RC-Lew

Hi

What's the difference between the FX and LA models of the OS 46 (besides price ??? I see that one comes in two different colors, but what else is different?

Thanks for your help!

Mettler1

FX has ball bearings and a real carb! LA has no ball bearings and a dinky carb.

FX makes horsepower and the LA is a slug.

Problem I see with the LA is flyers are always trying to get more power out of them so they keep leaning them out and end up ruining them. Look and see how many post there are on RCU asking , "How do I get more power out of my LA?"

Get a 46fx. A great engine!!

Homebrewer

My Feedback: (8)

The difference is night and day.

FX: Ball bearing supported crank shaft instead of power robbing bronze bushings on LA
More power!
Twin needle carb for more precision in engine tuning.

LA: Economy engine
Not very powerful because of bushing and restrictive carb throat and engine porting.
Cheap and atypical quality from OS.

If you wish to get a great running engine but don't want to spend the money for an OS FX but like the LA .46 price then you may want to purchase one of these other brand engines;

Thunder Tiger .46 about 79 bucks new
GMS .47 50-70 bucks new (20 bucks off with tradein on mecoa website)
Tower .46 (same engine as GMS .47, different brand name)
Magnum .46 Great engine

RC-Lew

Thanks for answering my question and the "similar engines" advice

Tax return = new plane

NebulaDDS

nm

downunder-RCU

First up I'll say I don't have either of them so I'm not biased either way. The difference is that they're designed for different purposes and each has their own advantages. The LA is a beginner or sport engine where the FX is more of a high performance engine. Generally this means that the LA will swing a big prop about as well as the FX but for speed freaks the FX is the choice.

The FX crankshaft needs ball races because it has a much larger gas passage which means a much larger diameter crankshaft. Combine this with the higher revs it needs to get max HP and the surface speed of the crankshaft is too high for a plain bearing. At the lower surface speed of the LA crankshaft the plain bearing is more than adequate and has the added benefit that there's nothing to rust and will last a lifetime given the correct lubrication. Also a plain bearing doesn't noticeably rob power at the revs it's intended to run at otherwise the front of the crankcase would get hot from friction, but it doesn't.

The LA carb is simpler than the FX and while it may not be as precise it's more than adequate for the job and easier to adjust.

Just because both engines are OS is no reason to slag the one that's got less power, they're designed for different purposes. I could ask why anyone would even consider buying a wimpy FX when there are engines like Rossi, Irvine, Webra, MVVS, Jett and Nelson out there

Epoxy Cup

I have two .46FX and a .46LA. They all run great. But as stated they are differant engines. The LA is OK if you understand the limitations and just want some mild flying around. They really are reliable and smooth. If this is your first or only engine and you are going to perhaps put it in something a little faster eventually you might consider the TT .46 or even the magnum there very good also and about the same $ as the LA. I dont think you could go wrong with any of these.

JPMacG

My Feedback: (2)

Keep in mind that the FX weighs a bunch more than the LA. Depending upon your applicaiton, you may not want the extra weight.

I have both and they both run well. FX is definitely more powerful.

Richardfast

My Feedback: (15)

Explain why an OS65LA ($105) makes better power than an OS61FX ($150), as shown in the the "best 10 .60 size engines" test report in the latest Model Airplane News magazine. Don't make assumptions about an engine unless you actually test it.

Flyfalcons

Well, the 65 LA is different than the 46LA, so it's tough to compare what power they make versus their FX equivalents. I just started running a 65LA and I am very happy with it. A 61FX fully broken in might make more power but for the same price as the 46FX, the 65LA is a great engine.

Coleon

Well Said Bro....

Well Said.. And Thank You....

1200SportsterRider

If two engines are identical other than the bearings there will be no difference in power, the difference between the LA 46 and the FX is due to the conservative port timing of the LA. The LA 46 is a fine engine. I still fly an LA 25 on a Sig LT 25 with a nose gear.

1QwkSport2.5r

This is almost a record! This thread’s last response was 21 years ago.

Jesse Open

Had to know that was coming.

Coleon

Gotta Keep Bump'n The Good Ones....