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General control line discussion => Open Forum => Topic started by: Tom Rounds on January 23, 2009, 05:25:10 PM
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Some feedback desired. Would on OS .25LA fly the same profile plane as the Fox .35? Both engines weigh almost the same and most of todays engines make a lot more power than the old Fox .35.
Thanks,
Lineflyer
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I'd say that a Fox would do better on a really large/heavy model, simply because it will generally swing a bigger prop...but you'd also need 20% nitro or more. I'm talking about designs over 600 sq. in. and/or over 50 oz. If the model is more like 450 sq. in. and under 40 oz, I think the .25LA would be a better choice, especially a profile. I don't know how big a Twister is, but mine's 45.5 oz and flies well with a Magnum XLS .36. It wouldn't fly worth beans with a .25LA. D>K Steve
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Hi There, If your are planning to put your LA .25 on a Yak, Mustang, Ringmaster as in the old or new revitalized versions which are now once again available, go for the LA .25 and have a ball! I have been flying old Heavy original Sterling versions of these models with several LA .25's and a couple of FP .20's and am amazed at how much better these planes fly than they ever did with the old Fox .35's! Use an APC 9 X 4 or 10 X 4 prop on the newer engines and those old wings begin to work like never before. I use 58' of line .015 eyelet to eyelet. MY Mustangs have flaps and the engines are set up with muffler pressure cause that's the way I like it!
Tally Ho,
Phil Spillman
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Hi Tom,
The LA 25 and FP 25 are great replacement engines for the Fox 35 in older kit planes of the size around 40 inches. They run smoother than the Fox 35 and give you less vibration in the nose of the profiles. The LA 25 uses less fuel also, and puts out a bit more power.
Too bad the bolt holes for the two are not the same , but it is easy to drill out the mounting holes , glue in some hardwood dowls then redrill new mounting holes if the plane has had a Fox in it.
It sure makes an old Ringmaster fly better!
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Hi Tom,
I would go with the OS .25s over the fox for all the reasons mentioned, and if you use their stock mufflers you will have the benefit of a very quiet flying plane. Also, you will avoid the Horrible Bad Karma that comes with using any fox engine. n1
I have only flown the OS .25s and .20s, but my guess is that the Brodak .25 would also be better.
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put the OS on a profile, save te hfox for a BiSlob
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Hi Tom,
I would go with the OS .25s over the fox for all the reasons mentioned, and if you use their stock mufflers you will have the benefit of a very quiet flying plane. Also, you will avoid the Horrible Bad Karma that comes with using any fox engine. n1
I have only flown the OS .25s and .20s, but my guess is that the Brodak .25 would also be better.
Rudy,
What is this horrible bad karma that comes with using a any Fox engine?
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I think your leg is being pulled, De. Rudy (and a couple of others) genuinely despise FOx engines.
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Hi De, Ralph,
Please see the private email I sent you on this fox = "Bad Karma" issue. Robert's great forum is not the place for an open discussion on this horrific topic. This is why others have just made general comments against fox, they were trying to be polite, and respectful of Robert's peaceful forum format. I was trying to do the same by being so oblique. I thought everyone knew about this issue, but I guess not? Please ask any other questions offline via private email. TIA
Regards, H^^
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De,
People that can't get a Fox to run like you or Marvin or GMA or the Silver Fox or dozens of others simply have no KARMA not to mention any skill with 2 stroke engines. That's just my opinion.
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Now Hold on Just one Minute Mr. Blakensip! Some of my best friends are Fox Engines! But here is what I had to do to get ....close to them: Bought Magic Blue head from Happy Camper Engine Man $25.00 or so; Bought stuffer back plate from Fox itself; estimated price +/- 12.00, Bought and installed ST NVA estcost$13.95, as I estimate these cost I am getting close to $50.00 extra for that "Friendly" Fox feeling! Has nothing to do with Karma nor any other Mideastern Religion! Whereas the LA's, FP's, and Brodak's come with a nice muffler as ABN engineering which makes them run smoother for no extra charge!
I know that Lew Woolard and Marvin Denny have worked their magic on many Foxes and for that we are all grateful, those men are very skilled engine men while as for me and many others once I start to mess with the engine I'll have more money to spend out to replace the parts I screwed up! What's Karma anyway?
Phil Spillman
PS DeHill once told me all about what one should do to optimize a Fox. He was spot on and it worked for 30 runs on two engines! And then the cranks both let loose! There was the matter of heat treating the enlarged ID of the shaft which I either forgot or he forgot to mention to me!
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De,
People that can't get a Fox to run like you or Marvin or GMA or the Silver Fox or dozens of others simply have no KARMA not to mention any skill with 2 stroke engines. That's just my opinion.
Thanks for the compliment Rick, but I don'r rate up there withMarvin, George, The Silverfoxx, or the other real pros. They Know what they are doing; I just highly suspect what I am doing...
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Phil Spillman
PS DeHill once told me all about what one should do to optimize a Fox. He was spot on and it worked for 30 runs on two engines! And then the cranks both let loose! There was the matter of heat treating the enlarged ID of the shaft which I either forgot or he forgot to mention to me!
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I had forgotten about that. Either it was the failure to grind out the drill marks from the inside of the shaft, or the failure to heat treat the shaft that caused the breakage. I probably forgot to tell you that.
