I exaggerate about the LA46. But the run desired by many is quite rich. Almost old school rich. Tho probably still 2-stroke.
Do you know why? Because I have been telling people the answer for about as long as there has been an internet, including my first SN engine column AND above in this very thread. One of my very first internet posts ever, on the old Compuserve forum, in 1996, explained it.
Really amazes me that many of the experts who speak here have very little to say about tuning a given engine to a given model. What's that about.
It's because you AREN'T PAYING ATTENTION. The reason people are running 46LA's blubbery rich, the reason that there is an entire industry dedicated to detuning the 46LA, 40FP, 40FSR etc is because, for the millionth time, they are *fantastically too powerful for the airplanes they are using them in*. Put a 46LA in a Twister, Nobler, you had darn well better have a way of detuning it because that is far too small for the engine at full power. The only thing different about the 46LA is that you have a decent chance of managing it.
Put another way - many people are trying to put it into airplanes that are far too small , i.e. *not matching the engine to the airplane*.
Hey, you don't have to believe me, do simple math. Take one of these airplanes (like a Twister or something like that) with blubbering 46LAs, time the laps, and compute the speed. Then lean it out to be peaked, time it again. Take the ratio of the fast speed to the slow speed. Then cube it (that's the little button with the x^y on it. y=3). That's the power difference. It will be around a 1.75 to 2.0 or so - so TWICE AS MUCH POWER AS NEEDED. That's why you have to run it very rich.
BTW, here's an idea - if you have twice as much power as you need, maybe you should get one that is half as big. Half of a 46 is a 23 - so maybe a 20 or 25 of similar construction and performance. Like, a 20/25FP or 25 LA.
Yes, more of that terrible egghead stuff, but, oddly, it explains the observed performance almost exactly.
That is exactly and precisely what happened to me out in a field in Gilroy, CA after trying to get someone's 40FP to stop "running away" flight after flight. I have told more-or-less exactly the same story for the entire time there was an internet to tell it on. Like this one (from 15 YEARS AGO):
http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=1916&mesg_id=1916 Note that this issue goes away with piped engines, because you have some control over the shape of the power curve, and you can have the right power wherever you want it. The need to tweak serious competition airplanes carefully for the engine went away bordering on *30 years ago*. That's why we can fly airplanes as small as 585 square inches with a PA65, *we have control over the power*. You don't need to be too careful about "matching". It used to be critical, now it hardly matters, you can make it work.
So don't say that the "experts" aren't talking about it, we talk about it all the time, you just don't bother to pay any attention.
The competitors I see do considerable tuning and tweaking before they feel they've gotten the best out of a given engine/airplane combination.
Of course, because others are going to optimize theirs, you have to optimize yours. It's far more effective and far less time-intensive than it was back in the "good old days", when it was absolutely endless, and the results were almost random. The idea is to *compete*, you have to do things better than the next guy.
This single post proved that you have *no idea* what you are talking about, and have apparently gone out of your way to remain clueless, despite having the necessary information available for literally decades. If you can't be bothered to do even the tiniest bit of research on something that has been common knowledge for 25 or so years, then yes, stunt can be very confusing.
I am perfectly willing to listen to responsible and knowledgable feedback or argument, or honest questions. But when to go out of your way to say that I and the many others who have spent an awful lot of time actually understand what is going on (and endless hours trying to share the hard-won knowledge) are stupid, mock us with these endless snarky "haha, look at the so-called experts, what a bunch of idiots" posts, it's hard to see any constructive point.
In this case, it's turning a very nice and reasonable thread for a guy trying to get current information to he can get started again, into a "Look at me, I am the self-styled iconoclast Dennis Moritz, and I stick it to the establishment, ha ha ha". That's pretty disgraceful, even by your standards.
Ironically you were trying to turn this into an "Joe Bellcrank VS the out-of-touch elite" thread. While the purported elitists were trying to help someone, you go out of your way to derail it.
Brett
Topic: Just some thought on returning to control line... (Read 22963 times)