ASP .61 and OS .46 FS as stunt engines????? Plane for each?

[frank mccune]

     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

[peabody]

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!

[Perry Rose]

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.

[peabody]

Perry...he wasn't asking about an LA.....

[Randy Cuberly]

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

[RandySmith]

     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

[Brett Buck]

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

[Randy Cuberly]

  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

[bill bischoff]

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".

[RandySmith]

 " 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

[Randy Cuberly]

" 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

[RandySmith]

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

[RandySmith]

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

[frank mccune]

          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?
.                               



 
.

[RandySmith]

          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?
.                               



 
.

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

[proparc]

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!!

[Brett Buck]

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

[proparc]

Terrific is right. 55AX's are happening!!

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.