750 SF2 Mondial pistons

TeddyG said:
Thanks Redax and Rez,

Since the Ross forged expand a bit more than cast, I was wondering if .003” is a bit too tight, and I,ve considered checking the oil pump. I’ve also been advised to get the skirts Teflon coated.
Regarding oil, SpeedDiagnostics who analyzed the 1300 mile mineral oil said it had lost viscosity and has a lower shear stability, so perhaps this is due to some other factors causing this.
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I should think that any oil having spent 1300 miles in an aircooled full roller bearing engine, without an oil filter and sharing the engine with the gearbox, not to mention two big chains flapping around would show at least what your oil analyst found.
Paul
 
Paul Marx said:
I should think that any oil having spent 1300 miles in an aircooled full roller bearing engine, without an oil filter and sharing the engine with the gearbox, not to mention two big chains flapping around would show at least what your oil analyst found.
Paul
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Probably a point worth taking into consideration - ie, unless you have a 'test' reference of oil from an equivalent motor after 1300 miles that's running without problems, then 'loss of viscosity' isn't a viable indicator.
 
I could re-use the Mondials but the re- bore is now too large and the top ring grooves are beyond spec. Wolfgang doesn’t seem too keen on sending parts domestically, and I’ve contacted Ross several times but they are moving. So I have a nice garage ornament!
 
TeddyG said:
I could re-use the Mondials but the re- bore is now too large and the top ring grooves are beyond spec. Wolfgang doesn’t seem too keen on sending parts domestically, and I’ve contacted Ross several times but they are moving. So I have a nice garage ornament!
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I could supply you with a stock bore cylinder barrel...
 
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