>>Acidity with diesel used to have alot to do with the sulpher in the fuel. Here in CA. we now have >>ultra low sulpher fuel. I'd guess that you have had that for a long time now? Where does the acidity >>come from besides sulpher?

>>Treven

I don't know ! If PAW reckon to leave the piston at the bottom of the cylinder for 2 to 3 days to allow acid byproducts to escape then.... I bow to their superior wisdom, 50 years worth I think it is !

The manufacturer of the oil I use in my car uses additives to ensure the oil can exceed the demands made on it by the diesel process.... they also make it alkaline to counter the acidity of the diesel engine. They have been in business for 100 years... again I bow to their superior knowledge !

Their oil can be, and has been, used to extend the service periods for oil changes to twice the normal mileage. A car running on their oil products did 250,000 miles. It was stripped down by an independent lab and declared good for another 250,000. That car had only ever seen oil changes at twice the normal interval so I guess they know something about diesels. Their oil products are only found in specialist suppliers, normal garages don't stock it.

Andy,
That looks to be an interesting engine with some serious possibilities .[X(]

Will be interesting to see how you get on with it.

Tomorrow could be a flying day, looking at the weather report.
I have made a smaller version of the yeast tin fuel tank so I can easily try some different mixes.
It is a lot easier if I can just take the lid off the fuel tank and tip a different mix of fuel in. I want to try my PAW 2.49, the one with the RC carb so I get chance to see how different fuel blends actually perform when flying.

Reg