turbo.gst

My Feedback: (8)

Does anyone remember a Nitro Special combat engine( .35 or .36) produced by Fox in the late 50's / early 60's. It was designed to run on very high nitro fuel like 50%. The archived Fliteline Solution site talks of a Combat Special ( also high nitro) made in the early 1980's. I was just curious if anyone ran one of them or had any knowledge of the engine.

turbo

earlwb

They have a history of the Fox combat 35X and 36X engines here as written by Bill Ives:
http://www.clcombat.info/foxhistory.html
a Fox 36X instruction manual can be acquired here: http://www.rcgroups.com/forums/showa...5&d=1298465475
more Fox Engine manuals here too http://www.rcgroups.com/forums/showt...955929&page=11
The props ranged from a 10x6 for stunt to a 9x7 for combat and a 8x8 for rat racing.
The fuel was Fox Missile Mist. Which was 24% nitromethane and 17% castor oil, the rest methanol and some special additives.
http://www.foxmanufacturing.com/inde...oducts_id=1488
I do not remember anyone running 50% nitro glow fuel in them at the time I was using mine many years ago. But maybe they did in some speed racing events.

I happen to still have several of the older model engines myself. I used them many years ago for CL combat at the time and also stunt flying too.


I even flew one where I glued a Kavan RC carb on it.



The engines had a venturi insert that you used for slow combat. This restricted the engine more but you didn't need to pressurize the fuel tank either.


You removed the intake venturi restrictor for fast combat or rat racing, and you then used pressure to force feed fuel into the engine.
Either crankcase pressure or a bladder tank was used then. The later Fox engines had a even more simplified needle spray bar for pressure tanks.

NM2K

My Feedback: (14)

I bought and flew my Fox .36X while stationed at Gila Bend AFB in Arizona back in 1966. What a terrific engine it was. It ran on any kind of fuel we could find in those days. After I was restationed to Luke AFB, I had a steady supply of Missile Mist fuel. That engine really perked up when burning Missile Mist. I never got around to trying a prop smaller than a 10x6 on it. It was scarey fast on that prop. I hate to think of how fast it would have been on a smaller prop. I flew Shoestring Stunters at first, but then I switched to Voodoo flying wings. Talk about scorch up a circle! Those were the good old days.


Ed Cregger

tigrejohn

My Feedback: (7)

If I remember correctly, the Fox motors that were considered competition grade or Combat Specials either had a name attached or an "X" added to the engine size. I think the order of development was the 36X, then the Rocket, then the series of Combat Specials. The last one was the Combat Special Mark VII. The last one was developed to compete with the Nelson's but couldn't quite hack it. I believe the ABC versions started with the Mark VI (or maybe the IV, but I can't say since I didn't have any IV's).

The earliest competition motors had round backplates and square venturi (36X and Rocket). The series of motors that were actually called Combat Specials and CS Mark "X " had the square venturi and the barndoor backplate (to make Schnuerle manufacturing easier). This case design was also used for sport and competition 40"s.

I flew competition C/L Combat for almost 20 years. Started out with a Rocket, and finished with VI's. Could fly all day on 25% fuel. Would sometimes use 45% at a contest, but depending on the weather 0might have to use a thicker head gasket.