Konrad

True!

Konrad

earlwb,
Nice rebuild. I too had noticed that there was no chamfer on the rod to clear the crank pin fillet radius. I'm surprised I never saw a galled crank pin due to this. Is there some reason the rod doesn't move up on to the fillet? I also notice that your crank has nice cut collet splines. Mine are just knurled into the crankshaft. This one is from Dukes personal collection and from the last production.

Anybody know why Duke felt he had to add these splines on a split collet drive. These splines often made it difficult to get the drive washer to center properly.

As this site is having issues I haven't taken the time to annotate the photos. If they post I'll come back later and highlight the issues.

All the best,
Konrad.

All photos and drawing are by the author, me!

earlwb

I think the crankpin is a press fit into the crankshaft so as such it doesn't have a radius machined into it at the joint. so then they don't need a recess machined into it to clear the radius that isn't there. to make a one piece crank gets expensive as you have to machine off a lot of material, and if a error occurs you have to toss the entire assembly. With a crankcase made up of multiple parts, you can reduce the waste and have less problems with errors as they creep in from time to time. so i can see them making the crankshaft out of multiple parts.

My theory on the splines on the crankshaft...
1) a production expediency to save parts that would otherwise have to be recycled. the splines make the shaft slightly larger in diameter.
2) more than likely, a simple issue, the inner collet has something to bite into so it doesn't slip as the engine is running. the outer thrust washer fits onto the inner collet, which fits over the crankshaft. You can see in the pic how the splines dig into the inner collet a little which would improve the bite so it doesn't slip. since Fox did this for quite a few engines and not just a short production run it much be a effective solution.
3.) all of the above.

blw

My Feedback: (3)

This is getting into the realm of Star Trek or Star Wars, and has very little to do with reality.

Konrad

The crankpin is not just pressed in, there is a fillet radius. I try to show in one of the photos that the rod does not go all the way down to the web. Now later Foxes did use multiple piece crankshafts that were electron beam welded together prior to finish machining.

As to the spline issue the split collet should take care of any size issue. And the prop nut should drive the collet tighter on and into the shaft and drive washer. I think the issue Duke was dealing with is the public's perception of how the collet worked. Most (all other) engines that I know of that use a collet to drive the drive washer use a smooth shank crankshaft. Fox (Duke) is the only engine I know of that splined this area.

Sport_Pilot

Is there anyone that can chrome or nickle plate the bore to bring it up to spec?

Konrad

I did with my F3D engines, chrome. I did find one of my "experimental" sleeve in the bottom of my junk drawer that shows chrome over the hand reworked porting jobs. If anybody cares I can take a photo of this next time I'm home. Just a warning it is a rather crude experiment and not on the subject of Fox.

As it has been noted one needs to look at the cost to benefit equation. Now as to spec these were mine. I was experimenting with tappers and fit, along with porting configurations. Some worked most didn't, for the most part it cost me only my time. I will say that for me a sport engine is not worth the effort.

Nickel would be rather easy as it plates to size. No need to machine to a finished size, assuming that the parent material is true. But then electroless nickel is not a high performance coating and therefor not really worth the effort to reclaim an electroless nickeled liner. One would be much better served if one made a brass sleeve from stock and chrome plated it making it at least an ABCR engine.

The reason the C/L speed guys first went to brass was because it was so much easier to chrome plate that steel (no need for protective strikes, cooper or nickel). They then found that the tappers needed for a brass sleeve were on the order of one magnitude greater than a steel sleeve. This and the development of high silicon aluminums gave us the true ABC engine that Super Tiger and many of the other Italian Stallions first brought to market.

All the best,
Konrad

Konrad

Is that the issue you have, reality? If you want to run with the pack then by all means run what you have and how you have been.
If you want to gain that little extra take the time to learn how things work. Is it worth the extra effort? Only you can make the determination!

All the best,
Konrad

w8ye

My Feedback: (16)

George Aldrich started a business in 1968 that was eventually based on stripping old chrome or nickel and re-hard chroming the cylinders then honing back to the proper size. He did all this at his home shop until his death,

https://www.modelaircraft.org/files/Aldrich-George.pdf

George was a regular contributor to the model airplane engine forums even back in the old "Mail Box" days before the Internet.

Konrad

Like I said, It is quite doable and even easy, but is it worth it? With the cost of chrome here in the states for a sport engine I'd have to say no!

earlwb

I test ran the old Fox Hawk 60 that I had replaced the bearings and piston ring on earlier.
It fired right up and ran pretty good right off the bat. I ran it extra rich for a while to ensure oil got back into the parts real good.
Then I leaned it out and ran it good.
With a Master Airscrew 11x7 prop I was getting around 11,700 RPMs using 5% nitro glow fuel. I think the new bearings still have some drag to them and the piston ring isn't seated really good yet. So after a while it ought to turn some better RPMs.
I have a tuned pipe header, but I was running a canister muffler instead.





