40 or 46 Engine?
 

Hi,

I've got a bran new OS 40 that a friend never used but no plane yet. I live in Denver and I've heard that many of the flyers around here fly with a 46 when a 40 is recommended. I'm looking at getting a Kadet LT-40, do you think I should look at a smaller plane with this engine or just get a larger engine for this plane. Or do you think the engine I have should be fine?

Thanks,

Mike

RE: 40 or 46 Engine?
 

I think you will be fine with that plane and engine combo. Build it light and don't worry about it. That way you save on the engine. It will work fine.

RE: 40 or 46 Engine?
 

You didn't say which OS .40 you have. There is a big difference between a .40 LA and a .40 FX.

If it is a .40 LA at your atlitude you will not be happy with the .40 LA and LT-40 combination. Our club uses LT-40's as trainers with an assortment of OS .40's and .46's and we are at 6000'. The .40 LA trainers fly but not well. The .40 FX trainer is passable. The trainers with the .46 FX are really the best. Stay with the LT-40 but get yourself a .46 if you can.

RE: 40 or 46 Engine?
 

Why not just look at a smaller plane? A Tower Trainer .40 kit is $45.00. That engine would probably pull that airplane around pretty well. You could also put it on an LT25. I watched a guy fly one with a .40 on it yesterday and it seemed to fly fine. My LT40 is almost done and it is a big plane. I'm putting a .46 on it. Not that I'm an expert but I think I'll be glad for the extra ponies in this plane.

RE: 40 or 46 Engine?
 

I built the Lt40 from kit and flew it with the .46Fx no problem, then tried the .32 Fabc OS and it again flew very well. The .32 and 40 LA are about same in power, however the elevation here approaches nose bleed country at about 300 feet msl. Use a much lower pitch prop, like 10 by 4 or 11 by 4, and you should have a ball.

RE: 40 or 46 Engine?
 

The engine reads: OS 40 FP but I can't find any other markings. I assume this was the older version of the FX?

Thanks for everyone's replies!

Mike

RE: 40 or 46 Engine?
 

Actually that is the precursor to the LA. Much less plastic and better looking in my opinion.

RE: 40 or 46 Engine?
 

the 40FP was a great engine, not super powerfull but reliable as they come, all things being equal it should fly most of the 40 size trainers fine.

RE: 40 or 46 Engine?
 

O.S. FP .40 + any .40 trainer = plenty of power!

Jetts

RE: 40 or 46 Engine?
 

Usually, yes. I don't know how well it will work at your altitude though.

I would get the LT40, and plan on the possibility of an engine upgrade (You'll want to do it eventually anyway)

RE: 40 or 46 Engine?
 

I second getting the LT 40 and considering a future engine upgrade. I started out with an LT 40 that had one of the old K&B 40's. It had less power than a os40la. I was fine with that combo. I live in Minneapolis, and elevation is not a problem. Once I became comfortable with the plane, I installed a MDS 48 ball bearing engine and it was like an upgraded plane.