Joe Gilbert and I just finished testing 35 different 10-6 props. (there are a lot more than 35 each 10-6 props) The Fox on the Twister didn't break a crank, so I must have done it right. It is amazing to find the in flight difference between 35 props!
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Hi De, When I received the most recent CLW issue, I read the article which you and Joe had worked up before I even looked at my own work! I found the work that you and he had done was most interesting! Indeed the difference between props is astounding! As for me I rarely have any need to use 10 X 6's any more but perhaps I should! Last June at Brodak's FlyIn Joe really kicked some serious butt! He deserved it nevertheless. It was great to see him and his wife having such a great time out here! I hear that you will be joining us this year. Here's hoping the rumors are true and that your schedule really does permit you to come on out east! John AShford surely did have a fine time last June as well. Elyn Aud and he drove out in John's then new to him convertible car.
Tally Ho!
Phil Spillman
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I see them both as roughly equal in capability, with the OS having the edge in smoothness, and fuel economy. If you have a older Fox, then you may have to fool with strap on mufflers, so the OS has an advantage here, too. By the way, I am referring to the OF FP, not the LA.
But I use them both in a typical flying session, one minute flying a Fox Stunt on, say, a Flite Streak, then an OS 25 on a Ringmaster, or perhaps a Carl Goldberg model. I might run a 10-4 or a 9-6 on the OS. The Fox may be either a 29 or a 35, and it could possibly be as old as a four bolter, with a two bolt backplate.
Currell
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If you want an engine that runs like a sewing machine, go with the OS. If on the other hand, you want an engine that makes glorious noises, and has a special charactor all its own, go with the Fox. I prefer the latter. Either can be made to work, and work well. Having said that, I run McCoy Redheads on most of my profiles. The other engine with charactor.
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I don't understand understand why some people are down on fox engines. I have several of them and I love every one of them. I have won Old Time stunt advanced at Brodak's two years in a row flying an El Diablo-Fox 3. The fox is unmodified stock right out of the box including the needle valve. It runs a beautiful 2-4-2 break. I consider it to be the perfect engine for this airplane. That being said I also have several os la 25's and I love them as well. The os's run smother and they have as much or more power than the fox but they don't have that wonderful 2-4-2 break
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The Tulsa Gluedobbers have a Triathalon Contest every Fourth of July. The Triathalon consists of Racing, Stunt, and Balloon Bust. The airplanes allowed are flapless profiles such as Ringmasters, Goldberg Shoestrings and Busters, etc. The engines allowed are unmodified plain bearing .35's with baffled pistons, and unmodified plain bearing schneurle ported .25's.
For some strange reason, the Fox .35's beat the OS .25 Fp's and LA's.
We see this every year.
Go figure.
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As Dirty Harry said, you've just gotta ask yourself one question: Do I feel lucky today? Well do ya' punk? If ya' do, then toss more than 50 years of technological advancement aside, get a Fox .35, and try to figure out how to get the fuel that it needs and how to get a decent run out of cranky old paint shaker. On the other hand, if like me you don't feel particularly lucky, get a modern control line engine. The OS .25 LA-S and Brodak .25 are two excellent choices for this size model. When you're enjoying flight after flight of consistent engine performance on readily available fuel, you aren't gonna care that you're not flying a Fox, K&B, Johnson, McCoy or any of the other control line classics that have gone the way of the Do Do. You'll even forget about the mythical 4/2 break that doesn't mean a thing as your engine reliably powers your model through the pattern in a nice steady 2 stroke. You'll simply chuckle to yourself at the end of each flying day safe and secure in the knowledge that you did the right thing baby.
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Chucky,
Why don't you come up to the Gluedobber's Triathalon next July 4th and show us how it's done?
Are you the same Chucky that was using my picture as an avatar over on SSW?
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Chucky,
Why don't you come up to the Gluedobber's Triathalon next July 4th and show us how it's done?
Hasn't a Fox 35 won it more than any of the other engines allowed S?P
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Sounds like someone who doesn't know enough to get a Fox to run well, and another thing--- I can still get parts for my 1950s,60s, 70s, 80, 90, and 2000 years fox engines. Can you say that for the OS s, STs, Enyas, OR ANY OTHER FOREIGN engine?? I currently have six OS FP25s and cannot get support parts and my LAs have plastic backplates that leak and remote NVAs that won't hold settings very good.
I'll take foxes.
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OS took the perfectly acceptable FP, and gave it a gimmick case/head, silly philips look-a-like screws, a plastic backplate, and a goofy remote nva. Even the punched steel prop washer is cheap compared to the earlier FP. So why would OS do this? To make more money? The target market for the LA's are the R/C throw away trainers, why build in any more quality then they need to? And when they come up with a new idea, the LA will be cast off and parts will dry up just like the FP. Meanwhile, Ft Smith keeps cranking out Fox 35's, offering support, and spare parts... Sure the Fox has it's quirks, but they can certainly be worked around, same as the LA.
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Put together a Super Clown Today and had bought a new LA.25 for it. Fitting the LA.25 to the Super Clown I had a change of heart and bolted up my rusty,trusty Castor oil burnt Fox.35. For some reason this just felt right, the way old Duke and Matt intended.
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Some feedback desired. Would on OS .25LA fly the same profile plane as the Fox .35? Both engines weigh almost the same and most of todays engines make a lot more power than the old Fox .35.
