your piston looks much better than the one I had,
I had no method of checking detonation, only thing I know is that fuel ratio was ok
, and other car with stock rods and the same parts has worked ok with the same spark advance table
I use an aem ecu, dont know how to check detonation with it
thanks for the input

 

you're using a full custom engine, 30psi, race gas worth $$$ per litre and you have no form of knock/detonation detection?

oh boy

 

what do you use mike ?

 

+1 for detonation, the small white particles you see built up on the piston are usually tell-tale signs of detonation.

 

i get a professional tuner to tune my car.

he uses this

http://www.linkecu.com/products/Tuni.../g4-knockblock

 

100% detonation!! cause unknown......

 

On that pict and the other one it looks like dett, Can you take a pict of the other pistons for a better look.

Mark

 

Old threadi know but op never said if valves were hit or not.
Can you verify Thanks Op

 

The valves should not have hit. The debris from the piston may have hit the valves and seats.

 

Hi mate just wandering if you know this for a fact.only reason I'm asking is I just bought Manley stroker pistons and I'm planning to get Manley 156mm rods to go with my 94mm crank. Do you know someone running 156mm rods and stroker pistons with 94mm crank?

 

I had this issue with my Manley pistons, I changed it to CP and it worked fine.

Manley told me that my builder made a mistake with the pistons rings... Oh well...lesson learned