OS .46 AX

[Angelo Smyth]

Does anyone use the OS .46 AX? I have one I was thinking about using. It runs really well, but they seem heavy.

[Tom Vieira]

i have a 46AXII in my gypsy at the moment, you're right, they are heavy.

whether I use it or not will depend on CG after covering......

[Ken Culbertson]

Does anyone use the OS .46 AX? I have one I was thinking about using. It runs really well, but they seem heavy.

I have an 46FX which was replaced by the AX.  It was just too heavy and powerful for the plane I bought it for so I put it on the shelf and replaced it with an 46LA.  The plane with the LA is 52oz and those 4 extra oz in the front of the nose and three more in the tail just to be a bit nose heavy - not good.  The LA gives me 5.5 laps on 65' lines where the FX did it in 4.1 running rich.  If you can get them on a pipe these engines will produce as much poser an a lot of the .60's.  Just make sure you do a really good pull test - then do it again!

My advice - get an LA.

Ken

[Jim Svitko]

Are the OS 46 FX/AX similar to the Magnum/Asp 46?  That is, in regard to weight, power, fuel consumption, run characteristics?

I have an ASP 46 in a 62 ounce plane right now.  I re-worked the mounts of an old plane to get some flight tests on the ASP late last summer.  This old plane had been powered with an LA 46.  The weight of the test plane with the ASP 46, after adding 1.5 ounces of tail weight, was 59 ounces.  The ASP handled that very well and needed only 4.0 - 4.25 ounces of 5/22 fuel.  I did not notice if the added weight adversely affected the plane's performance.  The plane appeared to perform as it did before.  Besides, I was more interested in how the ASP ran.  I did nothing to the ASP but add a venturi and needle assembly from Randy.

The ASP, with no muffler, weighs 11.9 ounces.  The LA 46 (no muffler) is about 9 ounces.

I have a few flights on the new plane.  So far, the ASP is doing very well.  Maybe it will not do so well in hotter weather but we shall see. 

Since the fuel consumption of the ASP is rather low maybe a slightly shorter nose is all that is needed to be able to use these engines.

[Ken Culbertson]

Are the OS 46 FX/AX similar to the Magnum/Asp 46?  That is, in regard to weight, power, fuel consumption, run characteristics?

I have an ASP 46 in a 62 ounce plane right now.  I re-worked the mounts of an old plane to get some flight tests on the ASP late last summer.  This old plane had been powered with an LA 46.  The weight of the test plane with the ASP 46, after adding 1.5 ounces of tail weight, was 59 ounces.  The ASP handled that very well and needed only 4.0 - 4.25 ounces of 5/22 fuel.  I did not notice if the added weight adversely affected the plane's performance.  The plane appeared to perform as it did before.  Besides, I was more interested in how the ASP ran.  I did nothing to the ASP but add a venturi and needle assembly from Randy.

The ASP, with no muffler, weighs 11.9 ounces.  The LA 46 (no muffler) is about 9 ounces.


I have a few flights on the new plane.  So far, the ASP is doing very well.  Maybe it will not do so well in hotter weather but we shall see. 

Since the fuel consumption of the ASP is rather low maybe a slightly shorter nose is all that is needed to be able to use these engines.

Jim - The AX & FX are 13.2 and 13.6 respectfully.  I have read, but not confirmed that the Magnum 46 series are OS Clones but lighter, which by definition means they are not clones.

One thing you can do if you are still in the building stage is to use universal mounts or drill it for both engines.  I have one of mine drilled for the LA and FX.

Ken

[Jim Svitko]

On my last two planes, I installed metal plates on the maple mounts.  I then tapped these plates for the engine.  If I have to change engines, I can change the plates and drill and tap for the new engine.  It is not that much work and I like being able to change engines if necessary.

I did not realize the AX and FX were that heavy.  Still, they might be something to consider using in an appropriate plane.

I never expected the Magnums to be clones of the FX/AX.  However, the Magnum and Asp appear to be identical.  I can see no difference between the two.

[Target]

Seems like using the .46axll in a 50-60 sized plane may be the way to go.
If you can use 2oz less fuel, that would help offset the weight difference, although it's further back.
Similar to running a 4 stroke, I'd think.

I believe that Randy Cuberly has run the OS.46AXII AND the OS.55AXII in SV planes already.