The LA will fly the smaller "35"-sized models like the Skyray 35, Ringmaster, etc, very nicely. The Fox will do better in larger, 400+ square inch models like the Twister, Nobler, etc.
We have had a lot of luck replacing Foxes with 20 and 25FPs, but the LA is not nearly as strong as even the 20FP and absolutely no match for the 25FP. The 25FP flies a Nobler or Twister just fine.
Brett
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No kidding? A Twister with a .25? My 'Twister' is slightly over sized and stretched and whatever. And I have an LA 46 on it! I just like the engine. Same bolt pattern as my old favorite, my trusty Tower 40s. Alas, I just like the 46. What a cool engine. 43 ounces, I think. Been awhile. May swap it with a Tower and an APC 10.5/4.5 this summer, but I really like the 46. Gonna have to get a spare before they go out of style. Don't laugh - they stopped making the Tower 40. Not before I bought a second one for $45... I have a hand made venturi and an ST NVA on it, but otherwise it are as came from the factory. As is the LA 46.
As to the Fox 35? No joke - I was given one. A black unit with gold plated screws and needle and such. Even the instructions tell you not to bother running it. Great. Intermediate at the 99 Nats? Forgot the guy's name, but I sent him a thank you note. Big on Orientals, if I recall. Can't recall his name for the life of me.
I have a sandcast two bolt on a Super Clown. That I take out for balloon bursts and such. Out of six or eight Fox units, it probably runs the best. Came in a box of 'CL' engines I paid $50 for from a guy at the local RC field. Heck, I think I got $50 for the two McCoy diesel .049s that were in that box. More than $50, maybe. Anyway. There was a sand cast two bolt backplate 35 with an Austin NVA. It seems to work okay. Perhaps it is worth more sitting in the file cabinet.
I like the modern stuff. Perhaps the Fox is as cool as a twin cylinder 360 degree crank British motorcycle with a kickstarter and an oil stain under it. But, my Tower units and my OS units start every time. One flip, maybe two... They just work. Nice guy that I am, don't even think about giving me a Fox 35. First, I'll kiss you and then I'll beat the daylights out of you with either a tire iron or a frying pan. Do they still make tire irons? My 68 Buick Special had one. It even had traction bars - from the factory. And I really don't want to kiss you for your Fox 35.
Sandra Bullock doesn't fly model airplanes, does she?
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You do need to know what you are doing to make a Fox run right. The most important item is the fit between the piston & cyllinder. I got very good at lapping the piston & cyllinder to avoid spending an hour or more bench running it. After lapping, I put 4 tanks thru it on the bench, then bolt it to a plane and go flying.
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I have a favorite Fox which I think is one of my best stunt engines. It started life as an L&J tuned engine and it ran great. When the Fox ceramic liner became available, I converted my L&J. I now have an engine that weighs less than 6 oz and puts out power comperable to a Brodak 40. I love the 4-2-4 break and this engine excels at it. The only downside is that it burns a lot of fuel - 3.5 oz for the OTS pattern. It runs as smoothly as a modern 25, turns a 10X6 RSM prop with authority, and runs on my standard blend fuel. For me, this would be the ultimate OTS Nobler engine. Mine is now in a light El Diablo and justs coasts thru the OTS pattern.
I also have a Feno with a Brodak 25, so I understand modern engine operation, but a really good Fox is still great fun.
Steve
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Sounds like someone who doesn't know enough to get a Fox to run well, and another thing--- I can still get parts for my 1950s,60s, 70s, 80, 90, and 2000 years fox engines. . . .
. . .
I'll take foxes.
Are prop choices clouding the issue? Is that part of what you meant by "know enough to get a Fox to run well . . ."? Nearly everyone who talks of the "magic" OS / LA 20 / 25 engines also specifies a specific APC (Brett Buck's "tune-up" for example).
Marvin, or anyone, how much difference does an APC 10 x 5 (my guess; 10 x 4, or ??) make on a Fox 35? Or vice versa -- an old Top Flite wood prop on an little OS or LA? The note above on prop testing didn't mention sizes or brands.
Reason I'm asking, we have a "club project" that will start with a Fox 35 U-Key, and I just automatically got some APC 10 x 4s and 10 x 5s because of my good experiences with APCs. An APC 10 x 6 seems like it might be a hefty load for the Fox -- and a 6 pitch prop seems to me like "too high a gear" for an efficient prop on a fairly small airplane. But what do I know? I haven't run a Fox 35 (on an airplane, anyway) since 1959 or thereabouts.
Larry Fulwider
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No kidding? A Twister with a .25? My 'Twister' is slightly over sized and stretched and whatever. And I have an LA 46 on it! I just like the engine. Same bolt pattern as my old favorite, my trusty Tower 40s. Alas, I just like the 46. What a cool engine. 43 ounces, I think. Been awhile. May swap it with a Tower and an APC 10.5/4.5 this summer, but I really like the 46. Gonna have to get a spare before they go out of style. Don't laugh - they stopped making the Tower 40. Not before I bought a second one for $45... I have a hand made venturi and an ST NVA on it, but otherwise it are as came from the factory. As is the LA 46.
