os engines
07-19-2009 | 08:15 AM
#1
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From: Glen Burnie, MD
os engines
Can anyone please explain the difference between an OS MAX .46 LA and an OS MAX .46 AX ? which is better and why ? I am putting of them in a Hanger 9 P-51 PTS, and would like to know which to go with. Thank you
07-19-2009 | 08:20 AM
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From: Perth Australiaaustralia, AUSTRALIA
RE: os engines
the 46la is bushed and the 46ax is bearings the ax with the bearings produce abit more grunt because less friction with bearings and more friction with bushed bearings
07-19-2009 | 10:44 AM
#5
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RE: os engines
The bearings of the AX have little to do with the power of the engine. It has more to do with the timing of the crank and sleeve, and the higher flow of the carb.
Nothing inherently wrong with plain bearing engines. The engine in every car on the road uses them.
For beginners, they are much easier to clean when you make contact with the ground. Nobody plans on crashing a lot, but it does happen.
One thing about plain bearing engines, they do need fuel with slightly more oil.
Nothing inherently wrong with plain bearing engines. The engine in every car on the road uses them.
For beginners, they are much easier to clean when you make contact with the ground. Nobody plans on crashing a lot, but it does happen.
One thing about plain bearing engines, they do need fuel with slightly more oil.
07-19-2009 | 11:12 AM
#6
RE: os engines
As has been pointed out, the LA is a bushing engine while the AX uses ball bearings on the crankshaft. The AX is also ported much differently and develops more power. The LA is smaller and a little lighter with an air bleed type carb while the AX has a much larger, standard type carb. There are no tuning differences between the two other than the low-end needle being opposite between the engines. Basically the LA is an economical, entry level engine that will work great for most trainers and a lot of lighter sport planes while the AX is more of a premium, higher performance engine. I own/owned both and been happy with them.
In my personal opinion though, if you think you are serious about the hobby and don't mind paying a little extra, go with the AX. Both engines are great but you'll find that there will more applications for the more powerful AX as you move on into different airplanes. If you are trying to stick to a budget though, the LA will work fine and you can also use it certain planes down the road.
In my personal opinion though, if you think you are serious about the hobby and don't mind paying a little extra, go with the AX. Both engines are great but you'll find that there will more applications for the more powerful AX as you move on into different airplanes. If you are trying to stick to a budget though, the LA will work fine and you can also use it certain planes down the road.
07-19-2009 | 11:44 AM
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From: Glen Burnie, MD
RE: os engines
Well i currently have the AX in a Sig. Kadet mark 2, the build is finished, just need to cover it. The P-51 is ready to go, minus engine. Was just trying to figure out what the differences between the 2 engines were and which was better suited for what. So from here i guess i will be buying another AX for the 51 or should i get something a little more powerful ? I have a royal .45 but am missing the carb and have NO clue where to get one for it. Also have an unidentified plane that i posted some pics on here a couple of months ago that no one could really say for sure what it was.... Plane was given to me by my uncle and he said it was a trainer, from the 2 replys i got about the pics. all they could say was it is similar to a viper and someone with lots of stick time should take it up first. Havnt a clue what the engine in that one is. Seems much smaller than the .46 tho
07-19-2009 | 04:00 PM
#9
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RE: os engines
Follow Chucks advice!! Or better yet, if you have deeper pockets get the .55 AX, we have been using that engine in 60 size ARFs and it works out great unless you want to fly 3-D.
I used to fly Fun Fly events and my main plane was the 40 size Up-Roar, I used nothing but the .46 LA engines in them unless I was breaking in something else. The LA is a very good engine but there are a lot of differences between it and the AX line. When you find them on sale they are really a pretty good buy and great for trainers. The .40 is really under powered but the difference between the .40 and .46 are night and day!
