probably not your problem but wouldn't hurt for sure

[Jonpro03]

I can take care of that. After going over your tables, I KNOW that there is nothing wrong with my tune as far as my motor blowing up. After the first set of gaskets went, I went over my tables and fattened them up to avoid blowing it again. But apparently that wasn't the problem.

Are you using MLS head gaskets?

[Jonpro03]

And why can't I find a price for the J&S Interceptor!

[90BlueZ]

I do have a set of cometic head gaskets but in my closet Right now i'm running 04+ GM head gaskets without issue.

The J&S safeguard is around 650$ (but worth every penny).

[Jonpro03]

Ah, the old saying holds true. If you have to ask, you can't afford it.