Prop info and help needed!

[rb8484]

Let me first start with saying thanks to all in advance! This is such a great site. This is my first time posting in this section, but I am one that does not know much about props.

Why would you want a 4 blade? pros....cons???

I have a 3 blade stainless prop on the boat now with a 19 pitch. Im not sure if this is the best combo for my boat or not. I dont have any problems with is. It is a 1990 arriva with the 5.7 merc alpha one. It is a 24 footer i/o. I do a little bit of skiing with it and pull some inflatables. I do some boating out on lake michigan as well. I will check out the rpms this weekend when Im out on lake michigan and report speed and rpms.

Also, what is the advantage of a stainless prop over aluminum?? I know the aluminum is cheaper, but why would one want the stainless?? I might get an aluminum one to put on when I am on lakes that I am not familiar with.....that why if i mess up the prop, its not the expensive stainless one.

Thanks again and sorry for all the questions!!!!

 

[hwsiii]

Re: Prop info and help needed!

On heavy boats like yours a 4 blade can raise the boat higher out of the water for more speed and increase cruising speed as well as lower the speed needed to plane.
Aluminum props as a normal course do not have much blade geometry built into them, most people consider them entry level props. Blade geometry can increase speed and performance greatly when you have the correct blade geometry.

H

 

[rb8484]

Re: Prop info and help needed!

On heavy boats like yours a 4 blade can raise the boat higher out of the water for more speed and increase cruising speed as well as lower the speed needed to plane.
Aluminum props as a normal course do not have much blade geometry built into them, most people consider them entry level props. Blade geometry can increase speed and performance greatly when you have the correct blade geometry.

H

I see. So would it be wise of me to look into a blade?? With the increase of the boat higher out of the water,......am I going to loose my hole shot for pulling tubers or skiers?? If I get a blade, should i stay with a 19 pitch?

 

[junior1113]

Re: Prop info and help needed!

four blade rule of thumb go down 1" in pitch to compensate for rpm decrease. what are current wot rpms and speed?

 

[rb8484]

Re: Prop info and help needed!

four blade rule of thumb go down 1" in pitch to compensate for rpm decrease. what are current wot rpms and speed?

I will report back with you tomorrow evening and let you know. I will have the boat out tomarrow.

 

[rb8484]

Re: Prop info and help needed!

Well, I was out on lake michigan today, and it was way to choppy to open her up WOT. So I will have to report back on the RPM's at WOT