OS LA46 Question

I am considering an OS 46 for a Road Runner. I don't know anything about this engine but the price looks inviting, can anyone give me some input. I would also like to know if the plastic backplate can be replaced with metal. also how much of a problem is it to replace the rear mounted needle valve assembly with a conventional type.

I run the LA 46 as do several advanced and expert flyers at NVCL in Virginia. I think there are 5 of us using them almost every weekend.

We all went to front needle valve for a more reliable cutoff at end of flight. I fly a 12-4 on mine, one guy uses a 12-6 and I think the others are flying an 11-5 and an 11-6.

We all run 5% fuel with 22% oil (11% castor).

I think we all still have stock plastic back plates even though many on this forum advise switching to metal.

These are very nice stunt engines in a cardinal profile and similar sized ships.

L.L.

Go Ahead and purchase a OS46LA it is a great engine right out of the box, plus it is lighter than most 40's. I got one and I love it.

L.L.
The backplate can be replaced with a Tower or OS 40 backplate, IF it is giving you problems. Mine has not been a problem and the engine is 6 months old. However do away with the rear needle valve it will in some piping configurations, give you problems. You can purchase a OS replacement for a 40 size engine and yes it is the same one.

Add a tongue muffler.

Best bang for the buck. Get the control line version that has the venturi. Hacksaw the remote NVA off the plastic back plate and keep the screws tight. I suggest getting a PA (Nelson) NVA to use with the OEM venturi. You'll need a tongue muffler because, the stock muffler weights 3 ounces.

I like the .46LA very much, but it's really big and heavy for a Roadrunner. I am a believer in replacing the backplate, NVA and screws. Otherwise, it's great. But...

A Rustler Merco "Morph" .40 (from RSM), a Brodak .40, a Randy Aero "Aero Tiger .36" or RO-Jett Magnum .36 would be more suitable, from a size and weight standpoint. There are two other threads on the Roadrunner, currently well down on page 2 of the forum. You might find some useful info there, or at least some cool color schemes. Steve

I'd go with the OS 46 LA for the Road Runner. It is THE best motor for the money available!! We have run several of these with great success. I put in a standard NVA (OS or ST, it doesn't matter), use a tube muffler from Randy Smith or Richard Oliver (with pressure) and the APC 12.25 x 3.75 CL prop, cut down to 11.75. That setup always works beautifully.

The 46 LA will provide much more power than the Rustler 40 or Brodak 40.

The OS .4/46 LA-s is a great engine for PA. Just toss the rear mounted needle and instal a ST version in the venturi. You may have to drill the hole slightl larger, I did. Also I changed the rear plastic backplate on all of mine due to one of them leaking quite noticeably. The OS .35,.40 FP back plates are the same, except for being metal.. Also the Tower .35/.40 rear cover is the same, ceptin the arrow.

Yes, that arrow on the Tower backplate has come in very handy. I install it with the arrow pointing "up". That way I always know where to find the glow plug. LOL

Seriously, it's a good engine for the price. But do chuck that rear needle valve and change the backplate. You'll save yourself some aggravation later.

Cheers,

Ron King

> But do chuck that rear needle valve and change the backplate. You'll save yourself some aggravation later.

Or buy the RC version and sell the remote needle/carb on the bay for a nice price. More than enough to get a proper venturi and needle valve assembly.

>Or buy the RC version and sell the remote needle/carb on the
>bay for a nice price.

Buy the RC version and you can also get it in natural aluminum finish - unless you are particularly partial to blue.