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General control line discussion => Open Forum => Topic started by: frank mccune on May 20, 2018, 08:08:15 AM
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Hi All:
While rummaging through my junk drawer the other day I found these two engines and wondered if I could build a stunter for each engine. If so, what are your thoughts regarding these engines as viable "stunt" engines. Bothe are a bit heavy but both are quite powerful for their sizes. The ASP weighs 19 oz. and the OS weighs 11 oz. Both weights are sans mufflers.
Both engines are new and have been had a stunt venture and nva fitted.
Suggestions for suitable airplane for each and perhaps more to the point, what should I do with these engines?
Tia,
Frank McCune
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Hi Frank
The OS, when fitted with a flat prop, will haul lots of "60" sized planes....I believe that Bob Hunt used one in his World Championship winning Genesis?
The ASP is unknown to me and the person I asked....
Have fun!
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Any Legacy 40 size plane for the OS .46LA. Up to 52 ounces on 63 foot eye to eye lines or shorter is perfect right out of the box. No mods are needed and low nitro up to 1000' msl. I don't have experience above that. I have flown a 57 ounce Chipmunk with the engine and it's about at it's limit on low nitro fuel. APC 11.5 x 4 prop. .015 lines. I bought the ASP .52 and converted it to c/l. A pretty good engine for 75 bucks new. It's pulling a 665 sq. in. Shark profile nicely. It took a while to break in but not as much as an Enya. Again on low nitro and a 12 x 5 Zinger.
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Perry...he wasn't asking about an LA.....
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If I can assume this is the OS 46 FSR, and from your weight description I think it can only be that, it will fly any modern stunt plane around 600 to 700 Sq in area and up to about 65 oz weight.
This engine was the staple stunt engine for quite a while during the late 70's and through the 80's. About the only thing that challenged it was the ST60 and in my humble opinion it (the OS) was better in most respects (lower vibration, less fuel used, easier to handle, and at least as much power). It will easily turn an 11.5 to 12 inch 4 to 4.5 pitch either two or three blade prop at more than 10,000 RPM if so desired.
An 11.5-4.5 Bolly Three blade is superb on one at about 9700 RPM.
The only downside now is that parts might be a problem, but I expect good used parts could be found! In fact I probably even have a limited supply of some for the postage!
I can't really speak to the ASP except to say that it's too heavy to be a serious consideration for Stunt!
Randy Cuberly
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Hi All:
While rummaging through my junk drawer the other day I found these two engines and wondered if I could build a stunter for each engine. If so, what are your thoughts regarding these engines as viable "stunt" engines. Bothe are a bit heavy but both are quite powerful for their sizes. The ASP weighs 19 oz. and the OS weighs 11 oz. Both weights are sans mufflers.
Both engines are new and have been had a stunt venture and nva fitted.
Suggestions for suitable airplane for each and perhaps more to the point, what should I do with these engines?
Tia,
Frank McCune
Hi
Dump the 61 and I assume you are talking a bout a OS 46 SF , if so I have many many kits that will work for that, SV11 , Evolution, Intrepid XL , Starfire , NOVAR, Classic etc.. Can you confirm what motor you have ?
Regards
Randy
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If I can assume this is the OS 46 FSR, and from your weight description I think it can only be that, it will fly any modern stunt plane around 600 to 700 Sq in area and up to about 65 oz weight.
This engine was the staple stunt engine for quite a while during the late 70's and through the 80's. About the only thing that challenged it was the ST60 and in my humble opinion it (the OS) was better in most respects (lower vibration, less fuel used, easier to handle, and at least as much power). It will easily turn an 11.5 to 12 inch 4 to 4.5 pitch either two or three blade prop at more than 10,000 RPM if so desired.
An 11.5-4.5 Bolly Three blade is superb on one at about 9700 RPM.
The 45 FSR had *much* more power than an ST60, it was in Scott Bair's report - even the way he ran it (slow). The problem was that it was hard to control with techniques of the day and the ring went away in short order. the 40/46VF was almost the same engine, with rear exhaust, and ABC, and those are still the gold standard for piped engine run quality.
I think this is a 46SF, which is also a very good stunt engine, and I have seen a lot more success in both run modes with the SF than the FSR. Randy's version of the 46SF was the best I have ever seen in 4-2 break mode, and easily matches/betters the ST60. It also works dandy with low-pitch tuned pipe props even with the stock muffler.
Brett
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The 45 FSR had *much* more power than an ST60, it was in Scott Bair's report - even the way he ran it (slow). The problem was that it was hard to control with techniques of the day and the ring went away in short order. the 40/46VF was almost the same engine, with rear exhaust, and ABC, and those are still the gold standard for piped engine run quality.
I think this is a 46SF, which is also a very good stunt engine, and I have seen a lot more success in both run modes with the SF than the FSR. Randy's version of the 46SF was the best I have ever seen in 4-2 break mode, and easily matches/betters the ST60. It also works dandy with low-pitch tuned pipe props even with the stock muffler.
Brett
Well I agree but his post said FS and the early OS FSR boxes said 45 FS with the Letter R lower on the box. That made me think that it was in fact an FSR.
In the 1980's at least here locally there were some after market rings available that solved the ring problem and some slight port changes solved the finicky run problems of the FSR. However there are a lot of folks around who simply think that good stunt engines should pop out of the box. I agree with them now that some are available. However at the time I was discussing that really wasn't true. The ST 46 was about the closest and it was miserably underpowered in stock form for the larger airplanes! The FSR with minimal work was in fact a very good stunt engine. Yes the VF in both sizes was significantly better with less work but it came along significantly later...As did the VF series.
