My point was you were quoting these virtual figures around as if they had some real meaning. To calc an engine to run at some RPM that is not verifiable doesn't do any reader justice. What would someone think of your data if they ran out and bought a E45 based on the hypothetical data only to find out they wasted $25-$30 on the prop as the engine won't spin it.... or wrose yet be dissappointed at the perfromacen vs a 50CC engine they could have bought with the same money...
I don't get the "ease to install" thing either... how is the 45 any easier to install than say a DA50?
I'm also not sure I follow the .7 lb wingloading thing... the 45 and 50 weigh almost identical... so if you ask anyone if they'd like to have 10 lbs more thrust on a 15 lb plane for the same price what do you think the answer would be?
(I really don't think it's 10 lbs more... (ir's probably less maybe 5-6 lbs in real life) as you just threw some numbers again at the 45)
I'm really not trying to give you a hrad time, as I'm sure the 45 is a great engine... and Horizon is an excellent company... but to take theoretical data and comapre it to real world data is misleading and certainly has no value to readers.
I would MUCH rather see you get one in, weigh it, spin a couple props on it and report the results. You kind of did the same thing regarding the 58... you really seem to like the engines... so you can best help their potential users by reporting your personal findings instead of comparing theoretical data that may very well not prove out. It doesn't help potential buyers to fairly assess the engines.
Truth is I believe the 45 HAS been out long enough for many people to come on line and say things like "OMG, this thing is spinning a 23x8 at 7,200 rpm... or some such thing... instead I've read basically nothing on the engine which is generally not an overly good indicator that it's meeting or coming close to expectations.
I would expect a powerful 43cc engine to put out maybe 6200-6400 rpms on a 22x8 Menz and an inverted pitts and perhaps 6600-6800 on a tuned pipe... still not anywhere near the 7000+ on a DA50 with stock muffler. They are the same weight, similar physical dimensions and identical in cost...
ORIGINAL: AirTech
Maudib
I don't think many people have much experience with the 45GX so far, being practically a brand new engine on the market. As I mentioned before manufacturers specifications are mostly inflated. So if you want to compare any engine against another one you don't have much "real" data to go with. The most one can do, especially with a new engine is to "guesstimate".
My point in using a 40cc class engine in the GP Yak is a matter of "installation ease". I have a ZDZ 40RV I could have used in this plane, but I am a little adventurous and will like to try something new in this engine class. I am sure the ZDZ will fly the Yak as well, or maybe better than the Evolution, and you can install it fairly easy on the GP Yak.
Probably the easiest engine to install in this model is the recommended Fuji EI-43. BUT what the heck........different strokes for different folks. There is people that will swear by their DA's and I think is more like the Harley against Rice Burner controversy, you know.......is made in America, so it has to be better. And by the way I am not on any one engine distributor payroll. As far as I concerned you can install a Lycoming IO-540 if that's what you like. (It may ruin your wingloading, but the thrust to weight ratio would be out of this world)
By the way I plugged the "real world" data for the DA (23-8 MenzS @ 7100 RPM) versus the same prop at (a theoretical) 6200 RPM on the Evolution. And while the DA shows some 10 Lb more thrust, the thrust to weight ratio difference is only .7 Lb more for the GP Yak wingloading. So...in the final analysis, I am not going to loose any sleep over this controversy.