fujiman

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NO TUNED PIPE. just the front manifold piece of the pipe and the copper pipe elbow. open exhaust so to speak. had no idle problems at all. it would idle all day long and transition flawlessly and clean. the 1000 rpm gain is from the enlarged throat of pump carb. and pumped fuel to handle the trans. thru midrange. i never ran this system on my hawk in the fw-190 tho, (i was just explaining how perry pump and carb. works and the poss. rpm gain they say you'll get) just the webra .60 perry carb. and fox adapter.

hsukaria

"NO TUNED PIPE. just the front manifold piece of the pipe and the copper pipe elbow. open exhaust so to speak"

Must have been louder than blazes

earlwb

Talk about loud, After I had refurbished my old Fox Blue Head .60 engine I test ran it. No muffler. It does use a rotating exhaust baffle though. It broke the audio input on my digital camera that I recorded videos with. Anyway I can't believe that I actually flew a couple of airplanes with this engine sans muffler many many years ago. No ear protection either. Plus for those who are challenged with regular RC carbs this engine uses a three needle carb with adjustments for low, mid-range and high speed.

I actually have the engine being used today in a airplane still. It has worn out a few airplanes over the years and keeps on running. Granted it doesn't develop lots of power like the more modern engines do, but it still runs good though. Of course it now sports a muffler on it.

Duke Fox developed the first engine in the mid 1960's as a .74 for pattern flying. But the FAI and AMA decided to limit the engine displacement to .61 or 10cc size, so he had to come out with a second .60 size engine because of the rules. The engine evolved over the years into a .78 displacement engine. The .78 was still being sold in hobby shops up into the 1980's. The engines were quite advanced at the time, needle bearings on the connecting rod and the three needle carb of course.

hsukaria

It still looks new!! Going back to the Hawk 60, why did Fox quit making those and switch to the Eagles? Cost reduction? I looked at *bay and the Hawks selling there were quite expensive with a bunch of vultures hovering over them. I knew I would never be able to get one unless I pay $$$$$$$$$$.

vertical grimmace

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That is really cool.

fujiman

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it wasn't bad as i remember. back then i was flying at a large dry lake bed in Joshua Tree, So. Calif. in the hi desert. it's near 29 palms marine base. no noise restrictions or problems there. public land plus i flew loan wolf, no club or politics.

hsukaria

I drove through there a couple of times when I used to go to Edwards AFB in the 80's.

earlwb

Yes the Hawk .60 was expensive to make. The finned nitrided steel cylinder used a lot of metal. You would take a bar of steel, and machine it to make the cylinder, fins and all. Then it had to be hardened, and bored or ground to size. So they had a lot of material to machine off to make a cylinder like that.

hsukaria

Plus it was steel, not aluminum. That is more work to machine. But I like the sleeveless design. Similar to the Norvel (NV Engines) design, although I think theirs is aluminum cylinder instead. Was the Hawk a low nitro engine, or regular 10-15%?

spaceworm

Do you power both plugs to start or is one better than the other for starting? Does the one not powered during starting come on due to heat and methanol during the run-up?

Still have my Fox .35 stunt from 1953. Lots of CL combat hours on it. I am sure it would start right up. No muffler provisions though.

earlwb

Spaceworm, you only needed to put a glow ignitor on one plug, your choice, it didn't matter for starting. The other plug would heat up from the combustion process by itself. Everyone only put dual plugs on for a few years. At first everyone wasn't sure as to how reliable the plugs were and the engines seemed to run better with dual plugs. But as engine designs improved, the all quit doing it. One plug was sufficient. I used a Davis Diesel muffler and clamped it on.

Huskaria, The Hawks were lower compression so they worked with more nitro than the engines did in the 80's. Also the engines liked to rev up more, they didn't like being lugged down with bigger props. So something in the 11x7 to 11x7.5 to 11x7.75 was the prop to use. If you were wanting speed you could go smaller in prop size to really let the engine go. Fox advertsed it that the engine could turn 22,000 RPMs reliably. Although I never really tried it myself. I had thought about putting the engine on the front of one of the Horizon Jackal prop jets though. The Hawk .60 is more light in weight than a regular large frame .61 engine but a little more heavy than a .56 engine.

fujiman

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OMG!!!!!!!!!! my rc deezz is over the top!!!!!!!! i own 12 hawks maybe more, i lost count, ain't that just sick!!!!!!!!!! why o why!!!!!!!! just had to have them, all that i could find. i need help for sure!!!!!!!!!

hsukaria

I know the feeling, I have some extra engines too. If you need help getting rid of one of your Hawks, I am willing to help out!! Let me know if you are wiling to sell or trade one of them.

earlwb

I have included some images of the instructions that came with one of my Hawk .60 engines. Also note that Fox suggested a 11x7 prop as being the largest to use. he also stated they had run the engine up to 25,000 RPMS too. But I wouldn't advise doing that today.

