Poof... Goes the head gasket

[trbodon21]

Well Had my 4.1 out yesterday doing some tunning on the highway. This was the first time out tunning the Gen. 7. and the first time actually putting any boost throug it. Car was running good alittle on the hot side (195*), still waiting for my Dual RC fans, but any ways I was slightly getting into it doing some 10 to 13 psi pulls for a few seconds. The car felt very responsive and very strong. Did another 13psi pull at about 1/2 to 3/4 throttle felt real nice and after I let off I looked back and there was a 40 ft. trail of burning antifreeze. We had the wideband on it when tunning it and kept it nice and rich around 10.5 on the AF just to be safe. The tunner was in the passenger seat watching everything the whole time and said that everthing was within normal operating conditions. I was easy on her all day. There was no knock nothing out of the ordinary. However I was using felpro 1000's, which was my first mistake. I'm hoping that it was useing these cheap gaskets that casued the problem and not something wrong with the block. The block has been decked and the heads were done as well.

Its going to get torn down later on this week. I was told that Cometics are the way to go. I'm going to be running around 20 to 22 psi at the track so I don't think it is necessary to use the steels.

Does this sound like just problems with the gaskets? Are cometics the way to go? Where are the best vendors for cometics?

 

[noslo6]

Felpro 1000s

I had almost the exact same experience. I recently did a rebuild with ported heads and forged pistons. I installed head studs hoping to help keep the heads seated. Second or third time out driving with like you said 10-13 psi boost, I got a milkshake in the engine. Did a compression test and had blown a gasket. No knock and plenty fat to keep egt's down. I was so pissed off, but didn't want to pull the other head to replace both gaskets. So I replaced the blown (drivers side luckily) and went back out. Very next time out popped the passenger side. I vowed never to use a Felpro 1000 again. I used a single steel coated with GE1000 silcone and have been hitting it hard ever since up to 25 psi - no problems. As far as I'm concerned, the 1000's just suck for this application.

 

[norbs]

I blew out those gaskets composite grey style gaskets in seconds, shim steel is the way to go period.

 

[Intercooler]

Re: Felpro 1000s

Originally posted by noslo6
I had almost the exact same experience. I recently did a rebuild with ported heads and forged pistons. I installed head studs hoping to help keep the heads seated. Second or third time out driving with like you said 10-13 psi boost, I got a milkshake in the engine. Did a compression test and had blown a gasket. No knock and plenty fat to keep egt's down. I was so pissed off, but didn't want to pull the other head to replace both gaskets. So I replaced the blown (drivers side luckily) and went back out. Very next time out popped the passenger side. I vowed never to use a Felpro 1000 again. I used a single steel coated with GE1000 silcone and have been hitting it hard ever since up to 25 psi - no problems. As far as I'm concerned, the 1000's just suck for this application.

The steels opening isn't large enough for a 4.1 so you must have them on a 3.8. If you have them on a 4.1 please let us in on how you got the fire ring hogged out enough?

 

[Intercooler]

Originally posted by trbodon21
Well Had my 4.1 out yesterday doing some tunning on the highway. This was the first time out tunning the Gen. 7. and the first time actually putting any boost throug it. Car was running good alittle on the hot side (195*), still waiting for my Dual RC fans, but any ways I was slightly getting into it doing some 10 to 13 psi pulls for a few seconds. The car felt very responsive and very strong. Did another 13psi pull at about 1/2 to 3/4 throttle felt real nice and after I let off I looked back and there was a 40 ft. trail of burning antifreeze. We had the wideband on it when tunning it and kept it nice and rich around 10.5 on the AF just to be safe. The tunner was in the passenger seat watching everything the whole time and said that everthing was within normal operating conditions. I was easy on her all day. There was no knock nothing out of the ordinary. However I was using felpro 1000's, which was my first mistake. I'm hoping that it was useing these cheap gaskets that casued the problem and not something wrong with the block. The block has been decked and the heads were done as well.

Its going to get torn down later on this week. I was told that Cometics are the way to go. I'm going to be running around 20 to 22 psi at the track so I don't think it is necessary to use the steels.

Does this sound like just problems with the gaskets? Are cometics the way to go? Where are the best vendors for cometics?

Dumb question but what did you use for bolts or studs? Is this a production motor? Takes shorter bolts.

The 1000's if you ask Fel-Pro are NOT high performance gaskets. They aren't intended for high boost or cylinder pressure although people get away with it.



I am changing a set of steels in my car tomorrow because one got heart early on. I will put up pics. Because you have to torque them all the time I can't stand them. I am going back in with Cometics and I have a picture of my 4.1 as it sits with the Cometics on it I will put up here in a second.

 

[Intercooler]

Get the Cometics!

http://home.comcast.net/~intercooler2/DVC00353.JPG

 

[trbodon21]

Thanks for the info. This is just a 4.1 out of one of the 84 cars, .020 over with the stock GN heads ported, stock bolts etc... I am going to go with the cometics. The only reason I had felpro 1000's in there was because I wasn't sure what to use and called a vendor (I won't mention the name) and asked if these gaskets would be good enough for my set up. They said yes so I went with them and learned my lesson. How much do the cometics usually cost?

 

[Intercooler]

I picked up two sets recently.... the 4.1 and my 3.8 that I am changing tomorrow. I paid $116.00 a set.

 

[noslo6]

I'm sorry, mine is a 3.8 not 4.1, but my "experience" with the gaseket was the same. I've got a freind who tried the cometics on his GN and they worked ok, but he's since switched to the single steel with GE 1200 like me. I have no experience with 4.1's and didn't realize the steel gaskets wouldn't fit, I was only stating I had a similar case with the gaskets.