That illustrates an interesting feature of low-pitch/high rpm - it doesn't matter (as much as it used to) how big the airplane you are dragging around might be, or what the engine size you use for a particular airplane. We've gone from OPS40s to PA75s in 630 square inch airplanes over the past 20 years, and the performance hasn't really changed that much. You can't do that with 6"-pitch prop engines, or at least it doesn't work very well - either you don't have enough power, or you have too much and can't control the speed.
Brett
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. . .
You can't do that with 6"-pitch prop engines, or at least it doesn't work very well - either you don't have enough power, or you have too much and can't control the speed.
Brett
Does that kind of answer my question (reply #29) also? The Fox 35 is a "6"-pitch prop engine" and an APC 10 x 5 would be running at too low of an RPM to "do the job"? In short, folks are still running 10 x 6s on Fox 35s because they have to? (doesn't sound right, but you get it)
Larry Fulwider
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Does that kind of answer my question (reply #29) also? The Fox 35 is a "6"-pitch prop engine" and an APC 10 x 5 would be running at too low of an RPM to "do the job"? In short, folks are still running 10 x 6s on Fox 35s because they have to? (doesn't sound right, but you get it)
Larry Fulwider
Larry,
Remember, not all "6" pitch props are the same pitch. There is a great article in Control Line World on props for a Fox on a Twister. The "best" prop was an RSM 10X6, but the APC 10X5 was close. It seems many APC props operate like they have more than the indicated pitch. You are correct in your initial concern that an APC 10X6 is a bit much prop for a Fox.
Steve
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Does that kind of answer my question (reply #29) also? The Fox 35 is a "6"-pitch prop engine" and an APC 10 x 5 would be running at too low of an RPM to "do the job"? In short, folks are still running 10 x 6s on Fox 35s because they have to? (doesn't sound right, but you get it)
Yes, I get it, and to a certain extent, you are right. A fox with 5" of "pitch" is on the edge. It will spin it fast enough to fly the airplane, but it doesn't have a lot of breathing room left. 6" of pitch puts it in the "zone" where it can pretty well loaf along in level flight and have something left for maneuvers. 4", forget it, won't come close. With a 25FP, you can spin a 9-4 or 10-4 fast enough to fly the airplane (maybe 12000 in the air) , and it's still got plenty of room to rev up more. And I have tried this experiment more than a few times - same prop (Rev-Up 10-4), same airplane (Skyray 35) and switching engines between the 20FP and the Fox. Match the level flight speeds. To comparison. Both cases were vastly better than the Fox with a 10-6, but the 20 was much better than either, not even close. Not to mention that the Fox self-destructed and damaged the nose of the airplane from vibration, in just a few flights.
That's also why something like an APC works so much better than, say, a Rev-Up of the same dimensions on the 20/25FP. The APC takes very little to spin it at 12000 RPM, so the engine is not laboring so much. With a Rev Up, it will do it, but you have to run it much harder.
It's not particularly unique to the Fox, either. A typical prop for an ST46 was a 11.5-6 or 12-6 rev-up. It had no problem getting a 11.5-4 up to launch revs, and would match speeds with the 11.5-6 in level flight. But it was totally gutless in the maneuvers. It didn't even work with an ST60, same problem, even though you had 1/3 more displacement still. Take the same prop, put it on a 40VF in essentially the same airplane, and you get 6 National Championships and the current "Gold Standard" of stunt power. The only real degree of freedom you had in improving performance was adding diameter, which is what everybody did. It wasn't like people in 1970 didn't know what they were doing or couldn't figure out what was going on - Wild Bill was talking about pitch in the 50's. But the engines weren't there to make it work, the way to improve the run was to run more diameter, you needed all the power you could get (since it was never enough), and so you used your 6" of pitch, and run the biggest prop you could manage.
Some still haven't grasped that things are different - but I note that David went from a 51 to a 61 to a 65 and now a 75 and is using more-or-less the same prop.
The real breakthrough with current propulsion is low pitch. "Schneurle Wars" engines from the late 70's/Early 80's had enough poop to make it work, for those who clued in, but tended to be difficult to control. Adding the pipe just made them controllable.
Brett
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I've got a 20FP on my Twister, and I had a 25FP on a Nobler ARF for awhile. Both were good matches. The Twister actually had a 35FP and a 40LA at one point, and neither matched as well as the 20. The excess power was wasted on a light plane.
I don't think the key to the Fox 35 is a magic bullet prop. It's not a fancy aftermarket modification, a bypass plug, or a $100 rework. The key to the Fox 35 is a ton of run time. I've got several Fox 35s that start on the first or second flip, same as my OS engines. Some of them are built from salvaged junk parts, some are bone stock, some are name brand reworks. It doesn't matter they're still just Fox 35s and the more they've been run the better they usually run. Most people buy a new Fox 35, run it a few times on the bench, and put it in a plane expecting it to run perfectly the first trip out. Sadly that Fox isn't going to develop into a really good engine till it's been run 50-100 flights. The easiest shortcut I know of is to buy a well used engine. I've got at least half a dozen new in box Fox 35s and I wouldn't even think about breaking one in for a new plane.
I haven't found one prop that always works perfectly for every plane with a Fox 35. The APC 10x5 lets the engine run in the classic 4-2-4 break, but it didn't work well on my Ringmaster. I ran a Rev Up 10x6EW, an old Top Flite 10x6, and finally settled on a Zinger 10x6W. On other planes I've had good luck with the black plastic Master Airscrew 10x6. All of the above worked OK. Some planes respond to different props, it's best to try a few and record the changes. Go with whichever works best for your application.
