For what it is worth, Brett and a few others have been touting the Skyray / FP 20 as a super combo for some time. To put the ARF Flite-Streak in the same class is high praise indeed from a "top gun". I'd bet the farm he was on 60 X .015 lines, although he didn't say.
The lines were .015x62, as I recall. I didn't remeasure them. I know that in the past 58 was unnecessarily short. When it was set right, the lap times were about 4.8 seconds at the beginning down to about 4.6 at the end, running suction on a clunk tank. Fuel for a full pattern, 10/18 Powermaster (left over from the Team Trials) at about 50 degrees and 15 feet above sea level, was right around 2 oz.
On the topic of the LA, I was primarily commenting on the remote needle. Despite the common wisdom, it seemed to work just fine straight out of the box. That doesn't necessarily mean that they are all good, but I don't see any reason it wouldn't work. It may have been harder to start, although I never found that to be the case with the 15FP or Fox remote needles. This particular LA *was* surprisingly hard to get to start, but it was also brand new, so I don't know if this is a function of the remote needle or not. The run was *dead steady* and very effective. Back to back with the 20FP, with relatively little fiddling, it was unclear to me if the 25 was going to be able to be adjusted to have that just perfect power variation that you can get with the FP and 40VF. The first 4 runs on the 20 also weren't exactly right - I was chasing the needle as the day warmed dramatically and also as the old congealed oil and teaspoon of after-run cleared out of it. Only the last two flights were dead on as far as the needle goes. For the record, for mine, with a suction tank, with muffler pressure, and a clunk, it needed to be set just barely into the 2-stroke.
When I did the extensive tests on the various .15-.28 scheurle engines available in 93/94, almost all of them were capable of giving excellent results and very steady runs -
presuming you put on the correct prop and ran them as intended, i.e. in a two-stroke. The 20FP stood out in that with the right prop it would have that perfect amount of power increase in the maneuvers. The 25FP would do it about half the time, and the 20 was just about every time. Of course you had to hit the needle right, but other than that, it was time after time on engine after engine - at least 20 of them locally. All three of mine ran exactly the same to the point you could predict the rate of fuel consumption change as they broke in. I flew one of them brand new at a contest with no break-in and no test flights. Took it out of the box, hooked it up, fired it up, and flew an official flight for about a 520 - in a 15 MPH wind! There's not a whole lot of engines I would have trusted to be that predictable.
But a little lost in the endless 20FP discussion/argument was the second interesting finding from the experiment - that ALL of the engines I tried were quite satisfactory straight out of the box.
As long as you didn't try to run them like a Fox 35. None needed any aftermarket modifications, Dremel tool "expert reworking for lucky best stunt run", nothing, including the stock mufflers. Get a 4" pitch prop of an appropriate, relatively small diameter, fire up, peak out, back off a bit to keep it from going over the top lean at the end, launch, stunt happiness ensues.
The time has been ripe to re-run similar experiments with current engines with the same ground rules - 4" of pitch, ~11000 launch revs, 2-stroking in level flight, and a Flite Streak or Skyray 35. I am not going to do it, so someone else can take up the torch. If I had to ditch my 20FPs tomorrow, I would start with a 25LAS-RN.
Brett
Topic: Would like line size advice (Read 2784 times)