wots the differance between a 3 bladed prop and a 2 bladed prop e.g 3 bladed prop gives u more talk ect ? and would a irvine .46 be able 2 handle a 3 bladed prop?

3 bladed props can be shorter then 2 bladed props to get the same traction. 3 bladed props are harder to balance then 2 bladed props and that is the exxtent of my knowledge

3 bladed props are used for more power and they give you some more ground clearance. They do give a bit more tourque also.

I don't agree with Pilot Chad, 2 bladed props will almost always give you beter performance on the same engine as a 3 bladed prop. Therefore unless you really need the ground clearance, you are better off sticking to 2 bladed props. [8D]

Ditto with fastsky. Chad is 180 degrees off... 3-bladed props should produce less power and have less torque effects. In fact, some racing models use one bladed props (with counter weight) becasue it is more effecient than a 2-bladed prop. The main issue is that as a blade produces thrust (lift), it produces dirty air (downwash, turbelence, etc.) The following blade works on this unclean air, making it less effetive. The more blades you have, the closer each blade must work to the "bad" air caused by the leading blade. This reduces the effeciency of the prop, which adds drag. The net result is more engine power is used to produce the same thrust. I believe this effect diminishes some with scale, i.e., it is less noticable on full scale, but I may be off on that one.

Engine - this really doesn't matter. Any engine (including your irvibe 46) can spin a prop with any number of blades. The key is to keep the engine loaded properly. Too much load will reduce RPM and cause the engine to overheat. Too little load can over rev the engine and wastes power. I.E., if your engine likes to run WOT at 10K RPM, any prop that produces this RPM at WOT will work.

Sound - Two bladed props are generally louder than 3-bladed. This is becasue typically you would typically size the props such that the engine always ran at a certain RPM for top end. Since you also typically want the model to always have a certain top speed, a pitch change isn't desired. So what is typically changed is prop diameter, with the 3B prop having a smaller diameter. Smaller diameter at same RPM = less tip speed. Much of prop noise is directly related to the tip speed. However, a lot of noise is also related to prop design and materials.

Thrust - becasue of what I described in the first paragrah, 2B props generally produce more static thrust on a engine. Of course, this doesn't have to hold true depending upon prop selection, but in general when switching from comparable 2B to 3B, you will notice a loss of static thrust.

Braking - 3B props tend to have better braking effects, i.e. slow model better at low power. More of the prop disk is filled with a 3B, more drag, etc.