Cap'n Morgan wrote:
jeffd wrote:
What prop are you running on your 5.0 SS?
I am thinking about swapping it out for a PowerTech RAS 19p 3-blade that is 14 1/4" diameter. It is supposed to be a better blade.
-=jeff
Curious where you got the info that it is "supposed" to be a better blade. Sounds like sales hype. What is the alledged blade improvement, is it in the Rake, Skew, DAR, blade thickness, pitch line ? Also, you say you "think" you are getting slipage. Do you mean cavitation? Ventilation ? Prop hub slippage ? Please explain.
You touched on several items - larger diameter, cupping, rake, and blade thickness are among the supposed improvements in this other prop I am considering. Admittedly, the Michigan Wheel Apollo is a lower-end prop. The blades are thin by comparison (that is when compared to the RAS unit) and the diameter of this prop is a bit smaller than the aluminum that was on the boat as delivered.
I *think* I am getting some slippage due to the reduced top-end speed as registered by the in-dash speedo (yeah, I know it isn't accurate, but as a basic instrument, it does give a high water mark at the very least).
Also I do think that the reduced surface area by virtue of the reduced diameter has an impact on the prop's overall performance and efficiently. Slippage is not exclusively indicated by cavitation. Slippage can be thought of as the props "traction" in the water. Is this not a valid assumption? My vendor is willing to let me try various props, so why not? I am just wanting to hear about what other boaters are using so I can make an informed decision.
Thanks,
-=jeff