Originally Posted by Brutus1967
Second: if an engine is "broken in" and operated on castor oil, it CAN fail when using synthetic.... that is also a very possible outcome if you take the wrong approach....
But the statement that an iron piston in a steel liner MUST be lubricated with castor, is just utter BS.
I have seen brand new Enya engines which where run in with synthetic oil from the start, and they just wear out straight away. There is simply no substitute for castor, a blend might be fine though.