However if He in fact has the 45 SF engine then Randy Smith's mods are definitely the answer, or it can be run as is fairly successfully with the right venturi/prop setup.
Incidentally the newer 46AXII and 55AX are terrific largely ignored Stunt engines with no serious mods necessary!
A proper sized venturi and Tongue muffler are all that is required to make superb stunt engines but few folks seem interested!
Randy Cuberly
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I think the OS boxes, as well as the crankcase say ":SR". The "F" in FSR stands for front rotor, just as the "R" in RSR stands for rear rotor. Both models used the same central crankcase. They came in 40 and 45, (plus others) The SF series came as a 40 or 46, ringed or ABN. OS did make a 40 FS, but in this case it stood for "four stroke".
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" Incidentally the newer 46AXII and 55AX are terrific largely ignored Stunt engines with no serious mods necessary!
A proper sized venturi and Tongue muffler are all that is required to make superb stunt engines but few folks seem interested!
Randy Cuberly "
Your right but they are heavy, I do not have much use for them because of the weight, as there are lghter motors just as powerful, But the OS 35 AX is a little jewel, and I have done many of those for people, it will go in where the Aero Tiger, Thunder Tger, Webra and Magnum 36 and 39 came out, and its a very light motor
Randy
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" Incidentally the newer 46AXII and 55AX are terrific largely ignored Stunt engines with no serious mods necessary!
A proper sized venturi and Tongue muffler are all that is required to make superb stunt engines but few folks seem interested!
Randy Cuberly "
Your right but they are heavy, I do not have much use for them because of the weight, as there are lghter motors just as powerful, But the OS 35 AX is a little jewel, and I have done many of those for people, it will go in where the Aero Tiger, Thunder Tger, Webra and Magnum 36 and 39 came out, and its a very light motor
Randy
I'm sure it's a terrific engine. However I thought we were talking about engines for larger airplanes like 55 to 60 oz.
That's the class of engine that he was basically referring to!
The 55AX weighs about the same as a PA65 (maybe just a tad more) and while it's not a pipe engine it does produce a lot of power and is very easy to deal with. I believe it runs almost as well as a side exhaust PA. for a lot less money. However if you want a piped engine the PA is in my opinion King!
Let's not talk apples and oranges!
Randy Cuberly
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I'm sure it's a terrific engine. However I thought we were talking about engines for larger airplanes like 55 to 60 oz.
That's the class of engine that he was basically referring to!
The 55AX weighs about the same as a PA65 (maybe just a tad more) and while it's not a pipe engine it does produce a lot of power and is very easy to deal with. I believe it runs almost as well as a side exhaust PA. for a lot less money. However if you want a piped engine the PA is in my opinion King!
Let's not talk apples and oranges!
Randy Cuberly
Hi Randy
Not talking apples and oranges, I was speaking about the AX line of OS motor, 46. 55. 35 , in my opinion the 55 is still heavy for what it is, Sure I agree with you, it can be made to run well for our use, but so can other similar motors, and it compares much closer to my side ex 51 instead of the 65
Nothing wrong with me saying I think the 35 AX is the best of that series . But if someone wants the 46 or 55 AX , you have graciously provided info for them to help them proceed with using it
Regards
Randy
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and Frank I have a CF prop, that is pretty much bolt on and fly, for the OS 46 SF, and is one of the very best prop you will ever find for that motor, hand made 12 1/4 x 4 1/4 Carbon
Randy
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Hi Randy et al. THE ENGINE IN QUESTION IS AN OS .46 SF. IT HAS ONE CONVENTINAL RING, STAMPED AH UNDER ONe lug. Will it pull score arf for stunt flying?
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Hi Randy et al. THE ENGINE IN QUESTION IS AN OS .46 SF. IT HAS ONE CONVENTINAL RING, STAMPED AH UNDER ONe lug. Will it pull score arf for stunt flying?
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Hi Frank
YES it will pull a Score unless it has a low compression/worn out condition, they are powerful motor, If I was you I would look for a backup ring just in case
Randy
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Incidentally the newer 46AXII and 55AX are terrific largely ignored Stunt engines with no serious mods necessary!
A proper sized venturi and Tongue muffler are all that is required to make superb stunt engines but few folks seem interested!
Randy Cuberly
Terrific is right. 55AX's are happening!! H^^
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and Frank I have a CF prop, that is pretty much bolt on and fly, for the OS 46 SF, and is one of the very best prop you will ever find for that motor, hand made 12 1/4 x 4 1/4 Carbon
Randy
That is very similar to the props we were using with the stock engines - 12.5-4.5 2-blade Eather and other props that would have worked well on 46VFs, with a little more pitch.
Brett
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Terrific is right. 55AX's are happening!! H^^
I have known about the AX's for quite some time. One of the questions I always had was, how do they compare to our classic ST60's. I ran both them, head to head and, the ST60 has more of a "low down grunt" and, the 55AX simply runs away from the "Big Cat" up top in the higher RPM range. Also, the 55AX DEFINITELY seems to prefer a hotter plug then the Tiger. They are both VERY QUICK hand starting motors, in the hands of an experienced flyer, they are both beautiful running motors that will certainly do a good job for you without question.