14x19 stainless 3 blade vs 14.5x19 aluminium

[Rake722]

Hi all, I have been offered a stainless 14 x 19 stainless prop for very good money to run on a bayliner Capri 1850 fitted with a 3.0LX motor.

the original prop is 14.5 x 19 and I’d like to ask what the effect of the 14 would be ?

is it suitable ? What would the trade off be ?

use of boat is general tootling and some wakeboarding

thanks

ron

 

[Texasmark]

Prop designs are different for different reasons. Take a Ballistic regular prop of a diameter and pitch and check out an XL of the same dimensions. The diameter may move around as the area of the blade is changed and the XL has a lot more blade area than the non XL of the same size.

Other thing could be due to a prop of a given dimension with more "Rake" (bending of the blades toward the rear after the prop material leaves the root). Rake is used for bow lift on bass boats to aid in getting them on the "Pad" for top speed. General use props usually won't have much rake and the diameter could/would be slightly larger.

You can't compare bare pitch and diameter and expect to get a correlation. It all depends on the specific props. Same manufacturer, same model, then you will have the same numbers. Change model or mfgr. and you will/could have totally different performance.

 

[Leardriver]

Bigger diameter and blade surface area help harness bigger HP without slipping. You don't have a nasty motor to tame, so the difference would be minimal.

 

[JimS123]

If you're now running in the low end of the specified rpm range, the SS will probably hurt your hole shot and you won't be happy.

If you're now running at the high end or are over-revving, the SS prop will probably dial you right in perfect.

Find out the exact brand and models of the props and enter the data in Mercury Marine's "prop selector" program. That will provide the most definitive answer.

 

[achris]

Hi all, I have been offered a stainless 14 x 19 stainless prop for very good money to run on a bayliner Capri 1850 fitted with a 3.0LX motor.

the original prop is 14.5 x 19 and I’d like to ask what the effect of the 14 would be ?

is it suitable ? What would the trade off be ?

use of boat is general tootling and some wakeboarding

thanks

ron

Hi Ron. Need to know a few things. What is the performance you're getting with the current aluminium prop? And are both these props the same manufacturer? (If you know the model names, even better). If they are Merc props, it's likely the ali is a 'Black Max', and the SS is a 'Vengeance'. Oh, and blade counts on both (3 or 4).

Performance figures should include, what the WOT revs are, the GPS speed of the boat and the load (number of people).

Also, if you want any changes what you're looking for.

I can only speak for the Mercury produced props (Black Max, Alpha 4, Vengeance, Versura, Mirage, Laser, High 5, etc), but a change from aluminium to SS, with the same pitch will produce pretty much the same performance. The advantage of the SS is the thinner blades, making them a more efficient propeller, and the blades are stronger. They are also have great 'bling' value.

Chris......

 

[Rake722]

Thanks Chris and all.

as the boat is new to us and we are fixing it up we have no idea of current performance.

tje aluminium prop just looks like the standard 3 blade prop.
the stainless is a quicksilver is 48-73980 A5 19p if this helps ?

 

[achris]

Thanks Chris and all.

as the boat is new to us and we are fixing it up we have no idea of current performance.

the aluminium prop just looks like the standard 3 blade prop.
the stainless is a quicksilver is 48-73980 A5 19p if this helps ?

The SS is a Merc prop. A very standard SS before they called them 'Vengeance' (so it's fairly old). If you look closely on the ali, either on the hub between the blade roots, or take it off the drive and look at the ends of the inner hub, you should also find numbers similar to those on the SS....

Without knowing the current performance, unless the SS is REALLY cheap... I'd be getting an accurate tacho and a GPS (even an app on your phone, like GPSTest) and seeing how the boat runs to give yourself some 'benchmarks' to judge against.

Chris........