Originally posted by Ed_Moorman
Actually, Thunder Tiger engines tend to be heavy. OS makes very light 2-strokes. In most planes, and for most fliers, 2 or 3 ounces doesn't mean very much, but on a fun fly plane, you'll get better performance with a lighter engine. The TT .46, from their web site, weighs 15.8 ounces and the OS .46FX, 13.2. That's 2.6 ounces, which can mean a lot in a high performance plane. I own a TT .46 and it is a great engine, it's just not the lightest. I also own an OS .91FX which is lighter than just about any ball bearing .61 and produces tons more power.
When it comes to 4-strokes, the TT .91 is a real heavyweight. It weighs nearly a half pound more than a Saito .91!
Wow, it always amazes me what people will skim over when reading information. All the values for TT engines are with their mufflers. OS for some reason feels the need to publish the weight of their engines without their mufflers (I'm guessing since most OS flyers fly sans muffler
). The TT Pro-46 is right around 16oz (measured on a fairly accurate postal scale). My OS46FX is 17oz with muffler. I just weighed one last night.
I've heard that the TT 91 FS is a bit portly for an engine of it's size, but then again, it'll turn a bigger prop faster than both the Saito and OS 4 strokes (although not as fast as the YS which is also a bit heavy).