RVator

My Feedback: (1)

I put an OS 46LA on my stick 40 trainer. My instructor and others recommended a plain bushing engine to start with. So far it has run great with a nice reliable low idle. I am on my third gallon of fuel and it needs very little adjustment and starts good. I know there are more powerful 40 size engines around and I plan to get a TT 46 pro for the Spadstick I am building but the LA has done what I wanted,provide reliable power for training.

Avistar23

IMO thats what it was designed for.... i had one in my trainer... it did its job well... Ive had 3 LA's, one had probs one hasn't run yet and one is still good... but i have a FP probably twice the age of the LA and it runs better than it... and the LAes is in no way comparable to the FXes... but i don't think that was the point of that line ... IMO it was made for a trainer and not to be to powerful and have a good price all at the same time..

downunder-RCU

Although this is an entirely different application the 40 and 46 LA's are getting an extremely good reputation when used in CL stunt to the point where they're now being compared to the venerable Super Tigre 46. They're light weight, swing a big prop, start easily at full throttle (by hand of course ) and are very long lasting. Of course, they're not run on normal RC fuels either.......

Dave Bowles

My Feedback: (7)

What killed the LA series engine was the .46. although it can be reliable engine, it simply lacked the power that most people "EXPECTED" from a .46. part of this was because some were trying to run it at high RPM, when it is not ported for it, Some did not give it enough break-in time, I found using larger props like 11-6 and 12-6 worked much better than 10X6 and 7s . MANY of the LA .46 engines had problems with the remote needle leaking as well as back plates leaking (I had this problem myself on several .46s) . Because of the expectations of the .46 it was purchased more so over the .40 , so you can expect a higher number of problems. IMO "The step back" was in the Plastic Back Plate and remote needle carb , I also read somewhere here at RCU but have not verified that The LA liners are thinner, don't know if this is good or bad. With the FPs you would sometimes break the needle and spray bar in small crash, it could be replaced easiely in most cases, I even soldered many back together, whe the plastic remote breaks it sometimes breaks the backplate as well, the engine must be removed to repair, the plastic backplates bolt lugs will eventually come loose , you can only tighten them so much, even with lock-tight the plastic will eventually give and leak. O.S did not make a .46 fp so you can't compare them, but the last Generation of FP 40s (and tower .40s) turned the 10X6 props just about as well as the .46 LA did (but not bigger props). I have ran the .25 L.A. and the .25FP and it runs about the same but the L.A. is still a cheaper built engine, I would not say it is CRAP, but I do not like the plastic parts. IMO the LAs were a Slight Step Back , The FP series worked , there was nothing wrong with it, there was no reason to change it, and IMO the LAs are not as good an engine as some of its competitor engines like the TT GP 25 and 42. In both performance and quality. I really don't give a rats tail about the looks of an engine, but if it works, don't fix it.

Cyclic Hardover

My Feedback: (3)

Also for the cost of an .40 LA, you can get a TT46pro which is equal in power and performance to the 46fx

bipeflyr

My Feedback: (2)

I built a light 4 star just for an extra LA46 I had around. The plane weigh's 4 LB's total and will hover, hand starts on first try and is a very reliable motor, just stock including the baffle, a dubro exaust deflector and APC 11X5. I dont think you could buy a better "bushing" motor. Only trouble is that there arent many "light" 40 sized planes around, the motor is best suited for a trainer or other 40 sized with light wing loading.

f2racer

For any fans of the OS 40 or 46 LA, check out the TT GP-42. It's an el cheapo brushing engine too, but is MUCH nicer than the OS IMHO... Makes more power than either the 40 or 46.

Jim C.

I AGREE!! very good motor.. i love mine.. i wish i had a funfly plane to put it in.. if i ever finish my pbf, i think that is the motor im gonna put in it

canadianjosh

I like my OS .40 LA, runs like a charm. In fact, when i first pulled it out of the box, and fueled her up and tryed starting her, it fired on the first flip and scared me making me drop my stick into the prop which quickly stalled the engine and ruined a prop. Now 4 years later, my engine still runs strong and halus a lot of ass. I have had to do few repairs to this thing, only change the plug twice, replace the head once because i stripped the threads out, other than that, just clean it out each season. This is the engine that i have used to run many experiments for alternate fuels, and for performance inhancers. A few of these have been direct oxygen injection into the carb, direct nitrous oxide into the carb, running hybrid fuels of glow/gas, glow/naptha. None of these would be practicle of course, but neat to push the engine a little, i don't think OS ever designed this thing with 21,000+ rpm in mind while spinning an 11x7 prop. It is a nice little gem for under 100 bucks

Rudeboy

Say Josh...