I used to fly Fun Fly events and my main plane was the 40 size Up-Roar, I used nothing but the .46 LA engines in them unless I was breaking in something else. The LA is a very good engine but there are a lot of differences between it and the AX line. When you find them on sale they are really a pretty good buy and great for trainers. The .40 is really under powered but the difference between the .40 and .46 are night and day!
07-19-2009 | 04:17 PM
#10
RE: os engines
Simply put, the LA engines are cheaper, lighter and less powerful than the AX engines are. They are for trainers and lower speed sport and scale planes. The AX will give you more speed with the P51 when you're ready, but don't count out other maker's engines either. A Thunder Tiger .46 Pro is close to the price of the .46 LA, but has the performance of the AX.
07-19-2009 | 05:21 PM
#11
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RE: os engines
why are we only recommending os engines? i have a ax55 and the thing is a pain in the rear. hasnt deadsticked but the midrange is horrible, it flies slower at half throttle than it does at 1/4 throttle. i have no throttle response between 1/4 and 3/4 throttle, just a lot of gargleing. my idle is spot on, it will idle all day. im rich on the high end but not horribly rich. the engine crazy hot when i land, it easily boils any water put on it (wont boil water after about 2o seconds). its still breaking in i only have 5 tanks through it but for all the talk about os being easy to break, doesnt seem to be true. of my 5 engines the ax has been the worst during breakin, even my magnum 4 stroke runs better than this ax (breaking in the magnum). i also have a os 40fp that will die on me for no reason that i can think of while in flight, it will run great one day then bad the next.
get a gms .47 it has a slight blurble in the midrange if your idle isnt perfect but it is a very reliable engine and will pull that p-51 around quite well. their is no reason to spend 120-150 bucks on a engine that doesnt run much better than a 70 dollar one. espically if you are just learning and have the highest chance of a crash. if you want more power than a gms 47 get a magnum 52.
get a gms .47 it has a slight blurble in the midrange if your idle isnt perfect but it is a very reliable engine and will pull that p-51 around quite well. their is no reason to spend 120-150 bucks on a engine that doesnt run much better than a 70 dollar one. espically if you are just learning and have the highest chance of a crash. if you want more power than a gms 47 get a magnum 52.
07-19-2009 | 07:00 PM
#12
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RE: os engines
ORIGINAL: jimmyjames213
why are we only recommending os engines? i have a ax55 and the thing is a pain in the rear. hasnt deadsticked but the midrange is horrible, it flies slower at half throttle than it does at 1/4 throttle. i have no throttle response between 1/4 and 3/4 throttle, just a lot of gargleing. my idle is spot on, it will idle all day. im rich on the high end but not horribly rich. the engine crazy hot when i land, it easily boils any water put on it (wont boil water after about 2o seconds). its still breaking in i only have 5 tanks through it but for all the talk about os being easy to break, doesnt seem to be true. of my 5 engines the ax has been the worst during breakin, even my magnum 4 stroke runs better than this ax (breaking in the magnum). i also have a os 40fp that will die on me for no reason that i can think of while in flight, it will run great one day then bad the next.
get a gms .47 it has a slight blurble in the midrange if your idle isnt perfect but it is a very reliable engine and will pull that p-51 around quite well. their is no reason to spend 120-150 bucks on a engine that doesnt run much better than a 70 dollar one. espically if you are just learning and have the highest chance of a crash. if you want more power than a gms 47 get a magnum 52.
why are we only recommending os engines? i have a ax55 and the thing is a pain in the rear. hasnt deadsticked but the midrange is horrible, it flies slower at half throttle than it does at 1/4 throttle. i have no throttle response between 1/4 and 3/4 throttle, just a lot of gargleing. my idle is spot on, it will idle all day. im rich on the high end but not horribly rich. the engine crazy hot when i land, it easily boils any water put on it (wont boil water after about 2o seconds). its still breaking in i only have 5 tanks through it but for all the talk about os being easy to break, doesnt seem to be true. of my 5 engines the ax has been the worst during breakin, even my magnum 4 stroke runs better than this ax (breaking in the magnum). i also have a os 40fp that will die on me for no reason that i can think of while in flight, it will run great one day then bad the next.
get a gms .47 it has a slight blurble in the midrange if your idle isnt perfect but it is a very reliable engine and will pull that p-51 around quite well. their is no reason to spend 120-150 bucks on a engine that doesnt run much better than a 70 dollar one. espically if you are just learning and have the highest chance of a crash. if you want more power than a gms 47 get a magnum 52.
