Increasing 1/2" in prop. Diameter

[seaboo]

My boat currently has a 14.5 x 19 prop on it (factory prop). The wot rpms are where they should be (actually a lil low but not much). I'm happy with the hole shot and top speed (would like more of both of course, but I'm good with the current set up).

The prop is a lil beat up and I'm gonna replace it. I can get a 15 x (any size) easier and cheaper than a 14.5 diameter prop. If I go this route do I need to change the pitch or is it gonna be ok (I can get a 15x18, 15x19 or a 15x20).

The current prop. is a factory stainless steel one, BUT it is a thin lightweight one (about the same thickness and weight as an aluminum prop).

The new prop I'm looking at is an aluminum prop.

 

[RicMic]

Re: Increasing 1/2" in prop. Diameter

You are very unlikely to notice a 1/2" difference in diameter as long as there are no interference problems. However changing styles, brands and materials can make a difference.

 

[donzi gt230]

Re: Increasing 1/2" in prop. Diameter

If you're changing brands or styles that'll change a lot. IF you were talking about the exact same prop designs, you should probably drop the pitch. You're already on the low side of RPM and increasing diameter will drop it a little more.

 

[RicMic]

Re: Increasing 1/2" in prop. Diameter

If you're changing brands or styles that'll change a lot. IF you were talking about the exact same prop designs, you should probably drop the pitch. You're already on the low side of RPM and increasing diameter will drop it a little more.

It MIGHT drop the rpms, but as he said the current prop is "a little beat up" and switching from SS to aluminum, its difficult to predict.

 

[sethjon]

Re: Increasing 1/2" in prop. Diameter

My boat currently has a 14.5 x 19 prop on it (factory prop). The wot rpms are where they should be (actually a lil low but not much). I'm happy with the hole shot and top speed (would like more of both of course, but I'm good with the current set up).

The prop is a lil beat up and I'm gonna replace it. I can get a 15 x (any size) easier and cheaper than a 14.5 diameter prop. If I go this route do I need to change the pitch or is it gonna be ok (I can get a 15x18, 15x19 or a 15x20).

The current prop. is a factory stainless steel one, BUT it is a thin lightweight one (about the same thickness and weight as an aluminum prop).

The new prop I'm looking at is an aluminum prop.

Check your current prop to see if you have enough space for an extra 1/2". If you're not sure drop a 1/2" As far as pitch goes, stay within 1" since you like the performance of the current one. If anything go down 1 for a slightly better hole shot.

 

[RicMic]

Re: Increasing 1/2" in prop. Diameter

Check your current prop to see if you have enough space for an extra 1/2". If you're not sure drop a 1/2" As far as pitch goes, stay within 1" since you like the performance of the current one. If anything go down 1 for a slightly better hole shot.

A 1/2" bigger in dia. is only 1/4" bigger on the radius, for clearance.

 

[seaboo]

Re: Increasing 1/2" in prop. Diameter

Boat is in the water so I can't check clearance till the weekend, but originally the boat (as an option) could have come with a 15x17 prop so I feel confident that clearance would not be an issue.

I'm ordering from iboats (great price and fast shipping) and they have great customer service so I'm comfortable that if I am not satisfied we can work something out. I think I'll try it and see (maybe by this weekend).