In Peter Chinn's Hawk .60 engine review article that he did in 1975. Peter did mention more strongly that you needed to be careful with the engine break in as they fitted the pistn much more closely or tight. So one needs to break in the engine more carefully. You usually don't see them mentioning break in all that much with the engine reviews.
ref http://sceptreflight.net/Model%20Eng...Hawk%2060.html

hsukaria

I see that the Hawk had the crazy butterfly carb. Is that something of concern? I suspect that is the reason some guys used the Perry carbs?

Hobbsy

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Old Fox .50 is rebuilt, new Boca Bearings and cleaned up, mostly. It has finger chasing compression. Picture #2 is a Happy Harry's Hand Dandy Hickey Dicker for deglazing small cylinders. It works without doing any harm. I chose a head button with a more open combustion chamber since it's going to run on 10% fuel for the limber up. I knocked the old bearings out and installed the new ones cold, no problem The sandpaper is very fine 600 or something that. The got saw dust on it some how.

hsukaria

Nifty!! What size prop do you plan on using? Did you modify the head button, or was it already made for higher nitro?

Hobbsy

My Feedback: (102)

The prop seen is a 10.5x6, close enough I think, the head button is one I have as an extra. I think someone got It from FlightLine.

fujiman

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PM me and we'll talk or my e-mail [email protected]

earlwb

Well I sorta liked the old butterfly carbs, but I liked the older three needle carbs too. But there are people who were totally flumuxed by them.
The trick to a butterfly carb is that the low speed needle interferes with the high speed needle adjustment. So if you did change the low speed for some reason. You need to recheck the high speed needle.

The other simple trick is for the fuel inlet nipple. You use a short length of black neoprene fuel tubing on it. The neoprene tubing sticks to the nipple and tends to glue itself onto it. At the time Fox made the carbs, we only had clear tubing or black neoprene tubing available. The silicone tubing didn't exist yet. The silicone tubing will slip right off the nipple if you try to use it. But using a short length of black neoprene tubing and then connect it to the silicone tubing works fine.

Anyway that is it, the carb works like normal otherwise. They tend to be pretty neat as the carbs tend to be a little lean through the mid-range thus the engine doesn't bog down with excess fuel.

Hobbsy

My Feedback: (102)

Fox friends, I just ran the re-bearinged Fox .50, it's a winner all the way. I did change the carb to an EZJust carb which I know is set up, it was partially clogged with castor, imagine that. As I ran it longer it kept going rich. I attribute this to the gelled castor dissolving and opening the metering slots.

Fox .50 with new BOCA bearings
Fuel==WildCat 2/4 10% with 18% full synthetic, don't holler at me, it's all I have
Prop==Graupner 10.5x6
Plug==Fox Idlebar
Muffler==stock with Mac's 90 sized tuned Quiet Pipe, no effect on rpm at all.
Max rpm==12,987 after 30 minutes after the first 15 minutes it was 12,850. It may gain a few more.
Idle==2,150 sustainable for ?
This engine is uncannily smooth with a very clean transition. Air bleed in center of air inlet.

All in all a pleasant experience.

hsukaria

Good to hear about the Fox 50, Hobbsy. What is the purpose of the Mac tuned pipe, to reduce noise from the stock muffler?

I have been breaking-in the Fox 45 with new Frank Bowman ring and replaced cylinder liner. I don't have a stock muffler for it, so I modified an OS muffler with a mousse-can at the back-end. I have not captured any tach readings yet that are meaningful. I am running 0% nitro with about 20% oil, synth/castor mix. I switched up from a 9x6 to a 10x6 prop yesterday as it began to smooth out. Once I switch to the 5% nitro and final props (11x6 and 9x8), I will get some tach readings. The throttle response is instant, even with 0% nitro. That's my first experience with a smaller Fox. Only previous experience is with a Fox Eagle 74. I have to admit, I think I like the smaller 45 more than the 74, not so intimidating. Later this Spring I will bench test a couple of smaller C-case 40 engines. But I have to get some 20% castor fuel first because they are the lapped iron piston/steel sleeve type engines.

Hobbsy

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Yes sir it is just for that and is very effective. As you no doubt know the stock Fox non muffler is very loud, the 90 sized Quiet Pipe nearly silences it without effecting the tune. It does fill up with water unless I tilt it down some. I always run a 12x8 on the .74, in the 80's Fox actually recommended a 12x8.

spaceworm

Hi Dave,

I have had mufflers, including mousse cans, load up with oil and unburned fuel. What I have done is to drill a small hole, say 1/8 inch, at the low point of the muffler. The pressure in the muffler blows out the stuff, but is too small to affect the tune or noise.

I have a flange mount Fox carb in my stuff that I don't ever plan to use. I will try to find it and have you ID it and give it to you if you want it.

Best regards, Richard

Hobbsy

My Feedback: (102)

Thanks Richard, I'll gladly take a peak.