OS .25FP Any good???
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OS .25FP Any good???
Yup I am new to this u-control stuff. I have been flying a sterling yak 9 with a Fox 35, I hate having to have a special fuel for it. Last weekend an older club member offered up a lightly used OS 25FP for a good price. Is this engine anygood? performace wise is it better than the Fox 35?
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RE: OS .25FP Any good???
When the FP series went out of production I went around buyinig up all of the FP motors I could find, till thiis day I still have the 15FP, 20FP, 25FP, 35FP and 40FP in my collectiion, some new in the box (they are not for sale). I have 7 OS-25FP's in my collectiion, four of them will be used on a profile scale B-29. They are a great engine, remember it has a plain bushing but runs great. It being run for Stunt it might requiire some timing changes but worth buyinig.
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RE: OS .25FP Any good???
ORIGINAL: iflyg450
nope it does not have a blue head, what does the blue head mean?
nope it does not have a blue head, what does the blue head mean?
Not real sure other than some kind of blue head OS .25 on another fliers airplane.
Was a new unbroken in engine and hard to start and wanting to seize so did not get to observe much about how it ran.
Playing 25+years catch up in C/L from this end.
David
#7
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RE: OS .25FP Any good???
The blue head and the rest of the motor for that matter is an OS25LA the successor to the 25FP.
Just one word on fuel. While the 25 will run on R/C fuel it needs a higher oil content then many of the cheaper brands of fuel. It is a plain bushing engine and needs more lubrication then a ball bearing equivalent. Something around 20%oil is at least the minimum that I would use. I personally run Powermaster 10/22 in most of mine but Sig and some others are all good. Stay away from all synthetic fuel mixtures for C/L. Since you have no throttle control if you go lean in flight you will have to run the tank out in that condition. Lifespan of your engine can go down the drain immediately. Bottom line is use a fuel with some castor in it.
dennis
Just one word on fuel. While the 25 will run on R/C fuel it needs a higher oil content then many of the cheaper brands of fuel. It is a plain bushing engine and needs more lubrication then a ball bearing equivalent. Something around 20%oil is at least the minimum that I would use. I personally run Powermaster 10/22 in most of mine but Sig and some others are all good. Stay away from all synthetic fuel mixtures for C/L. Since you have no throttle control if you go lean in flight you will have to run the tank out in that condition. Lifespan of your engine can go down the drain immediately. Bottom line is use a fuel with some castor in it.
dennis
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RE: OS .25FP Any good???
I use a omega 15% in all my planes then add obout 3oz of castor to a new gallon. I think for $25 this engine sounds like a good buy. It should move my Yak9 pretty good.
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RE: OS .25FP Any good???
ORIGINAL: iflyg450
I use a omega 15% in all my planes then add obout 3oz of castor to a new gallon. I think for $25 this engine sounds like a good buy. It should move my Yak9 pretty good.
I use a omega 15% in all my planes then add obout 3oz of castor to a new gallon. I think for $25 this engine sounds like a good buy. It should move my Yak9 pretty good.
Good Luck
Dwayne
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RE: OS .25FP Any good???
ORIGINAL: iflyg450
Is the FP a Steal Piston engine?
Is the FP a Steal Piston engine?
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RE: OS .25FP Any good???
ORIGINAL: cutaway
I know the .35 was available in iron/steel P/L as well as ABC. AFAIK, the FP ABC's were actual chrome, not nickle.
I know the .35 was available in iron/steel P/L as well as ABC. AFAIK, the FP ABC's were actual chrome, not nickle.
No FP was ever an abc in spite of what might be on the box or the adds. They were origionally iron/steel then aluminum/ steel liner with nickel plating. OS only chromes it's high performance engines anymore, and they probably farm that out.
#17
RE: OS .25FP Any good???
Ifly,
Same "type" of fuel, yes, but not 29% oil, all of which is castor.
OS instructions for the FP series, dating from about 1991, state that fuel containing 20% castor oil is "correct." No mention of any synthetic oil %... (Further details: OS recommended 75% methanol, 20% castor oil, 5% nitro for initial break-in and/or general use, AND, later, after break-in, up to 65% methanol, 20% castor oil and 15% nitro for higher performance.)
With an iron piston and steel sleeve, you shouldn't need any more than the recommended 20% total oil. Even with 20% all-castor, that's a lot less mess than 29% castor.
Since OS recommends all-castor, you may find that ANY synthetic % - say an 18% castor, 2% synthetic oil portion - could prevent the castor varnish build-up that older types of iron-in-steel engines found to be a good thing. As wear occurred, that varnish layer seemed to maintain good seal and durable life. Synthetics are detergent, and can "wash off" the layer as it tried to form. However, the detergent effect may not harm things if the synthetic % is up to 5% (i.e., 15% castor, 5% synthetic.)
Newer (ABC/AAC/ABN) engines are manufactured to expand to "ideal" tolerances at running temps. A varnish coating would change the heating and cooling, and disrupt that intended fit at operating conditions.
