Solent Cruise - Sat 9th Feb - Page 6

whisper · 10 February 2013, 18:08

Manual says revs should be between 5600 to 6200.

Here is the prop list:

http://www.suzukimarine.com/~/media/...llers_PDF.ashx

PeterM · 10 February 2013, 18:13

Quote:

Originally Posted by whisper

I'm using a suzuki 3 x 14 x 21 Alli normally revs to 6k but tried trimming out at wot a bit more than usual as it was flat calm, went up to 44 knots and 6.4k

Thinking about a 3 x 14 x 22 Stainless Steel.

AJ's running a 4 blade SS....

While AJ won't like it..I think whispers 3 blade gives him the revs/speed over AJ.

AJ had the edge on pick up at you'd expect from a 4 blade prop.

I'm not sure it would be healthy to run the engine at whispers revs for to many seasons...

AJ of course has more dials and blue tubes which makes up for it.....I'm 100% on the fence.. ;-)

whisper · 10 February 2013, 18:17

Quote:

Originally Posted by PeterM

While AJ won't like it..I think whispers 3 blade gives him the revs/speed over AJ.

Say no more

jambo · 10 February 2013, 18:17

Quote:

Originally Posted by whisper

I'm using a suzuki 3 x 14 x 21 Alli normally revs to 6k but tried trimming out at wot a bit more than usual as it was flat calm, went up to 44 knots and 6.4k

Thinking about a 3 x 14 x 22 Stainless Steel.

AJ's running a 4 blade SS....

Yep thought about changing to a four as they are better balanced. Your change will be interesting have to keep as informed as to the changes>

whisper · 10 February 2013, 18:22

I know that 1" pitch makes around 150 - 200 RPM difference but what changes in RPM will I see if I move from Aluminium to Stainless Steel.

PeterM · 10 February 2013, 18:25

Quote:

Originally Posted by whisper

I know that 1" pitch makes around 150 - 200 RPM difference but what changes in RPM will I see if I move from Aluminium to Stainless Steel.

Should rev higher for same pitch..hence the up in pitch ... ;-)

whisper · 10 February 2013, 18:29

Quote:

Originally Posted by PeterM

Should rev higher for same pitch..hence the up in pitch ... ;-)

3 x 14 x 24 SS then?

PeterM · 10 February 2013, 18:37

Quote:

Originally Posted by whisper

3 x 14 x 24 SS then?

My feeling (which counts for nothing)...is 24 would be to high....maybe 22 or 23....

biffer · 10 February 2013, 18:44

The most efficient prop is a single blade but obviously no balance, the less you interrupt the water the better it will work, there is cupping, feathering and polishing which will all help to tune the prop, highly polished props cause less cavitation because there are smooth cupping will make them grip better, feathering causes less cavitation as the edges are sharper

whisper · 10 February 2013, 18:50

Thanks Biff, any idea of a make I should look into?

PeterM · 10 February 2013, 19:15

Quote:

Originally Posted by whisper

Thanks Biff, any idea of a make I should look into?

+1 what Biff said..shinier the better ....

Ahem..thread drift?

- but just watched videos with laptop hooked to TV.. AWESOME !!!

biffer · 10 February 2013, 19:51

Quote:

Originally Posted by whisper

Thanks Biff, any idea of a make I should look into?

Not been into outboard props for a long time, stainless doesn't flex like Ali ones, I've got someone local to me that I use for balance and ideas, it's witchcraft to get a propeller right, the big bronze ones on the race boat are 99 % efficient but I've spent weeks on them, cleaning, filing, and fiddling about, years ago I used to cup and balance them myself

longjohn · 11 February 2013, 01:14

Quote:

Originally Posted by PeterM

Thanks..no idea why it's not watchable on mobile devices.... :-(...

Maybe the music?... Can't think of another reason and can't change the settings...

I don't think it's the music - it's either because its in WMV format or the resolution is too high or is there a setting on upload to YouTube to allow mobile device playback?
Most Mobile devices like 720p or less resolution and .mov or mp4 formats

AJ. · 11 February 2013, 19:44

Quote:

Originally Posted by PeterM

While AJ won't like it..I think whispers 3 blade gives him the revs/speed over AJ.

AJ had the edge on pick up at you'd expect from a 4 blade prop.

I'm not sure it would be healthy to run the engine at whispers revs for to many seasons...

AJ of course has more dials and blue tubes which makes up for it.....I'm 100% on the fence.. ;-)

Ha very diplomatic PeterM!

As much as it pains me I do agree. However I am maxing at 6100 rpm and on that trip hitting 41knts while the prop on Whispers is going to 6400

I have the 3 blade ali also but find the four blade ss is much better for grip when going in circles and getting out of the hole. Which for most boat use in the UK is probably best for being more reactive to our usual lumpy sea state.

There was a chap on here called Biggles a while back and when I was searching through the threads on here for RC585 he had a 585 and got a ss from Ribshop which he said was loads better than the standard ali. I did call Ribshop about 12 months ago to see if they could remember what they provided but unfortunately they couldn't

whisper · 11 February 2013, 19:50

I was only going 44 knots at 6400 for a few seconds as I was one up and trimmed it right out with the tide. Normally it does 40 knots at 6000rpm with the family on, but if I trim out the prop slips.

So I need to find a prop that fixes the slippage

Chris · 11 February 2013, 20:00

Quote:

Originally Posted by whisper

I was only going 44 knots at 6400 for a few seconds as I was one up and trimmed it right out with the tide. Normally it does 40 knots at 6000rpm with the family on, but if I trim out the prop slips.

So I need to find a prop that fixes the slippage

Is the prop slipping or is the engine too high on the transom? Where is the ventilation plate at the moment in relation to the bottom of the hull?

I like quicksilver props and the Mirage has worked out really well on the Honda however each setup is slightly different so I would research what people use with your boat engine combo and what works well.

whisper · 11 February 2013, 20:30

The prop is defiantly slipping, it's like it's easier to blow water out the back than push the boat along, only happens if you trim it out too far in mid range acceleration with a few people on board.

jambo · 11 February 2013, 20:43

Quote:

Originally Posted by whisper

The prop is defiantly slipping, it's like it's easier to blow water out the back than push the boat along, only happens if you trim it out too far in mid range acceleration with a few people on board.

Alex PM Ian Brown IBWET on here he has exactly the same rig as you very knowledgable and keen to share his experiences. Worth contacting.
J

PeterM · 11 February 2013, 20:45

Quote:

Originally Posted by whisper

I was only going 44 knots

Only

..its not exactly crawling along !

whisper · 11 February 2013, 21:13

Quote:

Originally Posted by jambo

Alex PM Ian Brown IBWET on here he has exactly the same rig as you very knowledgable and keen to share his experiences. Worth contacting.
J

Thanks

but don't tell AJ