ORIGINAL: RCKen
It's kind of like comparing a Chevy Malibu to a Corvette. Yeah, the Malibu is cheaper. But the Corvette is, well, a Vette!!!
Even if you take the difference in price they 55 AX blows the socks off of the Tower Hobby engine. Yes, you do pay a little bit for the OS name. But in this case you are paying more for WAY more engine. All of the new AX engines (55, 75, and 120) set new standards for engines that others will be scrambling to catch up to. I recently did a review on the 75 AX and all I can say is that this engine is a "Stump Puller". It's easily one of THE best engines I have ever owned. The 55 AX is in that same class. There really isn't much competition for it, IMHO.
Ken
That's not really a fair comparison though as you're looking at two different engines with different displacements.
A more fair comparison is the O.S. Ax .46 against the T.H. .46.
There is no doubt that the O.S. is a better machined, more refined and easier to get running out of the box engine...
But that said the two equate well in terms of power.
The T.H. actually edges the O.S. AX .46 out, until you transfer the T.H.'s muffler over in which case there seems to be no difference.
I love the AX .46, but replacing it with a T.H. .46 has resulted in no performance degredation, on the very same plane...
If anything the T.H.'s are also stump pullers and an excellent value for the price.
Yetti831: The T.H. WILL start running out of the box. One mistake I've seen made time and again, is people trying to tune the engine prematurely. Or their planes have fuel system problems which cause the newbie to attempt to correct this via tuning which just futher fouls things up. I've done the latter myself, now I know better so I can set these engines up in a few minutes.
It needs to be run as set at the factory ( or at the factory default/recommended settings ) for a tankful or two, and then tuned a bit with each succeeding tank full.
I've taken them ( and the GMS & SuperTigres, all made in the same factory ) out of a box, and flown them after the first tankful w/o problems, but with reduced performance until the 3rd of fourth tank...
Yes the O.S. doesn't need the same thing so it is MUCH easier for a newbie to get running...