Now I'm curious: which of the stated experiments to increase the power output of your LA .40 brought it to spinning a 11x7 at 21000?

foxx

My Feedback: (2)

The best way I found out to increase the power of LA .40 was to replace it with a OS FX series.

canadianjosh

fox has got a good solution to increase the power, but what i did was run it on 45% nitro fuel by volume, and with the nitrous oxide injection, burned 8oz of fuel in about 4 mins, the 45% by itself bumps up the rpm by about 1400 rpm, from running 5% normally. What i did was open the needle valve around i think it was about 4 turns from the normal peak rpm setting, and then fog the NO2 into the carb. As you would guess this would generate a lot of heat, and it did, ahaa, thanks for the advent of water cooling, hooked up to the house tap. Scary but cool! All of the equipment to do this weighs about 20 lbs, so it would never make it into a model plane.

foxx

My Feedback: (2)

Josh did you use the tap water for water injection or just cooling, . Thanks

William Robison

My Feedback: (3)

Josh:

Having been heavily involved in the faster classes of drag racing, including multi-stage nitrous systems, I just can't see that LA staying together long enough to need any extra cooling.

With three stages of nitrous oxide I've been able to get more than 6000 hp from a 500 ci concrete engine, but never more than a second without the engine blowing up. The third stage is just for that last bit, in the last fraction of a second, before the traps. And the engine gets a major overhaul after that fraction of a second.

Your LA, at 21K rpm with the 11x7 seems to me to be also in the one to two second engine life class.

How long did yours last before the piston, rod, and crankshaft went their separate ways?

Bill.

canadianjosh

Foxx: first of all i never did any water injection, the cooling that i used for my engine during all testing was ciled copper tubing around the head, and exhaust port, with heat sink paste underneath for maximum heat transfer. I simply hooked this up to the tap for a cool high pressure water source.
Will: Your right, my engine ran for a total of about 10secs with the NO2 fogging before the plug blew. When i richened up the fuel mix, the rpm dropped to around 8900rpm, then i started fogging, i had tested earlier with small amounts and different feed rates, this test was to see how much i could give it. I was actually surprised that nothing else happened, i was expectiing something to go, most likely the connecting rod, but it didn't, instead the plug filiment melted. I have a lot of experience with high horsepower applications, allthough nothing over 1000 hp. 6000hp is simply amazing, i helped my friend build up a 454 big block for his '68 supernova, it's now bored out to 461ci (7.4L) and makes 640hp at the wheels. If you don't believe me about the NO2 in the engine give it a go yourself.

foxx

My Feedback: (2)

Sorry Josh for moment I thought you were kidding about putting that little poor LA through that kind of torture. You really must have hatted this engine trying to get 600 hp out of it.

canadianjosh

I didn't ry and get 640 out of the OS 40LA, i don;t know what it makes but my guess is it probably makes around 2-2.5 hp at 21k rpm. The big block is for a full size car, i spoke with my buddy and he said that unless you were running a top fueler drag car you'd never see 6000 hp in a 500ci with just NO2. By the way, what the heck is a concrete engine?? Top fuelers are limited to 500ci, and run on straight nitromethane making in the range of 7500hp for about 6 secs until kaboom, something blows.

canadianjosh

The supernova is really really fast, that's all i can say, will run mid 9's for a 1/4, pretty quick for a street legal car. Very loud, and will eat any import rice rocket for breakfast.

Rudeboy

Sure mid 9's is pretty fast... but 640 hp at the wheels out of a 7.4 litre displacement engine is still pretty modest IMO...

It may eat those imported rice rockets for breakfast, but these guys are running only 1/4 or 1/3 of the dispacement, and still giving you a hard time

Don't get me wrong, I like big V8 engines too, but 640 hp out of 7.4 litres compared to lets say 300 hp out of 2 litres is a big difference...

William Robison

My Feedback: (3)

Josh:

A "Concrete" engine is one that has all the water jackets in the block filled, or a special block cast with no water jackets. In either case the cooling water goes through the heads only. And the water pump is electric, not driven by the engine.

My "Big" engine was a concrete 577, four two barrel carbs on a log, the nitrous was 16 injectors in the inlet stubs, eight each for the first and second stages, and eight more, one in each carb barrel for the third stage. A total of 24 nitrous/fuel nozzles. The engine was fed from two fuel cells, with two high volume high pressure electric fuel pumps. One for the carbs, the other for the nitrous mixers. The longest I got it to run on a dyno at full power was less than one second before something broke. At 4000hp I could run it as long as 15 seconds. Not a street engine. And the 6000hp is an estimate, wouldn't run long enough to get a stable reading. But at 190-200 mph it would give a healthy additional boot in the butt when you hit the 3rd stage. ET's running 6.1 to 6.3 seconds, trap speed 210-220 mph.

