This is interesting as far as how much hype these MT 50 engines are getting. People are getting excited because it is something “New” in the market hoping that it will be something different. Well, I did some research on the engine and the manufacturer (Tomy RC) and I found that all he has done is machine the casing. In fact the rest of the parts come out of the cheap Chinese moped type bikes. There is no innovation here other than assemble part together. As far as some of the claims that I have been reading about aerospace quality materials… Yeah! The claims on some of the advertisements that are out there say that this engine was specifically designed for RC in mind. Perhaps assembled, but not designed.
At this point I am already skeptic since some of those BOLD statements have been disproved. Take a look at the following links and you be the judge.
This is the head of the engine. You can see it at this link http://www.scooterparts4less.com/web...ylinderKit.htm
Look at this engine! Does this look familiar?
http://www.pocketbikeparts.com/Photo...ode=CGEN302226

The cool blue looking head is nothing more than a choice from one of the yellow, red, or silver heads offered in a mini bikes upgrade kit. You can find this at this link.
http://www.pocketbikeparts.com/product_p/cgcy302100.htm

As you know the MT 62 is nothing more than a G62 on an electronic ignition conversion (nothing special)
The MT-42 is I have been told that it has tons of vibrations and the back plate that mounts the engine on an airframe eventually shears and shatters in multiple pieces. You can imagine what can happen to your model if you fly one of your planes with this thing….
As far as the service I understand that some gentleman that has experience in fixing engines will be doing the repairs (Cunningham), but from what I understand he has reached a retiree age. He might be working for a couple more years, but I wonder for how long in the long term? How long do you think the long term service will be?
The MT 50 seems to have some serious twisting moment potential concerns due to the way the head bolts on the casing. Those long bolts and how they attach to the rest of the setup might introduce twisting and shearing moments especially after the head will reach operating temperature. Especially when the head will expand due to heat, the bolts will apply asymmetric force ultimately distorting the head. I wonder about the long term reliability on this engine.
As far as the MT-57 so far as for what I have seen and read it seems that it has some good potential, but it is too soon to make a judgment call since it has not been in the market yet.