white smoke

[Starlight]

If you dont have a fuel knock it sounds like coolant in the cylinder. I did an engine recently that had those same symptoms and had the cylinder head cracked. White smoke was mostly when sitting overnight. Coolant pressure after shutdown was higher than cylinder pressure and it leaked into the chamber while sitting. Next morning engine was started, out came that coolant as white smoke, ran like garbage then cleared up and ran fine. The rest is history. Not saying your issue is the same but at this point expect anything.