Izfisk

Hi I am going to choose engine for my top flite P-47 razorback. The most common engine seems to be the saito 60 r3 but i would rather have the 5 cylinder engine at 73cc.
What do you think? It is not much to read online about it exept specs. is it too heavy for the P-47?

Best regards
/Peter

cathurga

I think it would be a good fit, size wise, but might not produce a noticeable difference in power from the FG60R3, there are two more cylinders so more parasitic drag....but would be a very nice engine to have in there. Be aware that the Saito Radials have some inherent timing problems..and a few other 'quirks'.
I think the FG90 fits in there, if it does, I would go with that rather....

or....

Have a look at the UMS engines, they also have some nice radial options...

Izfisk

I had a look st the 7 cyl usm 90cc not so much more money and the same diameter as the Saito r73.

Tom ling

I believe the UMS 75 is only 5mm bigger but it will run a 24x10 vs a 21x10 lovely engine, I am contemplating one or a saito 60. It’s more money but you don’t have to get the backplate and timing ring fitted to get it running at its peak.

cathurga

I have heard that the 5-cyl UMS engines are the ones to consider. They have been designed from the ground up, as being petrol engines, the others are mostly converted glow designs. Saito are effectively glow engine designs, that are running on petrol. I have not seen a lot of info about the Saito 75, but I think I would prefer a 90 if it would fit.
My next project I am looking at a UMS 90cc 5 cyl....just because it needs to be user tested..!

Tom ling

looking forward to seeing how you get on. 👍