Dennis is right that no FP was ABC, but I think the later ones were ABN - high silicon aluminum piston in a nickle-plated brass sleeve. Tower Hobbies had a near clone of the 40FP (many parts interchange) manufactured for a while. One main difference was that the Tower 40 was true ABC (hi-silicon Al piston running in a chromed brass sleeve. )
Same "type" of fuel, yes, but not 29% oil, all of which is castor.
OS instructions for the FP series, dating from about 1991, state that fuel containing 20% castor oil is "correct." No mention of any synthetic oil %... (Further details: OS recommended 75% methanol, 20% castor oil, 5% nitro for initial break-in and/or general use, AND, later, after break-in, up to 65% methanol, 20% castor oil and 15% nitro for higher performance.)
With an iron piston and steel sleeve, you shouldn't need any more than the recommended 20% total oil. Even with 20% all-castor, that's a lot less mess than 29% castor.
Since OS recommends all-castor, you may find that ANY synthetic % - say an 18% castor, 2% synthetic oil portion - could prevent the castor varnish build-up that older types of iron-in-steel engines found to be a good thing. As wear occurred, that varnish layer seemed to maintain good seal and durable life. Synthetics are detergent, and can "wash off" the layer as it tried to form. However, the detergent effect may not harm things if the synthetic % is up to 5% (i.e., 15% castor, 5% synthetic.)
Newer (ABC/AAC/ABN) engines are manufactured to expand to "ideal" tolerances at running temps. A varnish coating would change the heating and cooling, and disrupt that intended fit at operating conditions.
Dennis is right that no FP was ABC, but I think the later ones were ABN - high silicon aluminum piston in a nickle-plated brass sleeve. Tower Hobbies had a near clone of the 40FP (many parts interchange) manufactured for a while. One main difference was that the Tower 40 was true ABC (hi-silicon Al piston running in a chromed brass sleeve. )
#18
RE: OS .25FP Any good???
ORIGINAL: dennis
No FP was ever an abc in spite of what might be on the box or the adds. They were origionally iron/steel then aluminum/ steel liner with nickel plating. OS only chromes it's high performance engines anymore, and they probably farm that out.
ORIGINAL: cutaway
I know the .35 was available in iron/steel P/L as well as ABC. AFAIK, the FP ABC's were actual chrome, not nickle.
I know the .35 was available in iron/steel P/L as well as ABC. AFAIK, the FP ABC's were actual chrome, not nickle.
No FP was ever an abc in spite of what might be on the box or the adds. They were origionally iron/steel then aluminum/ steel liner with nickel plating. OS only chromes it's high performance engines anymore, and they probably farm that out.
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RE: OS .25FP Any good???
ORIGINAL: iflyg450
A magnet sticks to the piston so I guess its a steel one, does this mean that this engine needs the same type of fuel as a Fox 35??
A magnet sticks to the piston so I guess its a steel one, does this mean that this engine needs the same type of fuel as a Fox 35??
Dwayne
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RE: OS .25FP Any good???
Well I think I just go with a OS 25LA-s I have been very happy with the way my Nobler flies with the 46LA-s it just runs so nice. I want to thank everyone who took the time to post some of the most informed information that I have seen on this site in a very long time.
#21
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RE: OS .25FP Any good???
Your correct it is aluminum/brass. Old age is catching up to me.
As has been said many times the OS40FP, the Thunder Tigre 40GP and the Tower 40 were all completely interchangable in parts. I have seen motors with parts from all 3 of the motors combined. But for my money the best was the Tower, 2nd the Thunder Tigre and a distant 3rd the OS fP.
If you see a Tower for sale on these forums or Flea bay and it looks good give yourself a treat and buy it
As has been said many times the OS40FP, the Thunder Tigre 40GP and the Tower 40 were all completely interchangable in parts. I have seen motors with parts from all 3 of the motors combined. But for my money the best was the Tower, 2nd the Thunder Tigre and a distant 3rd the OS fP.
If you see a Tower for sale on these forums or Flea bay and it looks good give yourself a treat and buy it
#22
RE: OS .25FP Any good???
ORIGINAL: dennis
...As has been said many times the OS40FP, the Thunder Tigre 40GP and the Tower 40 were all completely interchangable in parts. I have seen motors with parts from all 3 of the motors combined...
...As has been said many times the OS40FP, the Thunder Tigre 40GP and the Tower 40 were all completely interchangable in parts. I have seen motors with parts from all 3 of the motors combined...
Here is a TT .10 venturi:
George
#23
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RE: OS .25FP Any good???
ORIGINAL: iflyg450
Well I think I just go with a OS 25LA-s I have been very happy with the way my Nobler flies with the 46LA-s it just runs so nice. I want to thank everyone who took the time to post some of the most informed information that I have seen on this site in a very long time.
Well I think I just go with a OS 25LA-s I have been very happy with the way my Nobler flies with the 46LA-s it just runs so nice. I want to thank everyone who took the time to post some of the most informed information that I have seen on this site in a very long time.