"What you are trying is kind against what you are trying to achieve."
Sorry Dan but I'm not sure I understand your comment. I have tried various 11" and 12" 4-pitch props, both narrow and wide versions, and the wide-blade 12-3 BYO seems to pull the Vector better while keeping the speed in check. And I know the longer 64' lines is also contributing to a more reasonable lap time. My specific experience is the prop pitch is far and away the predominant factor affecting the overall performance with my heavy Vector.
I am a relative rookie to this hobby and don't have the skills or tools to re-pitch a prop. So, I go with what I can find commercially. A 3 vs 4 pitch is a big change (compared to 5 vs 6 for instance). And so far, BYO is the only 12" 3-pitch prop I can find.
I am also a long way off from being able to perform all pattern maneuvers. I only recently started learning the OH8. I also have the luxury of flying with an expert buddy and I will also get his opinion once he flies my model.
Well, you said you went to a 3" pitch looking for more RPM in order to make more thrust. With the BY& O, you probably have about half again more blade area than what you were using, maybe more, and that tends to offset the reduced pitch that would have freed up the engine. The BY&O prop is a good prop. It's origins go back to the ignition days when they were just called Y&O for Yates and Orwick. Those names are familiar to old timers. They produced the props up into the 60s' I think, maybe later. I have collected several in many sizes that are Y&O. Then when the classic/vintage movement started , and gentleman named Clarence Bull (Bule??) acquired the tooling and added his initial to the from of the name, creating BY&O. Clarence passed away and John Brodak picked up the line and improved some things with the help of Jim Hunt, Bob's Dad, and then Brodak has added some to the line. For the most part, they are primarily paddle blade shaped because they were developed at a time when most engines ran 8 to 9,000 RPM, so more blade area for more thrust. When you get up to that 10,000rpm range they can add a lot of load to the engine. You said you barely got to 10,000. A modern 11 to 12-4 will push 11,000 at least on a LA.46. So in short, you don't want to just take pitch itself as gospel and all props will perform the same at that pitch. Blade shape is important , especially the tip shape sometimes. I suggest saving your money and buy a good pitch gauge as you accumulate a prop inventory. With the way things are, there are fewer and fewer off the shelf wood props available. If you learn to rework props, that opens up a lot of options for you. Prather pitch gauges are out there and can bring a high price but deals can be found. Jim Lee carried a pitch gauge that will also measure left hand props. The pitch gauge, a balancer set up, a pair of dial calipers, and a good selection of sanding blocks are all you need. The price of 3 or 4 carbon fiber props will easily get you there and you will always have it. The Thunder Tiger 11-4.5 that everyone likes for the LA.46 isn't in production any long, I think, but may be some stock out there in various places. No matter, because if you can cut and carve a wooden copy of the same prop, it will work just as good and be about 3/4 ounces lighter!! I have been experimenting with this most of this past summer and have had really satisfying results!!
Type at you later,
Dan McEntee