Vent holes on an I/O?

[sharps45]

These forums are fascinating. I'm learning just enough to be real dangerous. I'm curious about vent holes in props. I've gone over the forums and there seems to be a disagreement about their use on a I/O drive. Specifically a Volvo Penta with 250 HP. Could I get some more info from the experts? I'm really intrigued by this. thanks

 

[WillyBWright]

Re: Vent holes on an I/O?

IN GENERAL, I have found that vented props on 4-strokes of any kind are counterproductive. Sterndrives especially. Many have plugs available, but the ones with vents are typically designed for outboards with Bow-lift characteristics. Sterndrive stainless props are designed with Stern-lift characteristics and few have vents. That's not to say this is a hard and fast rule, but I've seen few if any exceptions, especially regarding sterndrives. However, competition skiboats with multiple outboards do indeed benefit from using sterndrive props.