07-19-2009 | 07:55 PM
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From: Glen Burnie, MD
RE: os engines
Outstanding. Looks like a .55 orthe AX now... thanks everyone! Now can anyone point me in the right direction for finding a carburator for the royal .45 please?
07-19-2009 | 10:19 PM
#15
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RE: os engines
ORIGINAL: Gray Beard
Most of the clubs I have belonged to have someone that can teach you to tune an engine correctly. There shouldn't be any of the fat gurggling you are describing and no mid range lag. It's a lot easier to make an engine run poorly then correctly if you are off on both needles. Sounds like you are a bit out of the ball park with your tune.
ORIGINAL: jimmyjames213
why are we only recommending os engines? i have a ax55 and the thing is a pain in the rear. hasnt deadsticked but the midrange is horrible, it flies slower at half throttle than it does at 1/4 throttle. i have no throttle response between 1/4 and 3/4 throttle, just a lot of gargleing. my idle is spot on, it will idle all day. im rich on the high end but not horribly rich. the engine crazy hot when i land, it easily boils any water put on it (wont boil water after about 2o seconds). its still breaking in i only have 5 tanks through it but for all the talk about os being easy to break, doesnt seem to be true. of my 5 engines the ax has been the worst during breakin, even my magnum 4 stroke runs better than this ax (breaking in the magnum). i also have a os 40fp that will die on me for no reason that i can think of while in flight, it will run great one day then bad the next.
get a gms .47 it has a slight blurble in the midrange if your idle isnt perfect but it is a very reliable engine and will pull that p-51 around quite well. their is no reason to spend 120-150 bucks on a engine that doesnt run much better than a 70 dollar one. espically if you are just learning and have the highest chance of a crash. if you want more power than a gms 47 get a magnum 52.
why are we only recommending os engines? i have a ax55 and the thing is a pain in the rear. hasnt deadsticked but the midrange is horrible, it flies slower at half throttle than it does at 1/4 throttle. i have no throttle response between 1/4 and 3/4 throttle, just a lot of gargleing. my idle is spot on, it will idle all day. im rich on the high end but not horribly rich. the engine crazy hot when i land, it easily boils any water put on it (wont boil water after about 2o seconds). its still breaking in i only have 5 tanks through it but for all the talk about os being easy to break, doesnt seem to be true. of my 5 engines the ax has been the worst during breakin, even my magnum 4 stroke runs better than this ax (breaking in the magnum). i also have a os 40fp that will die on me for no reason that i can think of while in flight, it will run great one day then bad the next.
get a gms .47 it has a slight blurble in the midrange if your idle isnt perfect but it is a very reliable engine and will pull that p-51 around quite well. their is no reason to spend 120-150 bucks on a engine that doesnt run much better than a 70 dollar one. espically if you are just learning and have the highest chance of a crash. if you want more power than a gms 47 get a magnum 52.
get what ever engine you want, its your choice. i would buy a gms .47 but thats just me since i can get two of them for the price of one ax55. unless you need more power, which you dont (gms will be more than enough). if you want more power go ahead.
07-20-2009 | 07:46 AM
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From: Va Beach, VA
RE: os engines
ORIGINAL: HighPlains
The bearings of the AX have little to do with the power of the engine. It has more to do with the timing of the crank and sleeve, and the higher flow of the carb.
Nothing inherently wrong with plain bearing engines. The engine in every car on the road uses them.