My street car is a piddly little 305, dyno'd at 430hp. Gets me where I want to go.

Back to R/C, please.

Bill.

tiggerinmk

I've got 4 LA engines, does that qualify me?

My 1st engine when I re-entered R/C a couple of years ago was an OS 65LA which I put in a Superstar 60 (correct application I think ).
I was sold a gallon of green Coolpower to go with it. 1st big mistake I think...
2nd mistake: The Superstar (along with lot of other ARF's probably) has a former shaped to firmly hold the fuel tank. Result: vibration from the engine is transferred directly to the tank.
This in combination with the wrong type of fuel (which other club members denied) did not get the engine off to a good start.
It took me over a year to finally get that engine running right (OK so I didn't fly much) then I put the plane through a tree.

The engine was transferred to a Hobbistar 60. 1st flight with an instructor went fine (fuel was Byron 15% semi synth). A couple of months later I got back to this plane and flew it myself (for about 30 seconds). I happened to be using Omega 5% fuel, the plane seemed to take off ok, but quickly lost altitude after the first turn. When I get around to digging all the mud out of the engine you can bet I'll thoroughly test that engine before putting it in another plane. I doubt if I'll ever fully trust it...

2nd engine is a .25LA which I put in a Sturdy Birdy. The engine ran great straight out of the box. It might not be quite enough engine for that plane but it survived the rigors of being strapped to the front of a drainpipe.

3rd engine is a .15LA which I put in a Ripmax Zephyr. Again ran great straight out of the box. This engine is more than adequate for the plane. Get lots of deadstick though, I think that chugging around at just over idle for about 10 mins causes it to load up. When allowed to rev up (on hand launch) it goes very well..

4th engine is a 46LA. Got this as a substitute for the 25 for the Sturdy Birdy. Not installed it in a plane yet but have bench run it.
I've had around 11000rpm out of it on an 11x6 and 12000rpm out of it on a 10x6 APC prop. I was testing it against an Irvine .39. The Irvine gets up to 13,600 on the 10x6 but then its a quality BB engine...

All in all, despite my initial experience, the LA's are pretty good for what they are: a cheap sports engine. Why have I got so many? 'Cos that's all my LHS's sell. These have been bought because I needed an engine quickly and the LHS has the same price as Tower.
I think that the LA's sometimes get a bad rap because its mostly the newcomer going to the LHS that buys them. Then they get broken in and run incorrectly due to lack of experience and then people complain when they don't perform as expected.

Spaceclam

nobody at my field has an la engine. they all say, for your money, the fx is a better engine. NO deadsticks, TONS of power, can handle higher nitro contents and just runs better altogether. i will never to back to those. in my opinion, they belong in edgers, not planes

tiggerinmk

Maybe you're lucky enough to have an LHS that offers a choice of manufacturers for 2 stroke engines. I had a choice of OS LA or MDS, some choice eh?

Now I have have mostly all of the LA's (except the 40) I don't feel the need to get another one. I don't particularly feel the need to buy an FX either.

Looking at my options what have I got to choose from? Half a dozen Chinese brands, or maybe Taiwanese or Japanese.... Not very inspiring....

I think my next engine will be either an Irvine .53 or .72....

William Robison

My Feedback: (3)

Tigger:
If I had that choice I would without hesitation take the MDS.

MDS has given me excellent service.

Perhaps, had I stuck with the only LA I've had i could possibly have liked it.

But the Butt-Ugly "Duck-Tail" cylinder shape, the sickly blue color (all that was available), combined with cruddy oeration?

I just kissed the money goodbye and tossed the POS LA in the trash.

Bill.

tiggerinmk

Bill, I've read your comments before on the MDS engines, I'm glad you've had a good experience with them. It seems that both MDS and the OS LA series provoke strong arguments with many users.
I've not owned a MDS so I won't comment either way on that, but I think the LHS (local to me) that did sell them is going to stop based on comments from customers.

I could have quite justifiably thrown my engine in the trash and not bought another LA based on my experience with the 65. But I didn't, I perseveared with it and have been pleased with the other LA's that I have.

In future, I will try to buy what I believe are 'quality' engines. This leaves both the LA and the MDS out of the scope (no favoritism).
Hence my next choice of Irvine...