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I don't think the key to the Fox 35 is a magic bullet prop. It's not a fancy aftermarket modification, a bypass plug, or a $100 rework. The key to the Fox 35 is a ton of run time. I've got several Fox 35s that start on the first or second flip, same as my OS engines. Some of them are built from salvaged junk parts, some are bone stock, some are name brand reworks. It doesn't matter they're still just Fox 35s and the more they've been run the better they usually run. Most people buy a new Fox 35, run it a few times on the bench, and put it in a plane expecting it to run perfectly the first trip out. Sadly that Fox isn't going to develop into a really good engine till it's been run 50-100 flights. The easiest shortcut I know of is to buy a well used engine. I've got at least half a dozen new in box Fox 35s and I wouldn't even think about breaking one in for a new plane.
Absolutely! I have as many full-pattern Fox flights as most people, and getting it broken in, and particularly, getting the front end loosened up, is key.
Just because I know that there are 100 people picking up the poison pen to complain about "Fox-haters", there are some very good reasons the Fox won all those contests. In a full-fuse airplane, it's as good as any other 4-2 break motors, and is dead-nuts repeatable. It's decently powerful compared to its compatriots, too. Not too bad for a 60-year-old engine design. It has its bad points but in the right place and run like it wants to run, there's absolutely nothing wrong with it. That there happens to be things that are far better doesn't change that.
Brett
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Just to add a little proof is in the puddin here, Andrew has a Fox 35 on a Ringmaster that runs so sweet it will make tears come to your eyes. Andrew seems to find these old beater Foxes on E-bay for cheap that have about the right run time on them to simply run really really good.
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Dan Banjok has a great running 60th anniversary. Fantastic. Powerful. He lapped in the piston (after replacing the original out of round cylinder), machined and installed a new front bushing (it was binding and off center), cut a groove in the back plate to install an o-ring (it was leaking), and...
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Dan Banjok has a great running 60th anniversary. Fantastic. Powerful. He lapped in the piston (after replacing the original out of round cylinder), machined and installed a new front bushing (it was binding and off center), cut a groove in the back plate to install an o-ring (it was leaking), and...
Dennis: That's a new one on me. I have serious doubts that many Fox .35's are this way.
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Dennis; I have bought quite a few engines from Fox over the years and have never had any of the problems you related. If Dan had just sent the engine back to Fox they would have taken care of it no charge. They have the best service and warranty you will find anywhere. I broke a crank in one of my Fox 35's after about 3 years of flying, and they replaced it no charge. You just can't beat that.
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The quality's not there at the moment. True story. A new Fox. Other club members have sent engines back with only so so luck. In this particular engine the muffler bolt holes were also drilled at a slightly different distance than past muffler Foxes. Our club members have had difficulties with piston/cylinder fit. They were fit too tight. At times the cylinders were also out of round. Lapping will not solve an out of round issue. Dan got in the habit of lapping the pistons in, after a Fox came back from Fox with the same tight cylinder/piston problem. Lapping works if you have the feel for it and the patience to fit, put in a test run, refit etc. That can produce some fine running Foxes. The bushing issue was new. Dan probably took it as a challenge. So he machined a new bushing, removed the old one, and installed the new one.
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Many, many, many years ago when I played with combat, I had a combat special I stuffed into a concrete strip at the old City Park Circle in KCK. Sent the engine to Fox expecting to have to pay for a whole lot of parts. Less than two weeks I had a brand new combat special in my hads and no charges. I even told them what had happened. Have almost always had good luck with Fox. Had one carrier special that was sent back twice. To me the OS LA engines are throw away engines when worn out. DOC Holliday
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The quality's not there at the moment. True story. A new Fox. Other club members have sent engines back with only so so luck. In this particular engine the muffler bolt holes were also drilled at a slightly different distance than past muffler Foxes. Our club members have had difficulties with piston/cylinder fit. They were fit too tight. At times the cylinders were also out of round. Lapping will not solve an out of round issue. Dan got in the habit of lapping the pistons in, after a Fox came back from Fox with the same tight cylinder/piston problem. Lapping works if you have the feel for it and the patience to fit, put in a test run, refit etc. That can produce some fine running Foxes. The bushing issue was new. Dan probably took it as a challenge. So he machined a new bushing, removed the old one, and installed the new one.
Dennis:
How many NEW Fox .35's is your club having trouble with? Have you called the Factory to let them know of the problem's?
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De Hill,
Most of the Foxes we run, and there are many, are old Foxes. New Foxes are a novelty in our club. Since so many of the old engines are around. Two were recently purchased. Both needed piston lapping. Dan's needed the work I described above. Two other Foxes were purchased a few years back, new, by another member. They both had insufficient piston clearance, overheating during flight. Different fuels were tried. Engines were broken in on a stand at least half an hour. They were sent back to Fox, still had the problem when they came back. Dan wound up lapping those engines in. Problem solved. Setting up Foxes with tight piston clearance, just not the way to go. The unbushed rod takes a beating during break-in.
Duke is gone, so is his wife. Something is amiss. Sure it's possible to keep sending the engines to Fox, perhaps a working quality engine will be returned. But as it is, we've encountered problems. I'm passing the experiences on.