For beginners, they are much easier to clean when you make contact with the ground. Nobody plans on crashing a lot, but it does happen.
One thing about plain bearing engines, they do need fuel with slightly more oil.
The bearings of the AX have little to do with the power of the engine. It has more to do with the timing of the crank and sleeve, and the higher flow of the carb.
Nothing inherently wrong with plain bearing engines. The engine in every car on the road uses them.
For beginners, they are much easier to clean when you make contact with the ground. Nobody plans on crashing a lot, but it does happen.
One thing about plain bearing engines, they do need fuel with slightly more oil.
07-20-2009 | 04:55 PM
#18
My Feedback: (-1)
RE: os engines
I no longer buy OS two strokes for myself but I also don't use anything smaller then a .91 two stroke glow engine. If I need a small two stroke I have boxes of them under my bench. I started using the SK line of engines in the glows and they suite my uses better then the OS line of two strokes. At a hundred bucks a pop they even fit my wallet. I use almost nothing but four stroke glows and if I have to buy one it is a YS but I also like the OS and Saitos. I don't buy OS or Saito though. If someone says here you go, you can have this but it can stand some work then it's on my bench getting a rebuild right away. It was a big surprise how many people don't rebuild engines and just toss them or give them away. Works for me though!!! After 1.20 glow I head right to gas and save myself more money in engine cost and the price of glow fuel.
I feel OS still makes the best of the small two stroke glow engines and to date I have never had a problem with one, with or without bearings!
I feel OS still makes the best of the small two stroke glow engines and to date I have never had a problem with one, with or without bearings!
07-20-2009 | 06:36 PM
#19
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RE: os engines
im running a apc 13x4, i tried a 11x6 but same problem. i was thinking about putting a 10x7 on it, but it was screaming with the 11x6 i dont want to over rev it.
ill give it a tank then start leaning it. just bought a tach so ill check rpm's the weekend
ill give it a tank then start leaning it. just bought a tach so ill check rpm's the weekend
07-20-2009 | 11:02 PM
#20
My Feedback: (1)
RE: os engines
OS makes a ridiculous recommend prop selections for this engine.
As you increase the load on an engine, the acceptible needle range that the engine will run with gets to zero. Either their marketing department thinks that they will sell more engines if people compare the recommended prop size (ie., if this one turns bigger props, it must be more powerful), or they are trying to make a very quiet engine. Either way, those props are way too much load.
Depending on the model, I would try either a 12x6 or 11x7 as a starting point. Shoot for an rpm of at least 11,000. The engine is really just a pumped up .45, so it may not flow very well internally.
Recommended Props: 12x7-8, 13x6-7
Depending on the model, I would try either a 12x6 or 11x7 as a starting point. Shoot for an rpm of at least 11,000. The engine is really just a pumped up .45, so it may not flow very well internally.
07-20-2009 | 11:06 PM
#21
My Feedback: (-1)
RE: os engines
The 11X6 should be right in the ball park for props on a .46. You really should be sending it in for a check up to see if something is wrong. There service really is pretty fast so you won't be down too long. Getting that hot that quick is a bad thing!!
07-20-2009 | 11:09 PM
#23
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RE: os engines
im useing a 13x4. useing the 1-2 dia/pich rule it will give a similer load to a 12x6. i know a lot of people run this prop for 3d so i should be fine. i think it just needs a few more tanks. it will be fine, ill complain this weekend if it still runs bad 
07-21-2009 | 09:59 PM
#24
RE: os engines
I have to agree with a lot of the above suggestions. On the 51, a AX makes sense. I don't know, but I"ve never disliked the the plain bearing TT GP42's that I've had. Similar to the OS LA 40. I think they have great purpose and on something a little smaller, they would be just great. My first trainer was a Kadet Senior that I put a TT GP42 on it. Not great power, but I had a blast with it. So it really comes down to how much you can spend and what you're putting it on. Nothing wrong with choosing a OS 40 AX.
