Hi again all engine tinkerers..!
I think I owe you all an update on how my modded engines do perform:
Finally last summer I took six Saito engines and placed them in my test stand using the same reference propeller (Ishipla 11 x 7½), same fuel 12% synthetic + 6% castor + 5% nitro, the same brand new OS F plug and attached you will see the results.

Special notes:
1)I chose to run all engines on 5% nitro as a compromise to have them all run acceptably well.

2)Overall it seems that milling the crankcase does not increase power much but the engine certainly runs better on 0% nitro which was my goal from the outset.

3)The .50 GK(HB) engine fitted with the longer conrod is so far a failure but I do NOT know why.

4)The .56 (LJ) engine with the “swiss-cheesed” piston is still running strong after 5 seasons use in my Sig Cougar airplane. This is a pleasant surprise to myself and probably some of you too…=)..! Admittedly it does spit out more oil from the crankcase nipple than normal and it has developed a slight bearing noise so I guess it is a bit “over the hill” by now. Will dismantle soon.

5)I cannot explain why the .56(AL) engine has a CR of 10.7 after only 1.0mm milling but that is the case after two separate measurements.

The Enya.60 engine (post # 19) was also tested here but that is another story to be told later…Cheers/Harald