Hallo racing boy´s,

who news more details about the Webra Bully 75 racing engine.
I was told this was the engine for the F1 racing class - but where are the details.

Please let me know.

Best regards Mr. f3d

nobody has really prooved that the Bully was the engine for F-1 that i know of...my dad used on and was convinced that it was faster, but never raced it...so everyone is now using a Zenoah GT-80...the Bully is a very very heavy engine compared to the GT-80 anyways.

Cole

If memory serves me, the Webra Bully won the first F-1 race at Madera in 1993. Flown by Bryan Keil of Classical Racing in a Paul Steiner Cosmic Wind. That one was gas and it was later converted to glow.

These days, everyones using the GT80.

Hallo Jet Viol8r,

have you more details about prop size .......

I want to use such a engine in a F1 style airplane and need some more information .

Best regards M. Jakob

APC 20x20. I've been out of racing for several years. I think they have been discontinued. I don't see them listed on their website. www.apcprop.com

They have since created a stock F-1GT class around a stock GT80 and APC propellor. Look under Giant Scale Formula props: 22x8 and 22x10.

I was probably the last person to race a Bully 75 in Giant Scale Racing. I last ran it in 2000 at Jean, Nevada on a GR-7 in the F1 class. I ran 25% Nitro in it against other recommendations the previous year to run only 5% (racer's psych). I ran a 20 X 21 Bolly prop cut down to 18" in length. The engine runs very strong. But as a single cylinder, it does shake and at a 2lb weight disadvantage, that shaking takes it's toll. It would start with a backward flick of the spinner. I never used a starter on it. I paid $2,000 for this engine in 1995 and was determined to get some use out of it.

My cowl attachment screws had to be replaced after every flight. The airframe is a Race Pro built by Joe Marine. Joe set the firewall and mounted the engine for me and advised that I use the Hyde radial rubber shock mount. That did not work. The weight of the engine in the high "G" turns caused the mount and engine to sag and the spinner would rub on the bottom of the cowl ring. I eventually braced the bottom of the engine and bolted through the Hyde mount to totally defeat it's dampening effect. My speeds came up and I won a heat or two at Jean. Ended up I believe 5th in the Silver. The GT80 class came along so I pulled the engine out of the GR-7 and installed a much smoother twin Zenoah GT80. I am still racing the same GR-7 but now in the GT80 class at Parker.

I still have that Bully 75 that was worked over by Ken Laski and ran on Alcohol with twin glow plugs. It was never crashed or even broke a prop. I also have three others that were provided by UAV Engines Inc (legal owners of the name "Bully") and none of those three have ever run. No two engines are exactly alike. One of them has "Webra" actually engraved in the crankcase. One is set up with a spark plug and ignition module. All have the rear Carburetor and twin Reed Valve plenum. I upgraded all of them to the racing carb setup with the short pulse tube coming from the rear rather than from the side of the crank case.

I hope to some day build a giant Ugly Stick and mount the Bully 75 on the front out in the open to show off its shining polished aluminum case and purple head. This would have to be a 10 foot wingspan Ugly Stick. One engine is earmarked for the giant 1/2 scale Farman Moustique that Larry Klingberg built and showed at the 2005 AMA Convention. It will probably be the spark Ignition engine as soon as I get it mounted on a test stand and tuned to start and run easily on gas.

I don't remember a Bully racing in 1993. When I bought my first Bully in 1995 I was told they would not run as delivered. Mine was given to Ken Laski to "find out what it would take to make it run" and he did. I mounted it on an Ole Tiger and was present at Madera '95 but did not have the plane test flown so did not race it. I did loan the rear backplate and carb (at Ken's request) to someone else (I don't remember their name) to race and it did well. If I remember correctly it was involved in a mid-air and crashed but my backplate and Carb were not hurt and quickly retrieved.