What propellers are best for my 2X250 Suzuki?

[Highperformance]

I have just placed an order for a 26’ boat. With a dry weight of 1700kg without engines. According to the maker the boat is doing 65knots with 2X250 E-Tec.
My boat will be delivered in May 2006. I already got 2X250 Suzuki to go with it.
The original propeller is a three blade 26” and will probably not get me anywhere close to 65kots.

Also, where can I get this propellers?


Thanks for the advice
Highperformance

[roycruse]

According to my theoretical calculations 51 knots will be your maximum speed with 26 inch pitch props with Suzuki DF250's.

You would need around a 34 inch pitch prop to get that kind of speed and as far as I know they dont make props for that engine in that size and im not sure the engines would have enough grunt to turn props of that pitch even if they did exist.

Even with the e-tecs higher gear ratio you would still need 30" pitch props to get 65 knots. And Im not sure they do props of that size for the e-tecs either.

May be someone makes specialist props for these special high performance applications that im not aware of ???

[qcamel]

Steel Developments in London make and supply very high quality props. Call +44020 8874 7059 and ask for David

Ollie

[Highperformance]

Checked out http://www.steeldevelopments.com/
Max 28". Not enough for me I believe..

[qcamel]

speak on the telephone, my understanding is that they will source/make props to your requirments...

[Actionboat.dk]

Roycruse I don't agrey on on your mat. on prop. What slip are you config.
I'm doing 62,6kn with and rev4 23* with give me a slip of 3%
normal we say more than 15% change prop..

BR Jan

[roycruse]

Yes I was using 15% as slip - I was being conservative - I always try work out worst case senario and then any extra knots is a bonus.

Sorry I should have given the slip % in my post

3% is very good - what weight is your boat

[roycruse]

Using a more optimistic 5% slip

26" props on the suzukis will give 54 knots and to achieve 65 knots you would need a 31" prop.

On the E-tec 250's 65 knots would require a 25" prop.

Actionboat arew you refering to E-tec 250s or your verado 275s when you give your figures

by my calculations a 23" prop on a E-tec 250 which has max rpm of 5800 and a gear ratio of 1.85 would give you - with 3% slip 57.57 knots

This is the calculation

(RPM X PITCH) / (RATIO X 1215) = MAX THEORETICAL SPEED (NO SLIP)

(5800 X 23) / (1.85 X 1215) = 59.35

Then take off 3% = 57.57

[Petrov]

We are using a lot of REV 4 and they are great props, we will now test the Hydromotive 26 (also 4 blade) on the 250 SUZ, the guys that are helping us with testing of props have been driving the Hydromotive on several boats with good results, i will keep you updated with how they work out as soon as the ice is gone

[Actionboat.dk]

Originally Posted by Petrov

We are using a lot of REV 4 and they are great props, we will now test the Hydromotive 26 (also 4 blade) on the 250 SUZ, the guys that are helping us with testing of props have been driving the Hydromotive on several boats with good results, i will keep you updated with how they work out as soon as the ice is gone

Hi Petrov. I have a pair of hydromotive 28 (4blade) you can borrow or buy if you want?

[Actionboat.dk]

Roycruse. I only have verado's now. 6300 rpm
I come to the same figures as you on the mat. I use TSpeed ver 1.1

I don't know if I can athach it to the group.

BR Jan

[Petrov]

Thanks Jan but i allready got 26 and 28 pitch, do you have the new Hydromotive with exhaust before the blade or the model before?

[Actionboat.dk]

Hi Petrov I have the new one with the HUB and the ring if you don't want the gas to come out before the prop.
BR Jan

[Petrov]

Oki thanks;

Its easy to plug them.