Solas prop

[MerryFisher]

I think there are still Solas distributors in Sydney, one in Mona Vale not far from me.  As to motor height I can rule that out as there's no cavitation even on hard turns with the motor trimmed correctly. 

[zmk1962]

When you talk about the effect of turns on your prop you are probably thinking about ventilation- sucking in air into the prop. That is different to cavitation. Prop cavitation occurs when very low pressure is created at the front of the prop blades - where water enters the blades. This low pressure makes gas bubbles “boil” out of the water reducing grip and thrust. Some reasons cavitation can occur are if the prop blade angle is to sharp for the revs (overpitched) or if the motor is mounted  too high and not getting enough water flow to the front of the prop. 

Ventilation and cavitation are often confused but they are two different phenomena- both damaging. 

https://uk.boats.com/how-to/propeller-cavitation-propeller-ventilation/

Cheers Zoran 

[rozza_b]

On 10/13/2018 at 10:41 PM, MerryFisher said:

I think there are still Solas distributors in Sydney, one in Mona Vale not far from me.  As to motor height I can rule that out as there's no cavitation even on hard turns with the motor trimmed correctly. 

as i said though mate still get the height checks if the motor if its to low it will cause dramas as well, believe me i had a problem with mine just like this, motor was way to low and i the prop was wrong, fixed both issues and it sorted my problems out a lot 

[zmk1962]

Hey @MerryFisher ..I would love to hear how this has progressed?  Lots of learnings to be gained for raiders from each others experiences.

Cheers

Zoran

[MerryFisher]

I've got a new prop. Yamaha OEM alloy 13 5/8 14P. Still waiting for a nice day to load the boat up for a test.

[zmk1962]

AWESOME... Saturday looks ok .... I'll be finally going out after a looooooong dry spell.

Best of Luck with the new prop - hope it gets that nice hull of yours to do what you want!

Z

 

 

[Fishop]

16 hours ago, MerryFisher said:

I've got a new prop. Yamaha OEM alloy 13 5/8 14P. Still waiting for a nice day to load the boat up for a test.

4 blade or 3?

 

[JonD]

Before buying any prop consult solas, they will want to know what prop you have, what engine and what its max rpm is as well as what rpm you are getting. Going from alloy to stainless often means a drop of pitch by 2, with a 4 blade prop the pitch reduction is even more. Solas are extremely helpful and will exchange props if needed but from my experience they've always hooked me up with the right prop first time. 

 

[JonD]

20 hours ago, MerryFisher said:

I've got a new prop. Yamaha OEM alloy 13 5/8 14P. Still waiting for a nice day to load the boat up for a test.

 If it reaches the max rpm to easy and you need to go bigger, I have a 13 1/2 15p K  spare which doesn't allow my engine to reach max rpm, the solas stainless 13x13 does but I like having a spare alloy when on remote trips.

Edited October 26, 2018 by JonD

[GoingFishing]

22 hours ago, MerryFisher said:

I've got a new prop. Yamaha OEM alloy 13 5/8 14P. Still waiting for a nice day to load the boat up for a test.

Good luck mate ! Keen to hear how it goes for you

[MerryFisher]

Finally got a chance to test my boat out with 4 people on board. The new prop with slightly larger diameter and lower pitch performed better in the lower rev range up about 15 knots where the boat planes cleanly. This would be the prop I'll be using for high load and when it's choppy outside and you need that mid range performance. The 131/2 15P prop does however give slightly better cursing economy under flat condition. I'm getting 2.1 km/L with the new prop and 2.2-2.3km/L with the 15P for cruising at 18-20 knots. So is the factory setup is ok for cruising the harbour, it's just that I needed more midrange performance when things get rough outside.

[zmk1962]

Yup its all about the thrust developed to get you up on a plane. Sounds as if you're happy with the new prop performance with a load on board.  Thats a great outcome.

Personally I would keep that prop on all the time - yes you lose about 10% economy based on the numbers you quoted, but that buys you the performance that can handle offshore and whatever change in conditions or change in load is thrown at you.  Seems an acceptable compromise. 

Time to get out there - the flathead are biting!

Cheers

Zoran

PS - thanks for the update !

 

[GoingFishing]

Hi mate

Glad to hear your happier with the performance.

Did your holeshot improve ? As from memory your original concern was not about cruising economy it was about the long time it was taking to get on plane

 

 

[Fishop]

On 11/1/2018 at 11:22 AM, MerryFisher said:

Finally got a chance to test my boat out with 4 people on board. The new prop with slightly larger diameter and lower pitch performed better in the lower rev range up about 15 knots where the boat planes cleanly. This would be the prop I'll be using for high load and when it's choppy outside and you need that mid range performance. The 131/2 15P prop does however give slightly better cursing economy under flat condition. I'm getting 2.1 km/L with the new prop and 2.2-2.3km/L with the 15P for cruising at 18-20 knots. So is the factory setup is ok for cruising the harbour, it's just that I needed more midrange performance when things get rough outside.

Pretty much the same boat I am in (excuse the pun).  My 3 blade works fine with 2 people on board, but struggles with more than 4.  Sounds like a 4 blade down a pitch would be perfect for cruising with a bunch of mates or camping trips when the boats loaded up.