A little trick to using the old Fox carbs with the cast in fuel inlet fitting on the carb. You use a short length of neoprine fuel tubing instead. When the carbs were designed, we didn't have silicone fuel tubing yet. Just poly plastic fuel tubing or black neoprine tubing. Anyway the neoprine sort of bonds with the aluminum fuel inlet nippleand sticks on quite well. The silicone fuel tubing will simply slide on off when you try to use it.

Konrad

Bearing drag, what like alignment issues?
Nice post about the neoprene fuel tubing.
I have to ask about running the engine with the ni-lighter attached, is it a save practice? I have had the glow driver fall off and get tangled in the prop. Why the need to keep the plug driven? Is it an old contaminated plug that you use for your break in (the catalytic reaction is compromised)?

fujiman

My Feedback: (133)

ssswwweeeettttt!!!!!!!!!!! i simply love those hawks!!!!!!!!! best runnin' engine i ever had. loved them so much i have bought all that could and can find!!!!!!

earlwb

Konrad, I think there might be a bit of bearing drag in it. The new bearings felt a teensy bit stiff, but it might have been the grease the factory packed them with. The engine loosened up pretty good, but still feels a teensy bit draggy, when you flip the prop over. But a good flip has the prop bouncing back and forth, so maybe it is just my imagination. Plus it has a new ring in it. But since it had many gallons of fuel run through it before, I didn't spend much time breaking it in.

Yes you are correct, not a safe practice. But when I first ran it, it was running super rich, and spitting fuel like crazy. So I was figuring it out at the time. I was using a old plug for the inital runs, the engine was running way super rich at that point, so after a few minutes to ensure it got oiled up good (connecting rod mostly) I started leaning it out and tweaking the carb as needed. While leaning it out, i went to adjust the idle mixture screw and discovered I had scavenged it for another engine years ago as it wasn't there. Yeah that'll make it run real rich. So I had to scavenge a idle mixture screw from a old Fox 40 big case I had in the old engine box. You can see the idle mixture screw was missing in the second pic with the ni-starter on it. I was thinking, boy it is running awfully rich there, spitting fuel out the carb, etc, time to tweak the idle screw some, whoa, no idle screw, sheesh, go figure!

when I have problems with a engine, if I suspect the glow plug, I replace it and put the old one in a old glow plug box. I then use the old glow plugs when running a engine initially, as breaking in the engine, or something, could foul a glow plug element. So why waste a brand new glow plug right off the bat. I have had new engines eat a glow plug or two pretty fast before. Some of the old glow plugs were perfectly fine, they just got swapped out during debugging at the flying field. But I have had glow plugs go bad, that glowed brightly when powered up, but the engine would not fire off with the bad plug installed. So when in doubt swap the glow plug out and see what happens.

I was trying to remember how well the engine ran many years ago, it outlasted several airplanes. it even has a little crash damage on the head from a nasty inverted landing one day. Maybe my memory is faulty nowadays on how well it ran many years ago. Maybe I should have run a Zinger prop on it as I remember using Zinger 11x7's way back then. I remember getting around 14,500 rpms running Fox Missle Mist with a tuned pipe on the last pattern plane the engine was on, a Wolfgane Matt Atlas. It was later the bearings got real loose, so I swapped out the engine for a Fox Eagle III at the time.

Oh yeah, here is a short video of when I was messing around with the Fox Hawk 60 engine. I found out later that the throttle arm was bumping up against the test stand on the right side, thus it wasn't idling too low.
[youtube]http://www.youtube.com/watch?v=iv0scgphQGU[/youtube]

Bob Paris

My Feedback: (13)

Hi Guys,
I'm about ready to up grade my Fox .50 powered Telemaster 74. The model came out a little heavyer then planed, but with the .50...you had to do a take off run, to get airborne. Kinda like the old day's...but after 50 good flights, I feel the model could use a bit more power. I use a Zinger Pro 11x5" prop on the .50 and it pulls the plane right nice...but with our winds and rough air...a wee bit more power would be more safe. I stumbled accross an older Fox Eagle .60, and it has an exhaust restrictor tied into the carb...but no muffler. It looks like there are two places on the exhaust where you may be able to tap a thread and install a muffler...but need to be educated on this engine-and if there is a muffler available for it. I have no idea how old it is, or if its better then the .50 I am now flying with...but I need more power and want to keep this model flying with Fox.

