Hobbsy

My Feedback: (102)

I am opposite of that I would just thnk that they were just happy customers like me.

Konrad

Guys,
The thread title is Fox not bearing vendors! Now if one wants to discuss bearing materials and bearing race geometries that might be on topic. In fact it might help some of us understand what makes a bearing suitable for our application, the Fox engine. But a discussion of vendors is rather off topic!

I'm surprised the moderators have let this discussion go as far as it has. Heck they slammed me for discussing Fox model hardware!

Please keep to the topic FOX.

All the best,

Konrad

w8ye

My Feedback: (16)

It is no secret that Boca offers sponserships. It says so right on the web site.

hsukaria

Hey everybody! I just received a used Fox 74 Eagle 4 I bought used from RCU, in great shape. I have not used a Fox engine ever before (except in 1977 with a Fox 25 that others set up for me) and have a few questions:
1. What fuel to use? I usually run 15% nitro, and Synthetic/Castor blend (Rich's Brew). I've read a few posts here and get the impression that I need less nitro and more castor?
2. Itt came with a tilt-up muffler, but would like to get a Pitts style, anybody make those? Otherwise, I will need a tilt-down muffler.
3. What is a good size prop? 13x6? The plane I will put is on can't go larger than 13" diameter. Maybe a 12" preferably.
4. Where can I find an owner's manual for this engine? Any online copies? Or get it from Fox directly?
5. I suspect this engine has an air-bleed carb? I see a screw lining up with a small hole in the front of the carb. Is that the preferred carb, or should I skip it and go to a 2-needle carb?

Thanks in advance.
Husein

earlwb

Use 5% nitro or even 0% nitro glow fuel. You need at least some castor oil in the fuel, do not use 100% synthetic oil fuel.
The engines have fairly high compresion and do not like higher nitro percentage fuel. You may want to run a 11x8 prop for a while at first to get used to the engine. Then try a 12x6 and see how that goes. It ought to pull a 13x6 but you'll have to break it in good first. You might even have to put in a extra head gasket or two on it to lower the compression to run a 13x6.

Hobbsy

My Feedback: (102)

H, that is a fine carb, it is a metered carb with an airbleed trim. Do as Earl says on the fuel, it will turn a 12x8 Graupner at 11,200 rpm on 5% fuel with 20% castor. Set the airbleed screw halfway across the inlet hole to start, it will require very little if any change from there.

hsukaria

Since it is a used engine, I am not sure how much break-in it has. Should it be all castor, or can it be a blend like 15% synthetic and 5% castor? I get the part for 0-5% nitro and smaller prop, 12x6 is fine for me.

I will call Fox about the muffler, I would like a Pitt-style if available anywhere.

badger5964

My Feedback: (6)

JTEC sells a bolt on Pitts style. I run mine with one tube plugged.

[link=http://www.jtecrc.com]JTEC RC[/link]

fujiman

My Feedback: (133)

if eng is cranky on fuel with greater than 5% nitro. then opt. for the latest head button from fox and add extra head shim (2 total) with newest head button and extra shim, 10- 15% nit. is poss. this eng has some real grunt so when broken in it will turn a 12/7 prop like gang busters.

earlwb

Yes a fuel with a blend of synthetic and castor oil is fine.
Even on a used engine, assume it is not broken in. With ther big 60's and 74 engines from FOX many people had trouble with them and gave up. usually it was running too high of a nitro percentage fuel without lowering the compression or for some odd reason they couldn't figure out how to adjust the carb, or they didn't have the patience to break it in good.

fmichaelb

Here is a link to the owner's manual

http://web.archive.org/web/200609011...s/eag4man.html

hsukaria

Thanks for the info. I will try running it with the lower nitro and with castor oil content first, then make any of the modifications mentioned if it seems necessary after running it for a while.

fujiman

My Feedback: (133)

excellant plan of attack!!!!!!!!!

Cougar429

My Feedback: (3)

I had a boo through the info on Fliteline Solutions and found the mods on the 50BB particularly interesting. One thing that stuck was the tendency for detonation to sound like an airframe rattle in flite. I run 15/20 Rich's Brew and am at 660' ASL. Don't notice anything setting the motor on the ground, but with that loud exhaust I may be missing it.