[Steve Helmick]

In the old Magnum/ASP engines (XL series), the .40, .46 and .53 use the same case casting, so the bigger the displacement, the lighter the engine gets, at least in terms of oz./cu.in.  The newer XLS series Magnums and ASP equivalents do the same, at least the .40/.46...the .52 may be a bit different, but I'm not sure about that. The ASP's have huge finned heads that may just be lighter than the Magnum XLS .52 head. Some weight could be saved by cutting down the ASP head fins by 50% or so and installing it on a Magnum XLS .52. It is perplexing that ASP and Magnum engine designators are not identical.

The legend is that the guy that designed some of the OS engines was hired to design various Pacific Rim engines, so they are all very similar. And especially in metric engines, it's pretty common for parts to be very similar dimensionally. From what I have gathered, the Magnum/ASP engines seem to have more conservative cylinder timing than a similar ball bearing OS, making them more tractable for CL stunt and sport use. I'm a big fan of the (discontinued) Magnum XLS .36. Quality is somewhere between Fox and OS...well above Fox...not perfect, but quite reasonable.    Steve

[Jim Svitko]

I also have an ASP 52.  It weighs 12.5 ounces without the muffler but including the venturi and needle assembly.  As near as I can tell, the case is the same as the 46 except for the "band" that encircles the bottom of the case.  This is to restore the case thickness due to the longer stroke.  The mounting hole spacings appear to be the same as the 46.

I have not yet run the 52 nor do I have a plane for it.  From what I have heard, the 52 will have no problem hauling a large plane, maybe something as big as the old Score.

I first heard of CL use of the Magnum/ASP from the guys at Just Engines in England.  I asked them what they did to make them CL friendly.  I was told they only added a venturi and needle assembly.  As was stated in a previous post, the guys at Just Engines said the timing was on the conservative side and nothing else was needed.  So, I got the 46, hoping they were right, and they were.

[Angelo Smyth]

Thanks guys. Not exactly sure what the Magnum/ASP engines are all about, but from what I gather so far here, the .46AX, although heavy, is powerful and might be better suited for use in larger-sized planes than one might use a .46LA series for.  For fun, I compared the weights of my .46AX (no muffler, no venturi or NVA) to my Gardner ST.51 (no muffler, but WITH an aluminum venturi and a NVA). The ST was STILL lighter by nearly 1/4 oz. I'm unsure how they might compare power-wise, but the AX seems to be a porky engine. When I weighed my .46LA, it was significantly lighter than either the ST or AX engines. If I were to actually use the AX, I would have to source a decent (lightweight) muffler (the original muffler is really boxy and a bit hefty even by itself), and a venture to fit it. All that with no real guarantee (to me, at least) that it would work well in a stunter.

[proparc]

I know this thread was specifically about the 46AX but, I would STRONGLY advise you to take a look at the 55AX. I can't post the video of mine running because of size but let me tell you, they are a stone cold winner!! I have got "stuff in the can" specifically for this engine-it's that good.

[Ken Culbertson]

Thanks guys. Not exactly sure what the Magnum/ASP engines are all about, but from what I gather so far here, the .46AX, although heavy, is powerful and might be better suited for use in larger-sized planes than one might use a .46LA series for.  For fun, I compared the weights of my .46AX (no muffler, no venturi or NVA) to my Gardner ST.51 (no muffler, but WITH an aluminum venturi and a NVA). The ST was STILL lighter by nearly 1/4 oz. I'm unsure how they might compare power-wise, but the AX seems to be a porky engine. When I weighed my .46LA, it was significantly lighter than either the ST or AX engines. If I were to actually use the AX, I would have to source a decent (lightweight) muffler (the original muffler is really boxy and a bit hefty even by itself), and a venture to fit it. All that with no real guarantee (to me, at least) that it would work well in a stunter.

I can only speak for my older FX.  When I swapped it for my LA to try it out it had drastically more power.  In fact too much power for the plane's 660sq" and 52 oz.  You are right about the muffler, it is a boat anchor.  I tried to find a pipe but I gave up.  I think with a pipe or a pipe/muffler it would be a really good stunt engine for a .60 size ship.  I was able to fast 4 cycle the whole pattern at 4.1 second laps.  Forget a 4/2, it was clear that I would have to figure out how to do an 8/4 cycle if I wanted to use it in that plane!  From what I understand, the AX has even more power than the FX

Ken