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Engine basics => Engine set up tips => Topic started by: Joe Messinger on May 22, 2010, 10:36:53 PM
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Well, here's another 'Fox" question(s) . . .
I put together an S-1 Ringmaster last winter and the only engine I have that might be suitable for it is a Fox .25. I did say "might be" because I know very little about the Fox .25 engines. This one is marked 'RC' on the case and has a bolt on c/l venturi. No muffler or provision for one. Here are my questions:
*Is the "Fox Burp" inherent to the .25 as it is with the .35 & .40 (perhaps others)?
*Is there a boost port and might blocking that (if it has one) help?
*Is the 'RC' ported differently from the standard c/l engines?
*Are there any other NVAs that will work on the .25?
*Would a 9/5 prop be suitable for this Ringmaster/Fox .25 set up?
I don't have any ambition to compete with this Ringmaster, just try and have some fun sport flying with it.
I'm sure an OS, LA .25 engine would be a much better choice for this plane but the Sterling kit and Fox .25 engine were given to me by a friend and I would like to be able to fly it, pretty much, as it was given to me.
Thanks for any advice and suggestions.
Joe
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*Is the "Fox Burp" inherent to the .25 as it is with the .35 & .40 (perhaps others)?
YES. But to reduece the burp lower the pitch and rev-up the engine
*Is there a boost port and might blocking that (if it has one) help?
Yes..But I never tryed to block one before It's not a boost port it's a intake that needs to be smaller
*Is the 'RC' ported differently from the standard c/l engines?
NO the five I have are the same
*Are there any other NVAs that will work on the .25?
YES...Any super tiger..HOWEVER you will need the venturi opened up and washers to fit the center of the hole
*Would a 9/5 prop be suitable for this Ringmaster/Fox .25 set up?
YES and 9.5x4.5 10x4
USE ALL CASTOR FUEL.
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If its the light 70s one, vertical intake, two weeny screws ,
they work rather well .Little ribs below exhaust port ,
usually a bolt hole over and under cenre of exhaust .
and / or lugs fore and aft. Take a .35 silencer .
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Theres a 19 the same but 1 fin lower , thats a howler
as the holes are the same size and the timings hotter.
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Like Nitro , will switch / change tone . 9x4 if its lugging.
these are the one piece case ones.NOT the B.B. schnerule.
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If it is the Four bolt backplete, six bolt head, baffled piston, non-ball bearing shaft version with th verticle venturi/carb that Matthew seems to be referring to,, then it probably will not have the "Fox Burp" (none of mine did). It already has a fairly small by-pass. It does not 4-2-4 break easily, but runs well in a Rich two setting. a 9 X 4 to 9 X 5 prop and up to 15% nitro with 25 to 30% CASTOR oil should give you a pretty good run.
Bigiron
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Don't cheat on the oil either. The Engines don't have pads on the wrist pin and have been known to scour a line on the liner if abused.
Dennis
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Thanks to all who answered my questions.
Marvin: Yes, the engine is the same as you described.
I'll install another NVA and give it a try.
Regards,
Joe
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My flying buddy Tom has an S-1 ( average to slightly porky weight) with the 4 bolt .25. Stock except for a strap on lightweight tounge muffler. 10-4 wood prop ( Zinger maybe?)
Good solid slightly rich 2- cycle run pulls the plane around on .015 X 60 with good tension and lap times around 5 secs. No burp or funny run, stunts well and pretty easy to fly. It seems to like a Fox Miracle plug with PowerMaster GMA 10% nitro all castor fuel.
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JOE...Hows the engine working now!!??
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Scott,
Well, I haven't gotten around to changing the NVA on the Fox.25 yet or trying the engine/plane. That project got sidelined due repairs being made on another plane. Unexpected encounter with a field box while landing resulted in a broken wing. Proves field boxes are allot tougher than planes. Of course field boxes don't fly so good although I felt like hurling the thing as far as I could after the incident. Though better of it because I would then need to repair both the plane and the field box.
I hope to get the broken plane back in the air this week and will see what the Ringmaster/Fox.25 will do.
Regards,
Joe
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Unexpected encounter with a field box while landing
When I was a kid my "field box" was my back pocket. Now, I make sure to keep my field box at least six feet away from the expected flight line of the plane, and fetch what I need as I need it.
Of course, I'm flying with a bunch of old RC guys who want to stand right next to my field box, so there's more than the safety of the plane involved...