Head gasket problem? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Super73 · 04-10-2008, 02:01 AM

Backround:

347ci forged roatating assembly. (LS!)
Ported 843 heads (Used off a buddies car)
Trex
Cometic .045 gaskets
LS6 intake
Ring gap and piston was left a little loose as I planned on spraying a 300 hit on the motor.

Valve covers flipped (driver on pass / pass on driver) with a single breather out of the hole that is normally used to go back in to the intake.

Made a 100 shot bottle pass this weekend and ended up with water in my engine compartment. It looked like I lifted the radiator cap (16lb).

Since day one I have had slight steam emit from the breather. I have some condensation build up in both valve covers but no water in my oil during oil changes and no milk shake. I do have a little milkyness under the covers sitting in the heads. I now have a little oil build up on the radiator car and it has always consumed a little bit of water.

The block was decked when the machining was done and the fact thatt he heads came off another buddies car that had no issues, I'm leaning towards head gaskets not seating properly during instal.

Obviously the heads need to come off, but any suggestions prior to pulling them off? Any other things you suggest looking at before, during and after pulling the heads?

Like compression test to see if I can isolate the cyl.

Here is the breather set up:

Here is the build up in the valve covers. Again, there was nothing during last oil change (1 week ago preping for the track), but there has always been some build up with the breather and steam no matter how hot the motor is.

70rs/ss · 04-10-2008, 07:37 PM

Try a cylinder crank test to see if one or two cylinders are down, how do the plugs look? Did you use ARP bolt or factory fasteners? I have heard the LS motor have issues with pcv, but this is water in the oil no doubt, I'll bet the gasket is popped somewhere. The spark plug may tell which cylinder, look for a white plug (Steam or water will clean the electrode) you may even find water in the cylinder. How long did you run it? One last thing with as much squeeze at you want to use did you O-ring the block? Nitrous builds lots of cylinder pressure and an O-ring can contain it. I am no expert on the LS motors, but a head gasket blowing is a universal problem with any motor, and the O-ring is one solution?

Super73 · 04-10-2008, 09:20 PM

The motor with the old heads cam package never lost water and never had condensation from the breather. This heads cam package using cometic multilayer gaskets, I have always lost a slight bit of water and always had a little steam from the breather no matter how hot the motor was. This is making me think a head did not seat properly from day one.

All the plugs look the same. I pulled the plugs before the track, after one full day of racing and when I got home. Do detonation, not lean, nor rich. The 605's showed they were more correct as far as heat range NA. I only got to make one N20 pass. The 104's are definately too cold NA.

I think what is happening is there is a slight leak between the cooling passage and cyl. Do to the ring gap and tolerences on the piston/wall, I think I am pulling pushing a bit. On the 100 shot, I presurized the cooling system and lifted the 16lb cap.

Block is not o-ringed. I honestly wasn't going to put this much N20 through it originally.

Shaun

70rs/ss · 04-10-2008, 10:02 PM

It sounds like a head issue since that is all that has changed, but with loose rings, you would pressurize the crankcase and blow oil out of the breather, not into the cooling system. If you pushed the rad cap you blew a head gasket or you have a crack in the head or possibly a valve seat. The only way compression would get out of the cylinder and into the coolant is if something; head or gasket failed. Possibly the intake gasket (again not an LS expert) but it is possible (less likely than the head gasket, though) the intake gasket is allowing cylinder pressure into the cooling system, or coolant into the oil? Did you pressure test the cylinders? Pull all the plugs and kill the coils so the motors spins easy and listen while a buddy spins it over you might be able to locate the problem (by hearing it) or at least if you have a cylinder that is lower than the rest?

04-10-2008, 02:01 AM	#1
Super73 Registered User Join Date: Nov 2007 Location: Bay Area, Ca Posts: 2,841	Head gasket problem? Backround: 347ci forged roatating assembly. (LS!) Ported 843 heads (Used off a buddies car) Trex Cometic .045 gaskets LS6 intake Ring gap and piston was left a little loose as I planned on spraying a 300 hit on the motor. Valve covers flipped (driver on pass / pass on driver) with a single breather out of the hole that is normally used to go back in to the intake. Made a 100 shot bottle pass this weekend and ended up with water in my engine compartment. It looked like I lifted the radiator cap (16lb). Since day one I have had slight steam emit from the breather. I have some condensation build up in both valve covers but no water in my oil during oil changes and no milk shake. I do have a little milkyness under the covers sitting in the heads. I now have a little oil build up on the radiator car and it has always consumed a little bit of water. The block was decked when the machining was done and the fact thatt he heads came off another buddies car that had no issues, I'm leaning towards head gaskets not seating properly during instal. Obviously the heads need to come off, but any suggestions prior to pulling them off? Any other things you suggest looking at before, during and after pulling the heads? Like compression test to see if I can isolate the cyl. Here is the breather set up: Here is the build up in the valve covers. Again, there was nothing during last oil change (1 week ago preping for the track), but there has always been some build up with the breather and steam no matter how hot the motor is.

04-10-2008, 07:37 PM	#2
70rs/ss Registered User Join Date: Dec 2004 Location: Northern AZ Posts: 7,271	Re: Head gasket problem? Try a cylinder crank test to see if one or two cylinders are down, how do the plugs look? Did you use ARP bolt or factory fasteners? I have heard the LS motor have issues with pcv, but this is water in the oil no doubt, I'll bet the gasket is popped somewhere. The spark plug may tell which cylinder, look for a white plug (Steam or water will clean the electrode) you may even find water in the cylinder. How long did you run it? One last thing with as much squeeze at you want to use did you O-ring the block? Nitrous builds lots of cylinder pressure and an O-ring can contain it. I am no expert on the LS motors, but a head gasket blowing is a universal problem with any motor, and the O-ring is one solution?

04-10-2008, 09:20 PM	#3
Super73 Registered User Join Date: Nov 2007 Location: Bay Area, Ca Posts: 2,841	Re: Head gasket problem? The motor with the old heads cam package never lost water and never had condensation from the breather. This heads cam package using cometic multilayer gaskets, I have always lost a slight bit of water and always had a little steam from the breather no matter how hot the motor was. This is making me think a head did not seat properly from day one. All the plugs look the same. I pulled the plugs before the track, after one full day of racing and when I got home. Do detonation, not lean, nor rich. The 605's showed they were more correct as far as heat range NA. I only got to make one N20 pass. The 104's are definately too cold NA. I think what is happening is there is a slight leak between the cooling passage and cyl. Do to the ring gap and tolerences on the piston/wall, I think I am pulling pushing a bit. On the 100 shot, I presurized the cooling system and lifted the 16lb cap. Block is not o-ringed. I honestly wasn't going to put this much N20 through it originally. Shaun

04-10-2008, 10:02 PM	#4
70rs/ss Registered User Join Date: Dec 2004 Location: Northern AZ Posts: 7,271	Re: Head gasket problem? It sounds like a head issue since that is all that has changed, but with loose rings, you would pressurize the crankcase and blow oil out of the breather, not into the cooling system. If you pushed the rad cap you blew a head gasket or you have a crack in the head or possibly a valve seat. The only way compression would get out of the cylinder and into the coolant is if something; head or gasket failed. Possibly the intake gasket (again not an LS expert) but it is possible (less likely than the head gasket, though) the intake gasket is allowing cylinder pressure into the cooling system, or coolant into the oil? Did you pressure test the cylinders? Pull all the plugs and kill the coils so the motors spins easy and listen while a buddy spins it over you might be able to locate the problem (by hearing it) or at least if you have a cylinder that is lower than the rest?



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