I am thinking of trying pattern. I am used to 2 cycle engines but I also want enough power to get through routines. What is best for a starter who is thinking of growth - here are some engines I've been looking at: OS120 AX, OS 160 FX, OS 140 with pump, OS FS 110a, or other OS ? Do I need a pump?

OS FS 91 Surpass II w/pump

What airframe are you intending to use? That should narrow down the choices somewhat.

+1, it is totally dependent on the airframe. Enough power also depends on what class you will be competing in. The lower classes need significantly less power than FAI.

Mark

CA Epsilon 120 on the building table. Sportsman class, but was hoping to purchase an engine that would get me through this and beyond

If you haven't chosen a plane and want to test the waters without spending a bunch the Venus II and the AX 1.20 is a popular combo.

The .91 Surpass is popular with the SPA crowd flying 1970's designs.

David

I would pick the YS 1.10S, and I just happen to have one that is going in the market place tonight. Going all gas.

The advatage of using a pump is that you can place your tank at or near the aircraft CG and fuel feed to the engine will still be constant despite the attitude of your plane.

There is a pattern forum, and some great info there.

That aircraft, at a rough guess will probably weigh at least 10-11 lb and will most likely need an engine weighing 32 - 36 oz to balance. That pretty much removes all choices you are considering except the OS 1.60 FX and 1.40 RX.

FWIW, in this part of the world at least, guys are typically using the OS 1.40 RX with a pipe or the YS 1.6 or 1.7 for 2 metre competition.

This may be another engine worth considering, if you'd like to go down the OS path...

http://www3.towerhobbies.com/cgi-bin...&I=LXUYX4&P=SM

In the Northeast division (D1), most of the guys are flying OS 160 two strokes on their full 2M planes. Those of us with smaller planes have the 120AX. For four stroke, YS 170DZ on full 2M planes, and YS 110FZ on smaller planes. Then there's electric...

I've got the Venus II with 120AX. Nice intro plane, but you can get nicer planes if you want. The engine is powerhouse for 90-120 size planes. Has lots of low end grunt for a two stroke, but not like a YS 110.

OS FSa110 is not enough power and is heavy. I haven't seen anyone use the 140 yet; seems like a waste of $$$ when the 160 is dominating the scene.

YS engines have a built in pump/pressurized system. Those of us with OS two strokes are using the Perry VP30 regulator.

It really comes down to those 4 engines, at least around here (2 stroke: OS 120, 160; 4 stroke: YS 110, 170). If you are up to getting a YS, I'd say that's the way to go. More stuff to deal with and required high nitro AND high oil fuel (20/20 or 30/20) but the power and sound is unbelievable. OS is easy; 15%, fuel up and fly.

This wouuld be perfect for you. But the sound, throttle responce and transition are from a YS, and YS only.
http://www.rcuniverse.com/market/item.cfm?itemID=463911

I am using a OS 140RX. and have ran this engine in intermediate, advanced and now Masters. A very trouble free set up.

A couple things to remember a 140RX is a rear exhaust and will need a header and a pipe.

A 160FX can use a stock muffler big and ugly or a pitts style muffler. The engine will really wake up with a header and pipe. Along with a Perry pump.

A 170DZ will aso need a header and a pipe.
PM if you want to talk. And curious where do you fly at.

Dennis

Argh, I wish this ad came up one month from now when I had the money for it[:@] And another[:@] 'cause I really want it[&o]

Good choice in models. I have the 60/90 sized one with a Saito 1.25 on it.

Daniel,


As others wrote, the need for a fuel pump is dependent on the plane you select, on the engine and on the placement of the fuel tank (if you have a choice).

If you stay with glow engines and choose a YS, you wouldn't need a fuel-pump. The same goes for pumped engines as such.


If the engine is not pumped and the fuel-tank is right behind the firewall, you might get away with not getting a pump, although large tanks and large engines tend to suffer, from attitude change induced fuel-pressure changes; compared to small engines and tanks.

If you locate the fuel tank on the C/G, there's no question about it... You will need a fuel-pump and regulator, even if you would just be 'ironing the surface of the sky'...