What could it be???

[TurboV6Olds]

Hoping someone could give some ideas about what might be wrong with my car. For some reason I can't keep the car together more than a year and I don't drive it that much. After the rebuild the car may have 1200 miles on it. Last fall I ran the car down the track and run my best time @ 11.60 but had smoke about half track. I had zero knock running 18 psi boost with 100% methanol injection at about 17 deg. of timing. The car seemed to run strong the entire run and even felt good on the way home. I drove the car the following weekend about 25 miles and everything seemed good then as well. My buddy called wanting me to take him for a ride the following weekend so I went out and started the car and was letting it warm up. I popped the hood making sure everything looked OK and sounded OK. I noticed a noise coming from the drivers side valve cover so I popped the K&N breather out of the valve cover and heard a spitting sound like a valve may be open or something causing compression to get back into the valve cover. I have not done a compression or leak down test yet. I will start working on it in the next few weeks just wanting to know if anyone had any ideas to make it easier to diagnose the problem? The car has Cometic head gaskets that have been used twice. The block has been decked and the heads have been cleaned up as well. The motor is stroked and bored .030. My machine guy says the motor has about a 9.8 - 10.0 : 1 compression ratio if this makes a difference.

Thanks in advance for you response,
Rick

 

[Phoneguy]

I would start with a compression test. Cometics dont normally blow per se but I have lifted them several times. Good luck

Bryan

 

[TurboV6Olds]

OK, I finally got the intake off the car after doing a compression test and loosing air on #1 cylinder. It appears on the Cometic gasket where the rivet is at the front of the head is where it let loose. Does anyone have any idea of what the best head gasket is to buy ?
Thanks, Rick

 

[Phoneguy]

Post a picture. At 17* and 18 psi you are no where near on the edge. How's the fuel pressure ? How much torque in the head gaskets? Bolts or studs ? Retorque after heat cycle ? Something doesn't add up here. Timing verified ?
I have lifted cometics and completely melted a head, piston , block and push rods bit my boost was probably double yours.
Bryan

 

[TurboV6Olds]

Post a picture. At 17* and 18 psi you are no where near on the edge. How's the fuel pressure ? How much torque in the head gaskets? Bolts or studs ? Retorque after heat cycle ? Something doesn't add up here. Timing verified ?
I have lifted cometics and completely melted a head, piston , block and push rods bit my boost was probably double yours.
Bryan

Here are pics of the gaskets still on the car. I was running 18 psi with 17 deg. of timing according to the power logger. I'm not sure of the fuel pressure during the run but I have checked in the past and had about 60 psi with that 18 psi boost. I have ARP head bolts that have been removed about four times and reinstalled. The heads were not retorqued after heat cycle because I was told I did not need to with cometics. I checked the torque on the heads and it is around 85 ft. pounds on all head bolts. Thanks for your time in helping me, Rick

 

[TurboV6Olds]

Here are pics of the gaskets still on the car. I was running 18 psi with 17 deg. of timing according to the power logger. I'm not sure of the fuel pressure during the run but I have checked in the past and had about 60 psi with that 18 psi boost. I have ARP head bolts that have been removed about four times and reinstalled. The heads were not retorqued after heat cycle because I was told I did not need to with cometics. I checked the torque on the heads and it is around 85 ft. pounds on all head bolts. Thanks for your time in helping me, RickView attachment 163094View attachment 163095View attachment 163096View attachment 163097View attachment 163098View attachment 163099

A couple of the pics are of the HG at the back of the head just to show the difference between the front and rear of the HG. A couple of the pics needed to be rotated as well sorry for that.
Rick

 

[Phoneguy]

What do the plugs look like? How much ALKY ?
I dont see any signs that the head gaskets were sprayed with copper or hylomar. Did you install these dry after using them previously? You need to VERIFY your timing. What fuel pump and injectors? What chip?

Bryan

 

[TurboV6Olds]

What do the plugs look like? How much ALKY ?
I dont see any signs that the head gaskets were sprayed with copper or hylomar. Did you install these dry after using them previously? You need to VERIFY your timing. What fuel pump and injectors? What chip?

Bryan

Plugs looked good. I did not install the HG, my machine guy did. The Alky is set on about 6 and I use methanol instead of Alcohol. The HG have been used I think twice or maybe three times. How do I verify the timing? Hope this is not a dumb question. The chip is a TT 93 w/ alky @ 17 Deg of timimg and 17 psi boost. I have not changed the timing through the scanmaster so how else can i tell? With a timing light? I can post pics of plugs if needed? The pump is a Walbro 340 with stock supply and return lines. Do the lines need to be increased? If so what size?
Thanks, Rick

 

[Phoneguy]

ALKY is just a term...Most people use Methanol. Yes verify your timing with an adjustable timing light. Post a pic of the plug in the number 1 cylinder and one other. I personally would never re use a Cometic gasket. Re using without a coating is just crazy to me. Why the 5 layer gasket, trying to lower compression?

Bryan

 

[RmvBfrFlght]

Unfortunately that HG is leaking, can see the carbon on the rivet and tab in the first picture (but I think you already know this). Recent thread:

http://www.turbobuick.com/forums/threads/which-head-gaskets-best.378333/

Ken (turbofabricator) recommends a Fel-Pro HG. They are what I would use.

RemoveBeforeFlight

 

[TurboBob]

did you hit a rev limiter when running at the track?

The rev limiter in the chip cuts off the injectors, but your alky system will keep spraying, the result is usually breakage of one flavor or another.

Bob

 

[TurboV6Olds]

did you hit a rev limiter when running at the track?

The rev limiter in the chip cuts off the injectors, but your alky system will keep spraying, the result is usually breakage of one flavor or another.

Bob

No I did not hit rev limiter. The car was turning around 5400 Rpm @ 1/4 mile the best I remember. I will check powerlogger and let you know for sure. Thanks, Rick

 

[TurboV6Olds]

ALKY is just a term...Most people use Methanol. Yes verify your timing with an adjustable timing light. Post a pic of the plug in the number 1 cylinder and one other. I personally would never re use a Cometic gasket. Re using without a coating is just crazy to me. Why the 5 layer gasket, trying to lower compression?

Bryan

Here are pics of plugs. You can tell which plug is number one and the other is from 3 or 5.

 

[TurboV6Olds]

Ttt

 

[RmvBfrFlght]

My2-cents worth, first, need to go with colder plugs. They are on the hot side, try one heat range colder.

The clean plug, that one looks to be free of detonation.

The wet looking plug, that could be signs of detonation. Or, it pulled some oil in from the lifter valley from the leaking head gasket. See the little black specks, that is usually from detonation. But in this case it could also be from the oil getting in past the head gasket.

RemoveBeforeFlight