whats a sign of detonation? pitting?

dont ant to hi-jack the thread but in the couple of motor i've pulled aart i've seen nothing unusual at all

yeah, looks as though you had some head gasket issues between 2 and 3. rallycar, if you suspected that you had done rings, you would have needed to take the pistons out to see any signs of it.

If it was really bad the plugs would be stuffed as well.

Also so it doesnt look like your getting very good fuel air distribution across the cylinders.(Poor manifold would be my guess)

It ran to 250+degF, blew a head gasket and was filling up with water, what was left in there, I wouldnt read to much into the burn tracks...

It made nearly 100kw atw so couldnt have been to bad for a stock A12 motor???

Here is the manifold...

Quote:

it quite normal for the piston under the inlet valve to be cleaner than the exhaust side. all that fuel air mix rushing in on that side tends to keep it cleaner.

yes, some crossfiring between 2 and 3, but he did say the headgasket blew. It certainly wouldn't have been running like this before the headgasket went. this type of head gasket failure makes the engine run very rough and makes alot of noise.

fair enough, so the head gasket was gone! i reckon you are proving what many have tried to before that a well thought out system will provide great results and when there is failure it is not due to the weaknesses in an a series rather the way the turbo has been set up.

great work mate!

Im positive that had the radiator been bigger and stopped it from overheating it would still be going fine...