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Dennis Moritz,
As far as I can tell TWO new Fox .35's have been purchased in your club. Dan's had major problems, and the other new one was tight and had to be lapped.
Neither of the Foxes was sent back to the factory. This would have let the Fox Folks know that they were having problems. If problems are found with any engine the manufacturer should be notified. If you want to put it on the internet, fine, BUT the manufacturer should also be notified.
I don't see how including two old Foxes to your post bolsters your claim that something is currently amiss at Fox. The factory used to produce engines that were set up tight on purpose. Some guys will still order new Foxes set up tight. They feel after break in the piston/cylinder fit is better.
The Fox folks go out of their way to resolve problems with their engines.
Do you run any Fox .35's yourself?
De Hill
De Hill,
Most of the Foxes we run, and there are many, are old Foxes. New Foxes are a novelty in our club. Since so many of the old engines are around. Two were recently purchased. Both needed piston lapping. Dan's needed the work I described above. Two other Foxes were purchased a few years back, new, by another member. They both had insufficient piston clearance, overheating during flight. Different fuels were tried. Engines were broken in on a stand at least half an hour. They were sent back to Fox, still had the problem when they came back. Dan wound up lapping those engines in. Problem solved. Setting up Foxes with tight piston clearance, just not the way to go. The unbushed rod takes a beating during break-in.
Duke is gone, so is his wife. Something is amiss. Sure it's possible to keep sending the engines to Fox, perhaps a working quality engine will be returned. But as it is, we've encountered problems. I'm passing the experiences on.
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I'd like to step in with some comments about the Fox 35.
I really like the engines. I have many of them (I think the multiply on their own!) and at present, two are in flyable aircraft. Both were found at swap meets, old versions but new-in-box.
My 32 ounce Stinger has one of the early versions with fore-and-aft muffler lugs. It is 100% stock right down to the needle valve which is a bit touchy but I can work around it. It is side mounted, has a tongue muffler, uses a standard Fox plug and turns a 9 1/2-6 APC. 3 1/2 ounces of fuel is more than enough for the OTS pattern. It required around one half hour for break-in. It runs flawlessly in a fast two cycle and does not burp. The tank is a single vent non uniflow setup. Brodak 10-23 fuel exclusively.
My Nobler has a late 50s non-muffler model. I fabricated a simple band clamp in order to use a tongue muffler. It is stock except for the addition of one head shim and an ENYA NVA. I just could not get decent runs with the Fox NVA. I turned the ENYA spray bar down to .126" and all the problems went away. It also uses a standard Fox plug, a 10-6 APC and needs just over 3 1/2 ounces for the AMA pattern. Tank setup identical to the Stinger. Same fuel also. It runs in a very good 4-2-4 style with plenty of power to pull the 44 ounce plane. Although the piston/cylinder fit was not excessively tight (about the same as the Stinger engine), the Nobler engine required nearly 2 hours of run time before it would run acceptably.
For what it's worth - I really like the Fox 35. Properly set up and run it, it can still hold its own.
Many have had great results with various modifications but since mine serve me well in stock or nearly stock form, I prefer to keep them that way.
In quite a few instances, people have asked my what kinds of mods I've done, especially to the Stinger - they're more than a bit surprised to hear that the Fox is completely stock.
My two cents,
Bob Z.
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Ahhh, a good old Fox fight! #^
Reminds me of the good "old" days on Isky's CL forum.
Much more fun than a BOM fight!
So for me, a Fox is what puts hair on your chest.
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4 Foxes. Dennis Truxal had 2 purchased a number of years ago. They were sent back to the factory at that time because of over tight piston/cylinder clearance, they came back and still had the problem. Those engines were the first two I described. Broken in on the bench. Run with different fuels. Overheated in flight. Dan wound up lapping the pistons on those two engines. They ran well after that. The last 2 Foxes were purchased in 2008. On one engine, Dan replaced the the cylinder liner (out of round), lapped the piston, machined a new front bushing and grooved and o-ringed a sloppily fit back plate. The other engine seemed o.k. after the piston was lapped in. Like Boby Z says, our club has run a lot of Foxes. Dan has boxes full of them. Nevertheless it seems to me that the present day Fox factory would do well to improve quality control. I own 20 plus OS engines. None of those required TLC before they were run a few time on the ground, put in a plane, and flown. In Philly we laugh about the current Fox engine kits. But that's because we have skilled folks who can fix them. Imagine the frustration of an average modeler without back up. DT was definitely a frustrated and dissatisfied customer until DB lapped in his engines. Many of us in Philly enjoy Foxes, use them often, appreciate their run qualities. But the new Fox engines have been problematic, at least that has been true of the 4 engines bought new by club members in the last three years.
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I'm a bit confused. Would you rather Fox sent engines out with loose fits? A too tight Fox can be lapped, or run in, and will become looser as it's used. A too loose Fox is junk, and will require new parts to correct. From my experience it's not unusual for a never run Fox 35 to be so tight it can hardly be turned over with a prop. It's not a big problem, they loosen up considerably on the first few runs, and after a year or so of regular weekly use they develop into good engines. I would have to say it's normal, and not anything to be concerned about. If Duke were still around he'd probably suggest Lustrox powder. ;D
I can't say much about current production Fox 35s. I haven't bought one new since the mid 90s, and the last couple are still NIB cause I know I don't have time to wear one in correctly. But it seems silly to complain about an engine that was designed in the 40s because it doesn't meet the standards 60 years later. Compared to the other engines that were available in the 50's, the Fox is vastly superior. As far as the company, they've done more then most to support C/L. The only effort OS has made to support C/L, is to produce converted R/C engines. While Fox has made efforts to improve their product, and have adopted new technology (stuffer backplates, hemi heads, ABC and plasma piston/cylinder sets, new nvas, etc), OS keeps dumbing their product down. I haven't seen OS make a single change to improve their product, only changes to make it cheaper to produce and more trendy.
