earl williams

My Feedback: (27)

I have an apc 16.5x5W on a fusion 3d plane turning 10,000rpm. the engine is cool and spools up real nice out of hovers.

Is the rpm too highj for this engine? I also use an APC 17x6 at 9000 rpm, but the engine does not spool up as quickly. Ingine temp is jujst a little warmer, but not hot.

What is your advice?

Troy Newman

The Rev Earl Williams,

How are you my friend?

For 3D the 10k is OK just don't run it there for really long periods of time. It will be fine I just would not run the engine at Full power for a full flight.

The simple fact that the engine is lightly loaded and spools up quickly is good for the engine.

Troy Newman
Team YS

earl williams

My Feedback: (27)

Thanks Troy, hope you are well. I am doing fine. Thanks for helping us out on this forum, it is very much appreciated.

Earl Williams

stickman/vic

My Feedback: (85)

What if I wanted to develop the most power at the lowest RPM, what prop would be best and what would be the expected RPM with 20/20? Vic Koenig

Troy Newman

There are too many variables to answer this question on a specific prop. The model you are putting it in will play a huge role in the best power at the lowest rpms.

I would say don't run the engine below 9000 rpm for a YS110. To get this rpm on a 20/20 fuel will depend a great deal on the fuel, the air temps, the elevation, and humidity levels. I can't give you one answer as there is not one magic answer.

prop choice are like gear choices in a car transmission. The prop you choose can be for max speed, or maximum acceleration. In general the lower the prop pitch the better accelerationa nd the lower the top speed. The higher the prop pitch number the better the top end speed but the lower acceleration.

Some good choices of prop will be 15-8 to 15-10 APC,

a 16-6 to a 16-8 APC, for slowerapplications


the 14-12 to 14-13 would be good for speed

The engine is running between 9000-9500rpm it is making its best HP numbers. So choose a prop that hits these rpms.

A wide body model will like a larger diameter prop, while a narrow fuse would probably do better on a smaller diameter. There is just too much to affect the result for you max power output. A heavy model will liek the higher pitch props as they can maintain the speed better, while a a lighter 3D style model will like a bigger diameter lower pitch prop as the acceleration is much better.

Troy Newman
Team YS

stickman/vic

My Feedback: (85)

I have tried a 15/10 and it seems to sag a little in the verticals. A 14/12 was best all around (9.3-9,5 static) but I just got an APC 15/8 today from Central. I'll give it a try in the air. The plane is a David Hoppes FAI (not 2 M) "Persuasion", an older plane but I've put wider wings on with 200 more inches that are very thin so it's really a joy to fly.
Thanks for the help, thought there was some secret I was unaware of ans I figure the engine guy would be the one to ask. Vic Koenig

Troy Newman

Actually I'm more aof a pattern flyer than an engine guy....But don't tell anyone in this forum.


The 14-12 is a good option for a pattern application.

If you want the 15-10 to be better add some nitro. The 30% Cool Power Heli fuel will make the 15-10 a really good combo.


Troy Newman
Team YS