Is that normal for an engine with only 400 miles on it?
The story is that I built the engine and did everything correctly, primed the
oil pump, ran in the cam etc. engine fired first time and ran faultlessly for 400 miles until the exhaust rocker on no5 cylinder fell off (my fault I 'spose, what a muppet) and I drove the car (gently) 5 miles with the cylinder backfiring through the carb. removed rocker cover, nothing damaged or missing, so re-fitted the rocker. Engine started first time but with knocking (sounded like it was coming from the cam, but cam perfect)
I've now torn the engine down and can find nothing wrong (bearing-wise) apart from this scuffing on this piston.
I can appreciate that this piston was subjected to tremendous pressure and I would hope that's the reason for the damage, but is this what's causing my knock?
Have I stuffed these pistons/bores?
Everything else SEEMS to be nice and straight (H-beam rods, so I would hope they're OK)
any opinions most welcome.
Simon