Finding a good 1/2A speed engine is not a simple task.
There are lots of high-RPM Euro combat engines that show promise but fall short on the top end. When a good one used for proto speed, 85-90+ mph seems to be about the best while the occasional GZ/CS will run much faster. The workmanship on the Cyclon and Fora is excellent, while the GZ has problems, so you never know what you will get. The combination of all this is that unless you are able to make your own engine you still have to somehow deal with the limitations of the current ones.
The Picco Corp. has come close to providing an excellent 1/2A engine, (P-Zero) it however is too large of a displacement for control line speed. At .504 ci, it's just a bit too chubby to be used. The workmanship however is top of the line and represents Picco very well. Originally manufactured for the RC car market, the engine proved to be too powerful for most, the comments I did find on various car sites warned of too much power, I wondered out loud how this could be so.
While reading the Delphi speed forum, I stumbled on to two of the little monsters and thanks to Graham Collins, soon had them in my possession. I later began to appreciate just how difficult it is to find the P-zero as I tried to find more for other speed flyers with no success. Perhaps Mr. Picco will read this and make a few more available.
The first hurdle in this project was which was the best method to reduce the displacement? My first thought was to lap the piston to a smaller diameter and rechrome the liner to fit. Having been out of speed for some time, I was unaware of all those who are no longer around to do this very specialized work. After a long breakfast counseling session with "Rock Star" Paul Gibeault, and phone calls to "The Oracle" my old friendHenry Nelson, it seemed that only one person could adequately chrome and fit the liner, Tim Gillott. Tim however is difficult to find, and after several attempts to phone him I began to think about the possibility of destroking the little problem. The more I thought about it, the more I liked the idea of not changing the piston and liner fit by Picco. More counseling from Jerry Rocha who suggested I contact Doug Galbreath to see if he would be interested in doing the work. Doug as many know is an expert in 1/2A engines and a source for Cyclon engines, custom cylinder heads and more. After a few e-mails, the engine was sent to him for evaluation, the result being a very nice rework and destroke to allow this engine into the control line speed events. Doug had to make some tooling in order to accomplish the work, the results seem to be worth it. Additionally, Doug makes precision needle valve assemblies as shown in the pictures.
Since the engine is made for RC cars, there were some of the things this conversion needed:
The stock engines used a "turbo plug" that would give a wider range of heat elements but I opted for the Nelson plug configuration.
The engine has been run using a 4.5x3.5 APC and 25% nitro with static RPM of 32,000.
This, according to Doug, is stronger than the Cyclon. I'll follow up when the new proto ship is complete and a few times have been recorded.
-- Ken Burdick
This page was upated July 26, 2009