ORIGINAL: JariV
By the way, how would you chacterize the differences between Saito and OS? You prefer Saito clearly. I would like to know your insight to your preference. I am curious.
I have (had) Saito, OS, Webra, Laser and few other brand of engines. And gasoline engines too but somehow I like nitro more with airplanes. Regarding rc-cars its gasoline all the way.
I have nothing bad to say about O.S. engines. My limited experience W/them has shown me very good build quality power & reliability.
My preference for Saito engines is due to the 1 piece head/cylinder arrangement that allows optimal port routing & the pent roof (Hemi) combustion chamber also allows larger valves/ports that allow optimal breathing in the RPM ranges we use.
Almost all aircraft & 4-stroke motorcycle engines are of the "Hemi" design, some of the former utilizing the same 1 piece head/cylinder configuration.
The simpler straight gear cam drive of the Saito singles also has (slightly) less parisitic power loose than the helical Surpass cam drive.
The only bad experience I had W/Saito was an exhaust valve sticking problem most likely due to the castor content of the Byron's 4-stroke fuel I used when I started R/C flying W/my 1st FA150. It wiped off part of the exhaust cam lobe. The engine ran OK albeit there were some issues W/reliable idle which eventually lead me through onboard glow to electronic ignition in the search for the lowest reliable idle. In the end that was a very fortunate experience.
I dscovered the cam issue when I had to dismantle the engine after a full throttle, straight-in re-kitting of my Sr Telemaster ARF when I misjudged altitude right before initiating a split "S". Horizon sent me a replacement cam W/nothing more than a phone call, so that initial negative experience was not so bad in the end.
I have since run full synthetic 15% Morgan's Cool Power for both glow ignition & spark in all of my Sato engines W/O any more reliability/durability issues.
The new O.S. "V" series engines are interesting as they seem to be utilizing some of Saito's design features. The 420 7-cylinder radial looks awesome, but the price is just not justifiable for the size aircraft that would utilize that power level. It's as much as some of the medium sized Moki radials of much larger displacement. Too bad as W/it's 230mm diameter, it would be an excellent choice for the 80" WS Hughes H-1 Racer.