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Pulled by heads because I was pushing coolant under boost... Found #7 piston to be almost perfectly clean, some slight carbon/discoloration, while all of the others had various levels of carbon buildup... Some of the buildup could be explained because my turbo scavenge pump wiring had an issue and my pump turned off and i got oil in my intake... But why is 7 so clean? Plugs were almost brand new as i changed them a few months before which cleared up a rough idle/miss under boost issue.
I pressure tested the radiator, only to 15 psi, and didn't have any leak down but i was definitely pushing coolant under boost. It was pushing it out of the overflow bottle.
Yep water. Seen it too many times to count. Figure out your pushing coolant issue, check your surfaces (block and head) stick it back together and you'll be golden. There's probably a 99% chance or better that whatever was causing the water push is also what caused the water in that cylinder. So when you fix one you'll likely fix both.
Yep water. Seen it too many times to count. Figure out your pushing coolant issue, check your surfaces (block and head) stick it back together and you'll be golden. There's probably a 99% chance or better that whatever was causing the water push is also what caused the water in that cylinder. So when you fix one you'll likely fix both.
Agree 100%. Can you post up a close up pic of that head gasket, particularly that cylinder? Both sides if you can.
I used to work at a speed shop that did failure analysis testing for Fel Pro
I NEVER use impacts to disassemble an engine. You need to “feel” consistency in the loosening process to understand what’s going on
Reverse torquing after intentional over heating is something we measured to report the gasket distortion characteristics.
I always pull torque bolts/studs up in four sequences
Twice through the initial 45. Then 55,65 etc. or 50,60,70. So the stepping up process is both equal and consistent
I do agree that the soft copper should be upgraded to MLS style where the outer layers can grab their respective surfaces and move around under boost. However you may need a fresh AND specific RA finish to be effective. Do your research and coordinate with your machinist
I used to work at a speed shop that did failure analysis testing for Fel Pro
I NEVER use impacts to disassemble an engine. You need to “feel” consistency in the loosening process to understand what’s going on
Reverse torquing after intentional over heating is something we measured to report the gasket distortion characteristics.
I always pull torque bolts/studs up in four sequences
Twice through the initial 45. Then 55,65 etc. or 50,60,70. So the stepping up process is both equal and consistent
I do agree that the soft copper should be upgraded to MLS style where the outer layers can grab their respective surfaces and move around under boost. However you may need a fresh AND specific RA finish to be effective. Do your research and coordinate with your machinist
I'm gonna have the heads checked out just to make sure everything is kosher... the block is an iron truck block that doesn't have a lot of miles on it and it was machined before it was put in the car. I don't know the exact Ra but the visual / fingernail check says its less than the 50Ra required for MLS gaskets.
To me this looks like the issue. The way that the copper appears to have discolored makes be believe it saw combustion gases and it goes around both water jacket passageways. But accoring to your description thats not the correct side? Is it possible that the picture is upside down and this is between 5 and 7?
Hi SS, yes we had the same problems with the Ford's cars that ran in France.
The first engines used copper gaskets that would leak water until the engine came up to temperature.
The cause, determined by FORD Engineering, was the fact that the Iron block/AL head growth caused the Gasket to "squeeze" Extrude itself.
The solution was the "undercut" the studs with agreement from Mike Costin (Cosworth).
I have no idea WHY ARP will make a correct stud (undercut) for many engines and NOT FOR the LSx engine ?
To me this looks like the issue. The way that the copper appears to have discolored makes be believe it saw combustion gases and it goes around both water jacket passageways. But accoring to your description thats not the correct side? Is it possible that the picture is upside down and this is between 5 and 7?
Nope... you're right that is the area between 5&7 on the head side. i marked it wrong. 5 was probably blowing into 7. Fixed the original post.
12-28-2017, 07:16 PM
One piston super clean 
