Originally Posted by coldfusion
Actually i've also added a 0.1 head shim before running on track as i was told it would protect the engine especially when it's still new and the compression is good. Is this correct?
more shims = less compression = less heat = happy engine, but you sacrifice a little engine performance.
Originally Posted by coldfusion
Need some indications on plug too - What if the plug is black or metallic like new? What does these indicate?
your engine is running nice and rich, as it should be when your breaking in an engine, if the glow plug wire is grey your running lean not good when your still running it in, if the wires distorted or damage your engine is running seriously hot!!
Originally Posted by coldfusion
Can i save the engine if the sleeve and piston has scratches or did i just blow my money??
depends how deep the scratches are, i've know a few people run engines with scratches on the sleeve and there engines still run well.
Originally Posted by coldfusion
More importantly - apart from monitoring engine temp when i head out to the track next, what else should i do to ensure i don't screw up the engine again.
Is there are simple process like check idle, then low end and only later adjust the main needle for top end?
ALWAYS make sure a good bit of smoke is coming out the exhaust, this indicates that your engine is getting enough lubrication. This IMO is more critical than keeping an eye on engine temperature. I doubt you have damaged your engine when you briefly ran it at 150c, as long as you were running it nice and rich.