Author Topic: Opinions of the Fox.15 BB (Read 5013 times)

frank mccune · « **on:** May 23, 2012, 09:12:37 AM »

Hi Gang:

What is your opinions of this engine? How does it compare agains other .15 "Sport" engines?

Any tips as how to get more performance out of this engine for Sport Racing events such as fuel props, plugs, modifications etc.

Stay well,

Franchi

Randy Cuberly · « **Reply #1 on:** May 23, 2012, 09:47:45 AM »

Well,
Brett Buck and a couple of others seem to make them fly quite a ways!!!

Not sure that's what Fox made them for but they are very popular for a particular West Cost event called the Fox Hurl!

Not much good for anything else in my Humble Opinion.

Randy Cuberly

Andrew Tinsley · « **Reply #2 on:** May 23, 2012, 10:11:23 AM »

Hello,
I suspect that the real problem with the Fox 15 is the lack of decent QA. I have had several and I find mine are pretty good engines and fly what I want very well. On the other hand most of the others I have seen are pretty useless in the power dept. I have been lucky with them and I suspect that it is not usual. Mine are not up to up to an LA 15 in power, Probably 75%, but they are docile and easy starting and quite able to fly stuff in good style.

You have to get lucky once in a while!

Andrew.

Brett Buck · « **Reply #3 on:** May 23, 2012, 10:50:31 AM »

Quote from: Randy Cuberly on May 23, 2012, 09:47:45 AM

Well,
Brett Buck and a couple of others seem to make them fly quite a ways!!!

Not sure that's what Fox made them for but they are very popular for a particular West Cost event called the Fox Hurl!

   Randy, Randy, Randy, what are we going to do with you? The Fox 15BB is not allowed, Rule 2.0, plain as day. The ballistic coefficient is far too high (same size, roughly, as the 15 Slantplug, but much heavier). You want to have a demonstration event, then that's another story, Rule 17 44 (sorry) lays it all out for you, but this is ILLEGAL.

   A self-appointed Deputy Commissioner of the Hurl, I will be reporting this misinformation to the board, and Commissioner Fernandez, at my earliest opportunity. Normally a simple misunderstanding wouldn't warrant much action, but we have had to start taking a hard line against false Hurls, what with people now hurling non-standard engines like the McCoy 19 Redheads, and a reported ST G20/15 hurl outside of Milan, the integrity of the sport is at stake.

   Brett

RandySmith · « **Reply #4 on:** May 23, 2012, 12:38:30 PM »

Whoa!!!!! Boy, Randy , are you in trouble now !

Chris Wilson · « **Reply #5 on:** May 23, 2012, 04:52:41 PM »

Quote from: frank mccune on May 23, 2012, 09:12:37 AM

Hi Gang:

What is your opinions of this engine? How does it compare agains other .15 "Sport" engines?

Any tips as how to get more performance out of this engine for Sport Racing events such as fuel props, plugs, modifications etc.

Stay well,

Franchi

Put a diesel conversion head on it - Davis Diesel makes a nice one for them.

M Spencer · « **Reply #6 on:** May 23, 2012, 06:20:15 PM »

If its the nasty 70s BB schneurle , they did some for the world champs combat maniacs . 1/2 bore cranks & 22.000 rpms , but didnt have a great life expectancy at that output .
Think it was 20 % Nitro , keep em rich .

Randy Cuberly · « **Reply #7 on:** May 23, 2012, 08:44:46 PM »

Quote from: Brett Buck on May 23, 2012, 10:50:31 AM

Randy, Randy, Randy, what are we going to do with you? The Fox 15BB is not allowed, Rule 2.0, plain as day. The ballistic coefficient is far too high (same size, roughly, as the 15 Slantplug, but much heavier). You want to have a demonstration event, then that's another story, Rule 17 44 (sorry) lays it all out for you, but this is ILLEGAL.

