darrzemp

Anyone out there. What is the 2Cycle equivalent of a Saito FA-.80 4 cycle engine? Thanks for any reply.
Darryl Zempel

daveopam

My Feedback: (9)

That's hard because they are so different. A good .60 2 stroke makes about the same power. But to swing the same prop would take a 90. Saito 82 I swung a 15x4W. OS 90 I swung a 13x8 or 14x6. A 20cc gas is another good alternate.

David

darrzemp

David- Thanks for the reply. I have found the manual for the FA-.80 and Sport flying Prop suggestion is: 12x6, 13x6, 13x8 & 14x6. This is what I do. Just my thoughts, Seems like this 4 Cycle would be close to a OS .65 or maybe even a .61. I would have hoped a little closer to a .55, but that seems to be out of the question.

Thanks again for your reply. Sincerely Darryl.

Anyone else have an suggestion?

rgburrill

Technically a FA 80 is a 2 cycle engine, not a 4 cycle. It is a 4 stroke engine.

Also, as pointed out above equating 2 stroke and 4 stroke engines does not usually mean using the same props but rather providing the same thrust. Larger volume 4 stroke engines typically turn larger diameter props, or more blades, at a lower RPM. People like them because they "sound more realistic". But do they really? A P-51 Rolls-Merlin V12 turns between 2400 to 3000 RPM. With 6 cylinders firing every revolution that's equivalent to a single cylinder turning 14400 to 18000 RPM. Have you ever seen an FA-82 turn more than 12000 RPM? A decent 60 can turn 16000 to 17000 RPM. I had an OS32SX with a 10x4, 3-bladed prop on a Royal Midi Corsair. It turned 19000 PRM and had more thrust than a 10x6 driven by a Tower 40. But even at 19000 RPM it didn't have the same high pitched scream that the Double Wasp radial Corsairs had.