I have read much here on setting up the 25FP and 25LA for a "modern stunt run". My question is, do the same principles apply to the Brodak 25?

Thanks for your response Bob. I'm not able to make modifications. For the 25 FP and 25 LA Brett espouses I believe a 9-4 prop and a setting just less than peak RPM. With no modifications. I'm wondering about that approach for the Brodak 25.     

   I bought two brand new ones when they first came out. I had been using LA and FP .25s for a long time, was familiar with the Brodak .40, so I was expecting performance from the B-25 to be on par with the LA and FP, but with characteristics similar to the .40. I had a Ringmaster with an LA .25 on it at that time and it was an easy swap out after I had done a "per the instructions" break in. I run APC 10-4 props for the most part on the OS engines, and tried the same with Brodak, and it didn't make enough power to pull my hat off my head! I tried all sorts of props. The engine would needle fine, run where ever I set it at, and sound OK, just no power, really anemic! I posted to some other threads at the time about my experience and soon I got a call from Tom Hampshire asking me to send him the engine. i did so and a few weeks later got it back. I had marked all the parts when I checked the inside for any issues, and when I got it back, all my original parts were still there. What was different, was that he had modified the exhaust to a straight through affair. I bolted the engine back up to the Ringmaster and much better results!! It ran on par with the LA at least. I think the FP has an edge on over all power amongst the three. Since the B-25 and the B-40 use the same muffler, I did a few test flights on my profile Shark that I have a B-40 mounted on, and the straight through muffler changed the B-40 from the stable, predictable engine it was into a monster with an explosive break!! I liked what i had before that, so just put the stock back on and left it at that for that airplane. So in short, the exhaust was pretty restrictive. i had read where guys loved the engine for .25 sized club racing events, but never considered a "Potato in the tail pipe" scenario with the engine. I've put them both away , and haven't revisited them, but since then have never really read anything where anyone else has had any other big discoveries about them, hd any major issues, or any improvements. They evidently sell well still, and guys still club race them, especially down under. I might dig them back out soon and revisit them again.
   Type at you later,
    Dan McEntee

Hi, John.
I've not tried that approach but You should try it.
Brett is quite knowledgeable regarding to 20 to 25 size engines.

   Well,  a few notable specific examples, at least. My impression of the limited testing and observation of the Brodak 25 (which didn't exist when I did the original small engine experiments) is that the 25LA or FP setup is really not going to work. It was advertised as a "throwback" 4-2 break engine and that seemed about right. As such, it probably works well with a 9-5 or 9-6, but is very unlikely to work with a 9-4 or 10-4 the way the 20FP or 25LA does, nor would I put it on a typical 35-sized airplane like a Twister and expect good performance - it would probably fly the airplane, but not as well as a baffle-piston 35.

    Brett

     

There is a guy with a Ringmaster and a Brodak 25.
If I was needing info on a Brodak 25 I would ask that guy who scored 600 points with that combo at a VSC.

I looked at the VSC results. Joe Gilbert won with a Brodak 25 Ringmaster which weighed only 21 OZ.