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04-29-2015 11:29 AM

TomGSMackay

You can't go wrong with a Saito 82 or 91 in a 60-size trainer. Not experienced with the ASP's, but OS and Saito have both been good to me.
Save the 120 for another airplane. In trainers, as in all airplanes, lighter planes simply fly better.

04-17-2015 11:27 PM

OLD PRAIRIE RED NECK

Re: 90 or 120 engine for my first planes?

Quote:

Originally Posted by Nazair

Thanks for the suggestion. I looked at the Saito prop size page and no 5" pitch prop is recommended for the 91, would you have a suggestion?

True, the 14 x 6 is the lowest pitch they list. Normally if you go down one inch on pitch you need to go up one inch on diameter to keep the engine in the same RPM range. That would make it a 15 x 5 prop. I suspect ground clearance problems with that diameter and trike gear. You may get away with a 14 x 5 prop if you watch that the engine RPMs don't exceed the manufacturer's specs. A 3 blade prop may work in a smaller diameter but I think 6" pitch is the lowest I have seen.

I am running an APC 14 x 4 wide on an OS .90 4 stroke but it puts out much less power than a Saito.

04-17-2015 09:54 PM

williame3590

Re: 90 or 120 engine for my first planes?

Good one Ed.

Bill

04-16-2015 03:55 PM

Ed Smith

Re: 90 or 120 engine for my first planes?

Quote:

Surprised about the ASP having an issue but that could have been one of twenty thousand motors or more motors.

ASP stands for "All Sorts of Problems"

Stay with O.S.

Ed S

04-16-2015 12:05 PM

mrrandyman

Re: 90 or 120 engine for my first planes?

I would just stick with the recommended engine for that plane. I like the Saito or OS engines myself.
They last many years if maintained properly.
Just stick to the basics until you've flown the plane to a point of where you want to upgrade to something else.
Trust me you will change your mind a hundred times in one season before deciding on your next project and that big engine you want to buy may not fit the bill for any of them.

04-16-2015 10:39 AM

stegl

Re: 90 or 120 engine for my first planes?

I believe that a 4 stroke needs a higher pitch due to lower max rpm's vs, a 2 stroke as the 2 stroke develops it's max power at a much higher speed. That's another thing I like about Electrics as they develop gobs of torque at any rpm; not just a narrow band at the top end.

04-16-2015 10:10 AM

Nazair

Re: 90 or 120 engine for my first planes?

Quote:

Originally Posted by OLD PRAIRIE RED NECK

Read - low pitch prop. 5" max for a 4 stroke, 4" max for a 2 stroke.

The prop pitch is what dictates the speed the plane travels.

Thanks for the suggestion. I looked at the Saito prop size page and no 5" pitch prop is recommended for the 91, would you have a suggestion?

04-14-2015 10:52 PM

hobbyflyer

Re: 90 or 120 engine for my first planes?

Personally I would use an OS 65 AX 2 stroke for this plane. If this is your first trainer the 65 AX has more than enough power for the plane and can take it to limited vertical. If this is your first glow engine the 65 AX is pretty much hassle free allowing you to focus on learning to fly rather than worrying about tuning the engine. IMO 4 strokes are not suggested for beginners. Have you checked out any videos with this plane flying with a 65AX? It flys quite well.

04-12-2015 10:50 PM

OLD PRAIRIE RED NECK

Re: 90 or 120 engine for my first planes?

Quote:

Originally Posted by Arn

One more thing to think about .... whatever size engine you choose make sure that the prop you use will allow the engine rpm to slow down enough and keep running without providing any significant thrust so that the aircraft can actually lose airspeed.

Read - low pitch prop. 5" max for a 4 stroke, 4" max for a 2 stroke.

The prop pitch is what dictates the speed the plane travels.

04-12-2015 02:32 PM

Nazair

Re: 90 or 120 engine for my first planes?

Quote:

Originally Posted by Arn

That sounds very wise, thanks !

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