iskandar taib

My Feedback: (5)

So we're supposed to list the Fox engines we have? Mine are mainly Fox Combat Specials - 2 or 3 Mark IVs, a Mark VI and a Mark VII. Won the Mark VI at a contest (Duke Fox Memorial), bought the Mark VII off Howard Rush. Unfortunately it ate a circlip, is in parts.

Also have a NIB Fox Stunt, a .25BB, two or three .15BBs and one .15 Schneurle PB that belonged to Marvin Denny.

Iskandar

earlwb

You have a nice collection of Fox engines there Iskandar.

BtnFlyGuy

Which Control Line FOXis this? It's about the size of a .35 stunt but feels heftier. No markings on the bypass side except the word "FOX". slant plug. Thanks!

Cougar429

My Feedback: (3)

I have to regretfully report the modified 50BB was yanked from the Seamaster. I had serious surging problems that any amount of work would not cure. Several near misses getting the plane back to the field had me thinking I was pushing my luck too far. What was weird was this problem was not repeatable on the ground. Only occured in flight. Since the OS 55AX fit the same mount it was an easy installation, (albeit requiring a throttle extension).

However, the surge remained. I finally tracked it down to an extremely flexible pickup line I installed in the tank. Guess anything over 1/2 throttle on either engine produced enough exhaust pressure to collapse the line. Replacing it with standard silicone solved the issue and I have now had several trouble free flights on the uncowled motor.

Due to the fact the new F/S cowl is already fit to the OS, (old plastic cowl was showing effects of age and heat) the Fox will stay in storage until I find a good home. In fact, when the weather prevents regular flying it may get stuffed in the nose of the Harvard II in place of the EVO 46. That thing is already transonic on a 2-blade. Just hoping I would get better performance out of the more scale 3-blade. What should be interesting is the Macs pipe will now bolt to the engine.

On another subject, still waiting to build the adapter to fit the new muffler to the Eagle 61. Will post pics when complete.

1QwkSport2.5r

I asked around awhile back and never got any hits so I'm going to ask around again... I have a 1983 Fox .40 series 5 engine (single rear BB, bushed front end) that I originally thought the glow plug element disappeared and got stuck between the piston and liner but it turns out the engine crapped one of the "G" wristpin clips and thats what got stuck between the liner and piston. I found a piece of it about 3mm long stuck to the liner.

Anyone have an old piston and liner set in decent shape that would fit this engine laying around that nobody wants? I'd love to get this thing running again, but if I cant track parts down I'll hold onto it and send it to fox and get another new engine. I wonder if the piston and liner from the current fox .40's would fit...

Anyway, if anyone has any info or parts let me know.

carddfann

Got a Fox Hawk 60 question for you guys. I recently bought one that seems to still be new or almost new, but no box. There's one thing that seems odd about it. The crankcase doesn't have chrome plating. I'm sure its a Hawk crankcase with the 3 mounting holes per side and the rear cover says Fox Hawk. Its in great shape, but does anyone know about the lack of chrome on the crankcase? Does it have any significance regarding its history? Maybe its one that made it thru the Fox plant without being plated? Just wondering if anyone would know.

controlliner

Fox engines Never had chrome plated crank cases, they were tumble polished. Later Hawks were glass bead blasted.

carddfann

Didn't know that. This case doesn't look like it had any polishing. It looks sort of raw and kind of gray, yet the rear cover is polished and shiny along wih the carb so it makes the case stand out. This something I wouldn't know since my Foxes are all newer except for an old .15.

earlwb

yes the Fox Hawk .60's first came out with polished shiny crankcases, later Fox decided to bead blast them to give them a somewhat darker flat finish. I think it was a effort to make them look more like the OS engines looked at the time.

carddfann

Huh, so it is significant regarding time frame. So I got one of their later Hawks. I just thought it looked strange with all the other parts black, red, and polished shiny. I was starting to wonder if I got a factory error or maybe it was rebuilt, but it looks new to me. Compression is very strong with smooth bearings. Thanks!

iskandar taib

My Feedback: (5)

How about a picture of the other side?

It might be one of the older .36Xs, of which there were several types. The later Combat Specials (Mark III onwards) had the "tall rear door" and square intake. Baffle piston?

Iskandar

earlwb

It looks like Fox .35, but it could be a .29 though. They use the same crankcase. But usually it has a .29 stamped on the mounting lug.
Now Fox did make some .36 RC engines, but I don't think he made .36 stunt engines with them also.
If it is slightly smaller than a .35, it could be a Fox .25 or even a .19.

Sport_Pilot

I think that is a Fox .36.  It is not a stunt engine, nor a high performance engine.  More powerfull than a stunt though.  Meant for Sport and Scale control line flying. 

BtnFlyGuy

Thanks guys. It's a 36. It's not supposed to have the 2/4 break like a stunt.35 is it?

earlwb

I think if you have a muffler on it and you are running muffler pressure, there is no 2x4x2 break in a control line plane. But without the muffler pressure it would have one. They used the same needle valve assembly as the other control line engines.

i looked back and found some Fox instructions for a 29, 36, 29RC and 36RC engine so they did make some as a CL engine. I just do not remember ever seeing any before.

Sport_Pilot

No. The 4-2-4 break is a function of the port timing, especially the exhaust with early blow down. The needle valve doen't affect this at all. The Fox .35 stunt even has minimal fin cooling area because it doesn't need it. Run it on lower castor fuel and without four cycling and they will over heat. The .36 has plenty of fin area and will run fine on 20% castor fuel, though 22% would be a mite bit better.

Stunt engines still do 4-2-4 breaks with mufflers, but not withmuffler pressure.

controlliner

It is the .36 Sport. If you run it without the intake restrictor, it will scream like a girl at a horror movie.

Broken Wings

My Feedback: (20)

Which one is it? Sport, Delux or Std....

I swapped one of my club mates for this Fox .40... They all look the same on the Fox Web Site.

What are the differences?

hsukaria

I don't know, but it looks older than dirt.

Broken Wings

My Feedback: (20)

Yep....

earlwb

That is a Deluxe engine. It has the integral spinner prop washer backplate on it. the standard engines don't have it.
By integrating the spinner backplate and prop washer into one unit, then you don't have to deal with the fact that the prop shaft can sometimes be too short when you bolt on a prop and separate spinner.

Broken Wings

My Feedback: (20)

Thanks Earl... It's got good POP! It may need a new set of bearings. There's a piece of fuel tubing on the needle valve, I guess it may have been leaking. I've got a Gallon of Sig Champion all castor to run through it.

earlwb

It probably doesn't need the fuel tubing as it has dual tabs for holding the needle valve so it is centered better. But the tubing won't hurt anything either.
interestingly enough instead of sucking air, the needle valve tends to dribble fuel out of it instead. The muffler pressure is enough to cause enough positive pressure to cause the fuel to flow out and not suck air in. If you watch some of the engines real close (don't get too close or you get stuff in your eyes) you'll see it dribble a little out of the needle valve. The threaded portion of the needle is on the outside so it gets positive pressure from the fuel tank's muffler pressure system. The needle tip though is on the inside where the carb venturi has a low pressure (vacuum) so it sucks the fuel into the engine. You can see this effect with other brand engines and not just Fox engines either.

Broken Wings

My Feedback: (20)

Would you happen to know what the bearing numbers are for the forty?

earlwb

I think it is the R6N-ZZ and R8. You can remove the shields and seals if they bearings have them as the Fox engine doesn't use sealed bearings.
The Boca search comes up with this: http://www.bocabearings.com/search.a...LLECT&Feature=

The Fox part numbers are 13842 for the rear bearing and 26043 for the front bearing.