what causes damage in 1 cylinder.

[Trip]

Car was smoking blue (oil) as seen on this clip

http://s131.photobucket.com/albums/p298/Trip_gtir/?action=view&current=mtahleb001.mp4 @00:19

and on this

http://www.youtube.com/watch?v=N7ZFT_d2cfI @ 09:15

Did a cold compression test and got

60psi, 149psi, 152psi, 150psi

Added a tablespoon of oil in all 4 cylinder and got

100psi, 200+psi, 200+psi, 200+psi


Conclusion
Piston and/or cylinder #1 is damaged.


I had done a compession & leakdown test 3 races ago (around 10min of total racing) and all 4 cylinders where in the 150psi mark. Spark plug on Cylinder 1 has a good and same burnt colour of the other 3. Oil pressure is fine too. AFR (measured from after the turbo) is 11.8 AFR @ WOT. Injectors are all working as i checked using datascan by stopping 1 injector at a time.

Running 1bar of boost and the occasion 1.2bar on a GT2860RS with chipped (Field Access) ECU and 102 octane fuel. Pistons are JE's


What could have caused such damage to #1 and not to the other 3 ?


Thanks

 

[red reading]

dodgy injector

 

[Trip]

dodgy injector

Thats what i thought too.. but wouldn't the colour on the spark plug #1 be slightly lighter in colour if I had a dodgy injector and running lean on the cylinder ?

 

[red reading]

does nt have to be far out to cause damage over a long period of time, plugs only tell you to a point

 

[stumo]

and unleaded fuels are crap for colour indications....