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The issue is quality control, not design. A year or so of running in... Why go through that. What's the point of those factory specs. A sloppy front bushing is a sloppy front bushing. Toss the part. Manufacturing tolerances were all over the place, in the new engines. Actually, I appreciate OS simplifying their engines, it allows them to manufacture product in Japan for a competitive price, instead of switching production to China. Manufacturing standards in Japan are generally superior to those in China. The simplified LA Engines run well in CL configuration, even tho swapping a through the venturi needle is a good idea. As well as sealing up the plastic back plate. As far as the new Fox control line engines, the ceramic pistons engines, the 60s, well, where are they? Cost too much. Aren't readily available. In any case, the so so quality of manufacture, if that is still a problem, would tend to negate any advantage of an innovative design.
Yeah. Lustrox. I've overheard Danny and Larry Scarinzi wax poetic and nostalgic about Lustrox. I remember those adds, also.
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The LA will fly the smaller "35"-sized models like the Skyray 35, Ringmaster, etc, very nicely. The Fox will do better in larger, 400+ square inch models like the Twister, Nobler, etc.
We have had a lot of luck replacing Foxes with 20 and 25FPs, but the LA is not nearly as strong as even the 20FP and absolutely no match for the 25FP. The 25FP flies a Nobler or Twister just fine.
Brett
I will say this one more time the FP- 20 is not stronger than the 25 LA!
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I will say this one more time the FP- 20 is not stronger than the 25 LA!
I have flown ARF Flite Streaks back-to-back, one fitted with a 20FP (BB T-U, of course), the other with a stocker 25LA. The 20 was used with an APC 9-4; we tried the 25 with both APC 9-4s and 10-4s.
The 20 was the stronger engine, although not by a lot. And the 20 delivered a better run; much like a piped engine.
I have not done any static testing, measuring the revs each will deliver with the above props. Mostly because I have found ground testing with various props better at determining how a test stand might fly than how the actual model will fly.
Dan
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I have flown ARF Flite Streaks back-to-back, one fitted with a 20FP (BB T-U, of course), the other with a stocker 25LA. The 20 was used with an APC 9-4; we tried the 25 with both APC 9-4s and 10-4s.
The 20 was the stronger engine, although not by a lot. And the 20 delivered a better run; much like a piped engine.
It's closer with a 10-4 than with a 9-4. The limitation I found with the 25LA was that at flight revs on a 9-4, it didn't have as much breathing room left for the maneuvers. It needed to be much closer to "gutted out" than the 20. I thought the 25LA worked best with 5" of pitch to reduce the revs so it has something left in level flight. But it was less effective overall because the pitch went up.
The 25FP is significantly stronger than both of them, but for whatever reason, it doesn't seem to draw fuel as well a the 20 with the same venturi. Frequently you have to choke it down with a fine air filter, a ST spraybar, or something like that, at which point most of the power advantage goes away. It also doesn't regulate as well as the 20, even with the same muffler. It's like it has enough more power that it overcomes the rather weak tuning effect.
The 25LA does have one significant advantage - you can still buy one!
Brett
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The 25LA does have one significant advantage - you can still buy one!
For now... But who can tell when OS will discontinue a product?
Dennis, We go through the long break in and even longer wear in process, to reach the Fox experience. The Fox still does what not many other engines can. It's a different experience, that's worth the trouble to some of us. If you want an engine that meets modern standards, then buy a modern engine. The Fox is an antique design, and to be brought up to the same standards it'd probably have to be redesigned. Assuming they could pull it off, they'd defeat the purpose of the engine to begin with. The Fox niche is that it's a currently produced antique, without that it's just not the same. Consider it a reproduction engine, with a few tweaks to make it more user friendly in a modern world. It works as well now as it ever did, and is likely built to the same or better quality control standards. That expectations have changed isn't really to say that Fox has suddenly developed a quality control problem. The world has changed, Fox has stayed the same.
Back to the "new Fox control line engines", I was talking about upgrades that have been made available for the Fox 35. The point being that Fox has continually updated an antique, supporting C/L. No one else has done this. But I'm glad you brought up the new 60 since it's an even better example of how Fox has made efforts to produce new C/L products. Granted it seems they were a bit misguided. Developing an engine for a market that doesn't exist, and then trying to sell it by telling us it ripped the wings off the flying test stand, pricing it too high, etc... It's still more then most other manufacturers have done. I don't see OS re-releasing the 40VF for C/L stunt.