So Ok you Fox hounds...educate me on this engine. I am willing to trade for another, more newer Fox .60, but I need to know if this one is worth the effort to run and install on my model. I don't beleive the engine has ever been run and looks new. It has a piston ring, and good compression.

I love the Fox .50...and with a Perry carb...will idle so slow you can count the blades going around.

Soft Landings Always,
Bobby of Maui

Konrad

The Fox Eagle I you have is a great light weight baffled 0.60 but it is NOT as powerful as a well running Schnuerle ported Fox 0.50.
A muffler for that 0.60 maybe an issue. That along with what you describe as your concern with fighting wind would lead me to look for an engine that has more power. An old Fox baffled 0.78 would do it if you want to stay with old Foxes. But a newer Fox Eagle IV would give you an engine that you can find a muffler for, has a modern auto mixture control carb (AMC) and modern porting. Your Eagle I also has an AMC carb but is dated from the mid to late 70's.

I'd say go with a modern FOX Eagle IV.

The Eagle I is a good engine for what it is, I just don't think it is the best for your application

earlwb

You have one of the early examples of a Fox Eagle I engine. When the engine first came out, it had the exhaust baffle on it because at the time, no one was using mufflers yet. There are two types of mufflers that Fox made for the Fox 60 Eagle I and Fox Hawk 60 engines. The mufflers fit both engines interchangeably. The Fox .50 engine is actually a little more powerful than the Fox Eagle I .60 engine. So that probably would not make for a performance upgrade. But the .60 does turn a little larger size prop than the .50 can turn, so it might give you more thrust and pulling power. But that is hard to say if it will help or not.

The early type of muffler was designed to allow one to keep the exhaust throttle baffle when using the muffler. When using this muffler, you need to use some blue locktite on the screw threads. The muffler will still ooze oil out of the joint, so don't worry about it. You might have to carefully file on the engine crankcase exhaust outlet to remove any irregularities in the casting, as Fox at the time wasn't really interested in mufflers as no one was using them. The muffler was something of a add on later as clubs across the country were starting to require mufflers. Now these mufflers do not do much to reduce noise. So the engines are still quite loud with them on.


Later when Fox stopped producing the engines with the exhaust baffle, he came out with the flanged muffler. In this case the engines could use either the screws on the top and bottom of the exhaust port or the two mounting tabs on the engine. Also the flange covered the exhaust baffle holes when you removed the exhaust baffle.


Here is one of my later model Fox Eagle 60 engines with the muffler on it. The later models had the muffler mounting tabs cast in on the crankcase to allow you to mount the flanged muffler on it.


Alternate sources for mufflers. The mufflers for the OS .61SF, Thundertiger .61 Pro, TT GP & Pro .61, MDS .68 FS Pro all are really close matches. The muffler mounting screw holes are about 1 to 2 mm too close together though, but that can be corrected. On engines without the mounting ears or tabs on the engine crankcase, you'll have to use a radiator hose clamp to hold the muffler on. So that means you have to drill and tap a couple of holes in the muffler for the hose clamp.

Here is where I am using a Tuned Pipe header intended for a OS .60 SF engine that I modified to fit by cutting a slot in the front screw and using a nut on the screw.


Here is a example of using a hose clamp to hold the muffler on a engine:

earlwb

Since I happen to be discussing mufflers at this time. Here are some pics of when I modified a Davis Diesel Development 60 size Soundmaster Muffler for use on my old Fox .60 Blue Head dual plug engine. Way back around 1966 mufflers were not being used on the model engines. But the RC engines usually had a exhaust baffle to help in getting the engine to idle or run at lower RPMs. So putting a muffler on the old vintage engines can be a challenge.

So I found that the old Davis Diesel Development Soundmaster muffler for .60 to .91 size engines, is a good fit. I only needed to open up the exhaust inlet on the muffler a little bit. The aluminum adapter part actually has some excess material on it, so it is easy to machine it out a little to open it up more so it matches up better with the Fox engine exhaust outlet. it is not a perfect match, but it is close though. One could open up the muffler inlet using some files and a dremel tool as well.

I also used my lathe to make a couple of aluminum plugs for the holes left when you remove the exhaust baffle. With a clamp on muffler, the exhaust baffle linkage gets in the way, so you have to remove it.

I plan on running the engine on a Goldberg Tiger 60 ARF knockoff plane. I was going to build another SIG Astro-Hog, but the Tiger .60 plane actually cost less than what it costs in Monokote to cover the plane. So I couldn't resist.

Anyway, this same setup will work on the old Fox .74 (not the current Schnuerle .74) and the Fox .78 as well.