Unfortunately, the pertinent pics on the profile changes for the head mods don't come up. Anyone have that information? I have access to the tooling.

p.s. there was also notes on the 40 I was having fun with, so have printed all of it for future reference. The new case should arrive any day and I can address the points when transferring everything over.

50+AirYears

This isn't RC, but it is about Fox engines, and for some reason, I haven't recieved updates for a couple months, so I'll just put in this little blurb, and recheck the box for updates. I was recently gifted with a Top Flite ARF Flite Streak. Went onto a controline forum with some questions about it. Put down a list of engines I have available for it, including the fact that I have a BB Fox .25 cl engine. Got advised not to use any of my .35s or .36s on it because the fuse is a built up sandwich, and the engine mount area is a little soft. The general recomendation was to get an OS LA .25 CL engine. Concensus was that the Fox .25 might be too much engine. Believe that? Guess I'll follow some recomedations to reinforce the fuse, or maybe build up a new fuse from 1/2" balsa and good birch ply and maple beams, and see how the ARF compare to my old kit built FS with the old .36X.

w8ye

My Feedback: (16)

I had a lot of Flite Streaks in the good old days. They all had 35's on them and there were no problems because there was a 35 on them.

NM2K

My Feedback: (14)

I'd put it online and sell it. Who needs a P.O.S. like that? When you buy a Flite Streak, you expect it to be flight worthy with the same engines that the original kit built examples could utilize. They only take an evening to build from scratch anyway, if you are adept at CA glueing and holding things straight with your hands. They were a combat aircraft originally and weren't meant to look like a million bucks. I'll stick to Wooten's Voodoo flying wings, myself.


Ed Cregger

hsukaria

Why did you need to plug one of the tubes? Too loud, or need more backpressure?

Cougar429

My Feedback: (3)

I pulled the 50 out of the Seamaster last night. Went through some agonizing over different options, ie. rotating the motor slightly to have the exhaust clear the wing. This was the least desirable due to retaining the loud stock muffler and having to grab a new cowl from Fiberglass Specialties. Their stuff is great, but again, now would have to match the paint.

The second choice is bolting an EVO 46 in it's place. Unfortunately we're back to fitting it into the cowl. There was no way to get the stack height to fit and the spinner would extend too far forward. In the final analysis, for less power the EVO weighs almost 20g more, so that one kind of went out the window.

It was then back to my original idea to fit a different muffler. Finally drew up the plans for the adapter and if things work out will have an OS 873 with baffle bolted on. Will take some pics once it's hogged out of some T7075. May take some time since there is limited access to the Bridgeport.

Was wondering if anyone has gone this route and if it affects the performance and/or fuel profile.

badger5964

My Feedback: (6)

Yes, it is louder than the Fox factory muffler. With a tube plugged I'd say about the same sound level.

badger5964

My Feedback: (6)

[quote]

hsukaria

Since I don't have any experience with Fox engines, the 74 in particular, is the factory muffler (tilt up or tilt down) pretty loud? I still haven't started up mine yet.

fmichaelb

[/quote]
Since I don't have any experience with Fox engines, the 74 in particular, is the factory muffler (tilt up or tilt down) pretty loud? I still haven't started up mine yet.
[/quote]

Yes

Hobbsy

My Feedback: (102)

Just add one of those gray rubbery elbows and it will tame it quite a bit. Or, run down one of these Snufflers, they are good for up to a 1.20 sized engine and have anice sound. Just remove the back half of the Fox muffler and bolt er in.

50+AirYears

The Fox mufflers don't seem to be well known as effective mufflers. Just for example, I have a .36 Schnuerle that I fitted a flow thru muffler from a Super Tigre .35. With the stock Fox muffler, I measured 95 dBA at 13800 with a 10-6 APC. With the ST muffler (remember, a flow thru is not supposed to be as effective as a closed expansion muffler) I measured 92 dBA at 14400 rpm with the same prop. All I had to do was file down a couple locating nubs on the mounting face. Interestingly, fox at one time had a quieter muffler. Nobody bought it. Someday, I'll have to do some sound level readings comparing the one I have with a stock muffler on a .45 or .46.