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De Hill and Andrew,
I just got off the phone with Dan Banjok. Checking information against what I remember. Actually I'm wrong about the specifics of the 2 new 60th anniversary engines. One was fine. Jack Weston broke his in a bit. Since then it's been running well on an Old Time plane. Dan's engine needed the rework that I described. That engine was sent back to Fox when Dan discovered that the bushing/crank fit was too loose (leaking fuel), the cylinder clearance too tight, etc. Fox sent the engine back without rectifying anything, at least that's how it appeared to Dan. Dan then went to work, machining a new bushing, lapping the piston, grooving the back plate, installing an o-ring and so forth. The back plate was acceptable as is, a typical Fox piece, Dan just figured it would be neat to have plate the fit perfectly. The machining also let him set the crankpin to back plate at a distance he thought optimum. The cylinder was out of round, but was o.k. (not replaced) after the piston was lapped in to fit. Dennis Truxal had 2 engines, at least as far as I remember, Dan only remembers one. See above.
The problem with cylinder/piston fit seems to date back to the 40th anniversary engines, when Fox introduced a cylinder taper, pinching the piston at the top of the stroke. Dan says that problems occur when the taper is a tad too steep, causing piston bind right above the exhaust port. Running in takes a long time, if that happens. Causing excessive wear to the rod. Dan discovered this issue when running in a new 40th that would not top 9000 revs with 9x6 after a half hour break in on the bench. After careful lapping the engine came into it's own. Running with a lot of power. Dan's new 60th is a very strong runner now, with a strong break, lots of power. The pre-40th engines are made with a straight cylinder wall. Those engines break in without much issue, but are poor at hot starting. Tapered sleeve engines probably make a bit more maximum power.
Yep, Foxes have their fascination.
FPs and LAs can be adopted to our needs and made to work well. Longevity is rarely an issue. Easy enough for those of us past 60, to lay in a lifetime supply. Comparatively cheap, too. Beyond that, of course, are the dedicated stunt engines. Amazing products. Durable, tunable and manageable, etc. Great, great products. Dan's PA61 was in steady use for five seasons. Still runs great. I doubt that the Fox 60 would compare. At nearly $300, if you can get one, well, that's near PA/Ro-jett territory.
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Uhh Dennis,
Does this mean you were wrong about Fox .35 reliability?
De Hill
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It's not reliability De Hill. It's quality control. Dan's engine was a mess. Sending it back to Momma Fox didn't help. Dennis' needed to be lapped. Period. Running an engine in for a season. No. Not good. Actually, the Foxes can be amazingly durable when the parts are harmonized. I'm sure you know that. I've seen many run year after year. Abused and run hard. We in Philly can make them scream. Amusing old buggers. Like the folks who cherish their eccentric ways. (And history.) Lots of Philly Fliers are into them. It's taken me years to get my FPs and LAs to behave. Even with the wise generous council of the knowledgeable and skilled. On to Foxes? Mebbe. I have a few. There's a Ringmaster somewhere in my future, I'm sure. Nearly everyone in the club has one. Usually ugly beasts, crashed and crashed again. Contest winners nevertheless. I'd like to build a purty and light Ringer. Probably a bad idea for aFox 35 paint shaker. So what. Boldness. Boldness counts.
Best,
Dennis Moritz
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One thing I do when I get a new Fox 35 is remove the plug, and turn the engine over to feel the tightness in the cyl. I then loosen and tighten the head bolts till I get the least amount of drag when turning the engine over. Sometimes it only takes a 1/16 of a turn on one bolt to really reduce the tightness in the cyl. This really speeds up the breakin and only takes a few minutes. I do this on FP40's also as it is very easy to warp the cyl on them also. I did have one 50th anniversary model that did have a wet nose, even thou the bushing was not loose. After a call to Marvin Denny I removed the shaft and finished cleaning out the groove in the bushing that was slightly plugged at the rear. That took care of that and it never leaked out the front after that. I have some Fox 35's that have very loose front bearings, ( the best running ones btw ) that still don't leak out the front as long as the groove is clean.
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My Fox, and my Ringmaster; they comfort me. #^
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De Hill, that is a funny line! H^^ Thanx.
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You can't really go wrong with a Ringmaster and a Fox 35. Mine is scratch built. I cloned the original kit with decent wood, a spruce spar, and real plywood. At 26oz it does the job. It'd probably fly better with a OS 15FP, but then all the ambiance would go right out the window.
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I hear all of the defense lines about the Fox units - but I've never had to speak to Japan or China.
Keep hanging on to it, but guy in the mini van next to you ahs a six disc CD, a navigation system, adjustable brake and throttle, heated seats, and more cub holders than even grandma would need.
Doesn't have any Fox logos anywhere.
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Clayton,
I don't care if anyone else runs Foxes.
I enjoy them.
(and pacific rim engines also)
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According to my handy engine inventory list, I currently have 10 more OS engines then I do Fox engines. Added together those two brands make up 2/3rds of my available engine stockpile. Both brands have their place. It's like having the fully loaded, luxury car to drive everyday, and an impractical, uncomfortable, classic car to drive on weekends. Sure a person could take that minivan to work or the grocery store, but the guy that takes his vintage muscle car is probably going to have more fun.
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I am afraid to count how many engines I have. I know of one that is still brand new in the box. When I started it was with an OK Cub .049A. Then Cox Babe Bee. From there it has grown to McCoy's, Fox's, Johnson's, K&B's, Super Tigre, OS and O&R ignition that I need to get running. I know almost all the planes have engines on them, I think about 30 planes. Have fun, DOC Holliday