I have been flying with 2-2-2 engine run setup for the past couple of years and it痴 all right. But lately, I have an engine that runs 4-2-4 ish that feels good as well.
So, generally speaking, which one is easier to fly? Or is it a matter of personal preference?
Generally it is much, much easier to fly a low pitch/high rev engine, which is why it was almost the only system used for 25-ish ye before electric came along. Whether it is a a constant 2-stroke or not, it's the low pitch and associated "high" revs that made it work. The reason is that you have so much better speed control/speed recovery that you can make mistakes and recover much quicker. It was so much better that it completely revolutionized the event.
Classic 4-2 engines at low revs, if you make a mistake you might have to wait until the two level laps to fully recover, and they were functionally obsolete almost 30 years ago.
The other issue with the 4-2 break is that keeping it exactly right was both critical, and difficult. There are so many tricks and techniques you had to know to make it break the right amount at the right time, and even if you managed it, it wouldn't stay that way for long. The engines were also pretty crude, for the most part, you couldn't take a setup on one and use it on the other with any chance of success. People would routinely carry two engines and boxes of parts, not to mention boxes of different propellors for different conditions. I would also note that the 4-2 break era spawned 99& of the barnyard bullsh*t "stunt lore" that still cripples peoples efforts today. You would certainly learn something in the effort - and most of that was counter-productive.
In the days the everybody ran 4-2 break engines, the performance was so marginal that the person who had their engine run right when it counted (whether by skill or luck) had an overwhelming advantage and usually won. Of course, the highly-skilled had a better chance of having that happen, but there was always a huge random factor, since what worked 10 minutes ago on a practice flight may or may not work again on the offiicial.
And to be entirely fair, when people finally got around to the ST60, that was the first time you had *any* performance margin, which reduced the criticality of having everything perfect, so for a very brief time that was probably the best solution - if it hadn't already been discontinued. Then a few years later Rich Tower and company discovered how to tame schnuerle engines, Bob Hunt demonstrated it, and various others got a grip on it (particularly Paul Walker) and getting enough dead reliable power hasn't been a problem. That was in the late 80's, ** 36 years ago **.
The only downturn with that 4-2-4 run is sometimes when the 4 is too slow, I値l get a really strong power gain when the nose is up to the point it痴 hard to predict and to handle.
Yes, exactly. Knowing what to do to fix that sort of behavior (which may or may not appear and disappear at almost random) is quite non-trivial and no one I know ever really mastered it (and I know a lot of guys). Even if a piped low pitch/high rev flew exactly the same as a perfect 4-2 system, it would still be better because of the lack of endless fiddling. The fact that it gives you vastly better performance is just a bonus.
Electric is the next big step forward, probably not as completely transformative as piped engines running low pitch, but still an improvement that makes it still easier due to the absolute repeatability, and significantly better speed control.
Brett