A self-appointed Deputy Commissioner of the Hurl, I will be reporting this misinformation to the board, and Commissioner Fernandez, at my earliest opportunity. Normally a simple misunderstanding wouldn't warrant much action, but we have had to start taking a hard line against false Hurls, what with people now hurling non-standard engines like the McCoy 19 Redheads, and a reported ST G20/15 hurl outside of Milan, the integrity of the sport is at stake.

Brett

UUUhhhhhhhh...Sorry! I'm in the corner right now memorizing the rules!!!

Some of these things seem a little strange.. Actually I guess given the folks that made them up I guess they are not too strange...Uhhhh... not the people the rules!

Randy C.

Chris Wilson · « **Reply #8 on:** May 23, 2012, 10:52:55 PM »

You Amerikans, do strange things like the hurling of 15 foxes!

What did fox ever do to you?

dennis lipsett · « **Reply #9 on:** May 24, 2012, 07:17:34 AM »

Quote from: Chris Wilson on May 23, 2012, 10:52:55 PM

You Amerikans, do strange things like the hurling of 15 foxes!

What did fox ever do to you?

They were made, They are fulfilling their true purpose .

Dennis

Chris Wilson · « **Reply #10 on:** May 24, 2012, 05:19:08 PM »

Quote from: dennis lipsett on May 24, 2012, 07:17:34 AM

They were made, They are fulfilling their true purpose .

Dennis

Yeah I walked into that one Dennis!

Brett Buck · « **Reply #11 on:** May 24, 2012, 06:12:13 PM »

Quote from: Randy Cuberly on May 23, 2012, 08:44:46 PM

UUUhhhhhhhh...Sorry! I'm in the corner right now memorizing the rules!!!

Some of these things seem a little strange.. Actually I guess given the folks that made them up I guess they are not too strange...Uhhhh... not the people the rules!

The rulebook has been honed to perfection over years of careful work and contest experience. While they may seem confusing to the neophyte, rest assured that the rules are are correct and maintain both the spirit and, yes, I will say it, *majesty* of the event.

Brett

Brett Buck · « **Reply #12 on:** May 24, 2012, 06:14:04 PM »

Quote from: Chris Wilson on May 23, 2012, 10:52:55 PM

What did fox ever do to you?

That's a matter for the courts.

Brett

50+AirYears · « **Reply #13 on:** May 29, 2012, 01:23:33 AM »

Gee, I've been using Fox .15s since the days of the Rocket, and never had any problems with them. Easy starting, decent power. In fact, on my RC planes, (Im not predjudiced, I fly anything) I was the only person using that sized engine who could routinely take off from deep grass. Currently I have at least 14 Fox .15s, all of which have flown, except for my newest BB. In fact, I only had one that didn't run when I got it. Seems the disgruntled former owner had taken it apart before running it because he heard a rumor that Fox engines came filled with tooling chips, didn't find any, and put it together with the piston baffle on the exhaust side, not the bypass side. Bought it for $2.00, put it together correctly, and had a fine engine.

Bill Heher · « **Reply #14 on:** May 29, 2012, 07:58:04 AM »

I have a couple of the Schneurle .15s with the bolt on Venturi, I think Fox may have sold them as RC also.

Flew one on a Ringmaster Jr., it hauled butt, at least as good as as a Cox Medallion .09 I had on it also. It is kind of porky, but runs pretty good.

kenneth cook · « **Reply #15 on:** May 29, 2012, 06:27:09 PM »

One modification I think that would be beneficial is to make a new head button using a Nelson plug. The Fox.15bb is the only engine I know the requires a short standard plug. I truly believe you certainly could see more performance from the Nelson. I've seen these engines run pretty strong. Ken

dennis lipsett · « **Reply #16 on:** May 29, 2012, 07:49:20 PM »

Quote from: kenneth cook on May 29, 2012, 06:27:09 PM

One modification I think that would be beneficial is to make a new head button using a Nelson plug. The Fox.15bb is the only engine I know the requires a short standard plug. I truly believe you certainly could see more performance from the Nelson. I've seen these engines run pretty strong. Ken

If you are looking for more peformance from it the venturi is too small.

