ORIGINAL: Brandon15
Not sure if I should post this here, but I'm gonna....
TOM,
I have an older version (K or L can't remember..lol) 3W 60 and 3W 40 both are the ones with long crankshafts. Both were bought brand new at a SwapMeet a few years back ($450 for both....hard to pass up!). I have quiet a few tanks through the 40 and just got around to running the 60 about 5-6 tanks through it. Anyway I was just wondering if you could suggest some prop sizes for each engine...I've been running a TBM 22-8 on the 40 and a XOAR 23B on the 60, but I also have a 3W 24-10 I'm gonna try on the 60. Any info would be appreciated. Also I wish some of these light 50-60cc engines had the power that 60 seems to have!
First, don't plan on high RPM numbers with the 3w's. Shooting for them shoots yourself in the foot. Look for wider blade props that are extremely stiff. Such as a laminated prop. PAU and XOAR both make some of the better props of that type. They will cost more but you
will notice the difference on the 60. I think the better laminated wood props work better than some of the slimmer carbon ones. The 60 will swing the 24 but pay attention to the cooling flow through the engine. You might want to try an 8" pitch with a 24 to see how that work out. The type of flying you're doing will determine the size prop to a great extent. If you can maintain good throttle response the engine can handle the prop. That throttle response is helping you know what you need to do with the tuning to keep everything in line.
Just remember that a general rule is that greater diameter equals more thrust while greater pitch equals more speed. Then you have the other end where a smaller diameter with a lot more pitch equals more speed but it takes longer to get there. 3w's can handle an inch more diameter generally.