Venting props info

[Nitrofreak]

I am looking for info on how to vent your own prop.

I know, I know I should let the prop pros deal with it but I am wanting to experiment with a prop that I took off of my lower unit and replaced it with something else.

Before you ask I have 37 years experience in the automotive field and I know how absolutely critical getting these measurements correct are and how precise you have to be when dealing with them.

I am not saying I know everything about everything please don't misunderstand me...Everyday is a school day I enjoy learning new things and I am looking for a little help in understanding and how to vent a prop.

Any help would be greatly appreciated.

[fishfordollars]

Venting the prop allows the motor to turn up when coming out of the hole. It does not affect the mid range or top end.

Is the prop in question already drilled? If so it is a matter of installing different numbers and sizes of plugs to set it.

If it is not drilled I would contact a prop shop and let them drill it. They then can recommend how to adjust with the plugs.

Personally I would not attempt to drill it. If it's not correct the prop will be useless.

i have a couple of Trophys and a Lazer II (2) that I can measure and give those figures to you if you like. Just be sure, those venting holes have to be located in certain spots in reference to the blade location to work correctly.

Good luck

[Nitrofreak]

fishfordollars,

No I have not drilled it yet but I am wanting to learn or find some info on how this is done correctly.

I do have a basic understanding as to why you vent a prop and some of the options that are out there like variable pitch props and so fourth but I have yet to find any info on how to calculate the correct size holes to drill, how many holes you need to achieve the correct rpms etc...

This boat is not used for top end speed and I am not really concerned with the mid range it has,  Once it's on plane it's a great boat but getting it there is a mess when I have extra weight on board.

The new prop I got for it works better but with a vented prop I don't think it will work near as hard or take as much fuel to get it on plane and if I can figure out the dynamics of this formula...x amount of holes of a certain diameter in this pattern for x amount of pitch = x amount of rpm for my application.

This is something I want to learn how to do on my own,  I have all but built this boat from the ground up and the new carpet is going on it this weekend and it will be close to finished... There is nothing about this boat that I don't want to understand how it works why it works from bow to prop, Just like my profession from head lights to tail lights.

Thanks for the reply...Be safe be happy and have fun

[shortbasser]

I just did a Google search on "prop vent holes" and turned up a ton of information.

Shortbasser

[Nitrofreak]

Thanks shortbasser I will give that a shot.