Dennis

50+AirYears · « **Reply #17 on:** May 29, 2012, 09:44:39 PM »

I remember a discussion of the Fox Schnuerle BB CL Fox .15 (Boy, that description made my fingertips a bit sore) in a CL Combat column in the old Model Builder. Words to the effect that for CL .15 combat, one could use the Fox Schnuerle for $29.95 (yes, that long ago) or get an engine with about 200 more RPM for something like $249.00 with a (Nelson .15?).
I've never had any complaint about Fox engines, except for one .15 Schnuerle that needed a hefty plastic screwdriver handle as a chicken stick for the first 5 or 6 starts. The MA 8-4 prop I was using actually cut into the plastic, the engine was so tight. Took another 20 runs to be able to use an electric starter. Got over 3000 flights on 4 ounce tanks with that thing before I had to replace the piston/liner. Lat count, I had about 56, from the standard .049 upp to a .78 RC. Just about any of them I've used will normally hand start on 1 to 3 flips. Of course, I usually use at least 20% oil, most of it castor in my fuel.

Joseph Patterson · « **Reply #18 on:** May 30, 2012, 06:19:45 AM »

I've only had (1) Fox 15 BB which I used on a Ringmaster Jr. It was way more power than the Jr. needed. Started very easy and mine took needle settings really good. I still have it and plan on building another slightly larger stunter for it. Ran it on Red Max 15% N and 22% all Castor many years ago. A good little motor.
Doug

Mike Greb · « **Reply #19 on:** May 30, 2012, 03:16:46 PM »

An eazy way to get more horsepower out of the engine is to replace the NVA with a fox 35 NVA. It has a smaller spraybar dia. that is good for an eazy 1000 rpm.

Chris Wilson · « **Reply #20 on:** May 30, 2012, 05:01:09 PM »

Quote from: Mike Greb on May 30, 2012, 03:16:46 PM

An eazy way to get more horsepower out of the engine is to replace the NVA with a fox 35 NVA. It has a smaller spraybar dia. that is good for an eazy 1000 rpm.

Good point Mike and I have always thought that the spigot type of spraybar as the ultimate in clearing the intake throat diameter without going to toooo much trouble.

Another good method is to simply machine down the central part of the spraybar if there is enough meat left on it to do so.

Cheers.

proparc · « **Reply #21 on:** May 31, 2012, 06:14:20 PM »

Quote from: 50+AirYears on May 29, 2012, 01:23:33 AM

Currently I have at least 14 Fox .15s, all of which have flown, except for my newest BB.

So that's what happens to them when they hurl them!!

50+AirYears · « **Reply #22 on:** May 31, 2012, 09:42:02 PM »

Gee, never tried it without a plane attached. Except one time when I had all 4 regular 4-40 mounting bolts snap off. Another club member spotted where the engine fell into a soy bean patch, so it only took us about an hour to recover it.

Mike Greb · « **Reply #23 on:** June 01, 2012, 09:53:11 PM »

Start one in your hand on prime and let it go it will go about 5 to 10 feet.

50+AirYears · « **Reply #24 on:** June 02, 2012, 12:59:49 AM »

Back about 1966, in the AF, I made a trade. Gave a buddy one of my Fox .15X RC engines, got back an OS .30 RC and $5.00. He put the engine in a Graupner Bergfalke glider he built. Used a (Grundig?) radio, a German radio that was multi channel, but instead of reeds, it used plug-in audio filters to decode the tones. It could build up into a pretty hefty brick. He got many flight on it. For relative size/power, I think he got the better deal. That .30 had less power than any of my Fox .19s. Or even my current .15 BBs.

Jim Thomerson · « **Reply #25 on:** June 03, 2012, 06:23:36 AM »

The Fox BB 15 is the engine of choice for the Sport Goodyear I have seen flown in the Dallas area. I haven't seen any recent timings, but a couple of years back 95 MPH (on suction) was very good. One time Gene Hemple was attempting to beach run one lighting the plug with my 2-volt battery. It would just kick back. Changed to the usual glowstick and it started right up.