4 blade vs 3 blade props, is this a way of over-propping?

[Per]

And will it harm my engines?
Now i know whey i have EGT gauges...

Anyone have experience with this?

 

[O C Diver]

As with any prop, they are fine as long as you have the correct pitch for the boat / engine / transmission setup.

Ted

 

[FF]

Overproping is the intentional "overloading" (the engine will no longer be able to reach max rpm ) to increase the engines efficiency at a lower ,power setting.

Adding an extra blade is not the best solution as 4 blades are not as efficient as 3, if the 3 has sufficient blade area.

For a cruiser who understands the process a cruising prop can save large amounts of fuel and extend the engine life.

For the uncomprehending it can harm the engine.