ORIGINAL: jimmyjames213

my ax55 works fine, makes a ton of power but lags in the midrange, which isnt noticible in a sports flying model (where the ax55 is in now) but i had it on a 3d plane and the ax55 was horrible, would lag right were i needed to hover which was a PITA.
now thats its on a sports model the engine hasnt died on me at all, it wasnt as reliable in the 3d plane which was one reason i switched it. i think my problem was i didnt break it in well enough before trying to big of a prop (12x25x3.75 and 13x4) now thats its swinging a 11x5 the engine is much happier, im going to switch to a 11x6 soon which should be the perfect match, after another gallon or so and the ax finishes breaking in i have no doubt the midrange problem will get much better, then i may throw it back on the 3d plane

the gms .47 is another great engine, to bad its on backorder [], it transititions very smooth which is important for 3d (its what i replaced the ax with) it isnt as powerful as the ax but it will still take a 4.5 lb plane vertical like it was a rocket
the magnum 52 is a great engine once you put a few gallon through it and fine tune it. its a PITA at first to get the idle set right but once its up to speed it will easily keep up with the ax55


the real key to 3d is put a engine you trust on your plane. make sure you have put a few gallons through in a sports model. i made this mistake and will never do it again.
power is important as 3d but nowhere near as important as reliability. the ax55 is not reliable with a 3d prop until it has a few gallons through it.

may i ask what 3d plane, if its the mojo .40 or similar then any .46 is more than enough power, the gms i put on mine makes the plane a rocket w/ a 12.25x3.75 prop
so take that engine off your trainer and stick it on your 3d plane, throw the new engine on it and fly for a few gallons, then throw it on the 3d plane.
i crashed my mojo at least 10 times until i learnt this lesson (luckily the gear took the hit most of the time)