checking the longstroke crank of the M244 quattrini. centering: 0,01mm, stumps: 0,03 and 0,04mm (the cheap mazzuchelli has 0,01mm btw...) but both cheeks diameter are not regular, there is a bump of 0,06mm in the area of the crank pin / balancing bores.

as we need 0,05mm rotary valve tolerance that the valve works 100% this crank is NOT USAABLE out of the box for rotary valve. for a price of 412,- thats a pretty bad joke.

reed valve no worries all fine.

so u need to machine the rv cheek. thinking of the rotary valve target measurment 0,05mm this means: a) the rv cheek will stripe at the rv pad of the engine case or b) u will have blowback problems as your rv will be at least 0,11mm instead of 0,05. (si24 is more sensitive than bigger carbs with manifold).

"high end tuning parts" approach? a simple mazzuchelli crank for 130,- does better with all crank factors.

defect&solution: work on the cheeks and get rid of the bump. alternative would be to take another crank ie kingwelle.

kingwelle good2know: cool name indeed, but pls also check it in detail, i checked 2 cranks, both not propiate for tuning, way cheaper mazzucchellli also do better.

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