Dual Prop Good ?

[tigerhack]

What is the advantages of running a dual prop ?

 

[sschefer]

Re: Dual Prop Good ?

What is the advantages of running a dual prop ?

Just to preface this - I don't have them and I've never used them, I have researched them.

Technically speaking, a single blade prop (screw) is the most efficient but very difficult to balance. In theory the more blades you have the closer you should be to optimal. My questions to pro's on the subject pretty much summed it up as worthless unless you have an advanced counter rotational system where one prop turns counter clockwise and the other turns clockwise on a single prop shaft, (mulitple piece).

In every case, the ones that said the average everyday non counter rotational system was great were refering to someone elses boat and not theirs.

 

[TilliamWe]

Re: Dual Prop Good ?

What is the advantages of running a dual prop ?

If you are referring to "counter rotating dual prop" outdrives, such as Volvo Penta's DuoProp or Mercruiser's Bravo 3, then the advantages are: (assuming the same engine as a single prop drive)

1) Less propslip
2) Better acceleration from slow speeds
3) Faster time to plane
4) Lower planing speed
5) Ability to turn either direction in reverse (single prop drives tend to only turn one direction in reverse, and just go straight when you have the wheel turned the other way)
6) Faster cruising speed at a given RPM

 

[mthieme]

Re: Dual Prop Good ?

5) Ability to turn either direction in reverse (single prop drives tend to only turn one direction in reverse, and just go straight when you have the wheel turned the other way)

Huh?

 

[QC]

Re: Dual Prop Good ?

Tilliam is right. Single prop drives with standard props (RH) tend to back better to starboard than port. Very common. I remember by saying to myself "port problem" . . .

 

[slasmith1]

Re: Dual Prop Good ?

If you are referring to "counter rotating dual prop" outdrives, such as Volvo Penta's DuoProp or Mercruiser's Bravo 3, then the advantages are: (assuming the same engine as a single prop drive)

1) Less propslip
2) Better acceleration from slow speeds
3) Faster time to plane
4) Lower planing speed
5) Ability to turn either direction in reverse (single prop drives tend to only turn one direction in reverse, and just go straight when you have the wheel turned the other way)
6) Faster cruising speed at a given RPM

7) better fuel economy

 

[Bondo]

Re: Dual Prop Good ?

1992 regal ambassador 233xl Mercrusier 5.7 alpha 1 out drive.

Ayuh,...

You Don't have that option.....

 

[tigerhack]

Re: Dual Prop Good ?

Ayuh,...

You Don't have that option.....

ayuh....i hear you.

 

[TilliamWe]

Re: Dual Prop Good ?

Tilliam is right. Single prop drives with standard props (RH) tend to back better to starboard than port. Very common. I remember by saying to myself "port problem" . . .

Yep, people who used to drive my boat when they were used to a single prop drive were always amazed that it turned so well in reverse.

tigerhack, you thinking of buying a different boat with a dual prop drive???

 

[tigerhack]

Re: Dual Prop Good ?

Yep, people who used to drive my boat when they were used to a single prop drive were always amazed that it turned so well in reverse.

tigerhack, you thinking of buying a different boat with a dual prop drive???

No i am trying to find out if i can get a dual prop for my single drive.

 

[slasmith1]

Re: Dual Prop Good ?

No i am trying to find out if i can get a dual prop for my single drive.

If it is an alpha 1 you will need to replace the whole drive to do it. Just bring lots of money and everything will be fine.

 

[QC]

Re: Dual Prop Good ?

You can't . . . Must be a Bravo.

Edit: merge this with slasmith's and you have your answer.

 

[derekpfeiffer]

Re: Dual Prop Good ?

I must say I had never even been in a boat with a dual prop drive till I bought mine...but now wouldn't own one without one!!!

The planing time and acceleration in incredible!! handling at low speeds is also very impressive. Also you don't get the port side lift like you do off a single prop drive while hole shotting.

But the down side is you don't get to run those cheap disposable alluminum props like you can on a single prop drive and you have twice as many props to damage. The Bravo three's run pretty warm due to the extra parts/and friction from them. So I just ordered a drive shower for mine because we run it on the river a lot and sometimes will run 45min to an hours without stopping...its a long time for that drive to be up out of the water.