Enlarging the exhaust inlet opening some more to match the Fox Blue head .60 engine better.




and here are the instructions that came with the muffler. DDD provided a lot of information about how to reduce the noise that a model airplane can produce. The noise is not just what the engine outputs, but the propeller, vibration, and airframe resonance can all make noise too.
The image of the instructions is pretty large, so I post it here as a link instead.
i248.photobucket.com/albums/gg171/earlwbollinger/Old%20and%20Vintage%20Engines/Fox_Blue_Head_w_DDD_Soundmaster_muffler_06.jpg

earlwb

Oh yeah, here are some pics of the FOX three needle RC carburetor as well. it is actually a very sophisticated carburetor when you study it some. Especially when you think about the fact that this was way back in 1965, 1966 or so. The carb also had to be able to allow the engine to draw its fuel strongly, as they didn't have mufflers for muffler pressure or fuel pumps back then. Muffler pressure and or fuel pumps allows the engine designer to make the carbs larger so the engine can breathe better.

There is three needles to adjust on the carb. The main jet needle, the idle mixture needle and the mid range needle. The needles all affect each other. But after you get the engine to run OK, you adjust the idle or low speed needle first, then the mid range needle and then the main jet needle.
The fourth adjustment screw is for idle speed.

The carb has two small holes on the bottom of the butterfly throttle plate. The holes are not in the center. You can see that one hole with a very shallow groove is located in the L shape slot on the right side on the bottom. The mid range needle controls that hole and it also has a small hole where the mid range needle is located as well. The other main jet small hole is offset to the left of center on the throttle plate. You can see the holes in the pic below. So they actually have three holes where the fuel could be drawn into the engine from.

I got to wondering how Fox made the carb in relation to its intake opening. You'll see that the intake starts out as a round shape venturi. Then on the bottom it is sort of a square shape with a cutout for the main fuel orifice to be blocked off with as low throtte. The hole looks sharp like they used a broach to make it. So I think the inside portion of the round intake venturi was actully lightly pressed in after the squareish hole was made. You can see from the bottom pic that the round venturi has a recess up into the square hole portion of the carb body.

jeffie8696

If you get me the dimesions of the .60 Imight have a cheap muffler for you. Ihave 2 old Fox mufflers laying around abou the right size.

Konrad

Nice pictures!
I can't tell by the photos but is there a variable fuel metering orifice? Or is it just a staged progression uncovering the 3 fuel port.

earlwb

Sort of a staged progression as the holes are uncovered. Although the one mid range hole has a very shallow groove, so it can flow some fuel as the throttle plate rotates.

When I think about it some more, the one hole in the slot on the throttle plate might be the idle muxture hole. The hole at the top of the "L" shaped slot would be the mid range as it is directly below the mid range adjustment screw or needle. the offset hole on the throttle plate in the open there is the main fuel orifice and the carb body obstructs it at lower throttle settings. The carb body has that block of metal on the bottom to cover the main orifice as the throttle plate closes up.

Bob Paris

My Feedback: (13)

Thanks Guys...
Lots of great information, but I think I'll buy a newer .60 Eagle IV, and install this into my model. I'll just keep this older Fox .60 in my collection, for a future model. I have been very impressed with the Fox .50, and this engine just keeps running better, the more I fly it. I flew it today, and for a change, we had near calm winds until noon. A rare treat here in the tropics...but there is a storm brewing south of us, and we may get some rain tomorrow.

I also have a new Fox .40 BB I picked up in the early 90's and was trying to install it into a Sig, kit built-Liberty Sport Bi-plane...but the engine I have is short nosed, and just wouldn't fit well into the cowl. I could not find a way to install the engine with out distroying the cowling...so I will have to install another engine. I tried for a good two day's, working on the nose section of the Liberty Sport, with out cutting up the cowl, and decided to go with a T.T. Pro .46 I have. It will fit well with a Bison Pitts style muffler, having a much longer nose section to the engine and with minimal cutting, fit into the cowl.

Does anyone know where I can puchase a Fox Eagle IV wholesale...new or in good used condition ?

Soft Landings Always,
Bobby of Maui

Konrad

A Fox Prop Shaft extension might help move the engine aft.
http://www.foxmanufacturing.com/inde...roducts_id=900

These are just and aluminum spool and tube nut. Works great, as does all of Fox's products!

Select the offset you want and the thread size.

All the best,
Konrad

Cougar429

My Feedback: (3)

jeffie8696, I posted a request a few pages back looking for a muffler for my Eagle I bought mid November.

Can you post a pic or two and I'll have a boo?

On a related note: When I went looking to see how far back it was I see some of my pics have disappeared. Any ideas?