Why would you want to over fill by 0.5L? It will rob power and be bad for the engine. If anything you find that track cars (proper race cars) will try and run with the absolute min of engine oil in there. Graham Bell gives a good explanation in his book 4 stroke performance tuning about why you should not overfill the engine, indeed according to him he would run it underfilled (only though with some testing for surging / extra work on the sump etc to prevent this). One or two lines from the book:
"Having considered the foregoing information (previous paras giving other info) it should be obvious that the sump should never be overfilled , otherwise you are sure to have the crank and rods dipping into the oil every revolution. If that is not bad enough, you will end up with a situation where too much oil is being thrown up the cylinders ; the rings will have to drag it off the walls and that consumes power. If the rings cannot cope with this additional oil load you will have combustion chamber and plug oiling problems, which will affect combustion and rob you of performance"
Is 300ml to much? eh possibly but it is less than 10% overfilled. personally if it was my car I wouldn't be too concerned.
Pictures of the potential engine destroyer are requested for the lads to rate
unless she was wigling her ass i supose
