2 outboards vs 1

[korey88]

hey i wondering if using 2 small engines is better than 1. i realise turning and reliability is better with twins but will 2 50hp go as fast as a single 100hp for instance, the speed factor is my main concern!

[88fishframe]

Two engines give a bigger prop area and can be more efficent in that regard. However, speed is limited by your boat hull. Is your hull twin or mono? What is the max engine weight for your transom? The only way you will really know the 'speed' question is by trying both options. And then, you will need to try 2 stroke vs 4 stroke vs EFI vs DI. If your talking speed, spend the biggest bucks you can on the biggest motor your boat is rated for, go for an EFI Supercharged option and re-prop it with a $1,500- 5 blade mercury stainless prop. Just remember to raise the anchor before you take off.

[dfox]

Generally speaking 2-50hp against 1-100hp the single engine will beat the twins speed wise. Torque maybe greater on the twins but the extra drag of two gearboxes will limit the speed obtained for equal horsepower. Theres alot of variables involved...foxy

[Tidas]

I agree with dfox, I think you'd find the single 100hp quicker. Don't forget the twin motor setup will be a lot heavier, would probably use more fuel, and you'd be up for almost twice the price every service.

There is more security with two motors in the event of a breakdown but the manouverability advantage is pretty limited on a smaller style boats where the motors are so close together.

Cheers,

Paul.

[revs57]

G'day Korey,

I understand the arguement goes something like this...

Two engines will get up quicker because of more lift in the bum with 2 props, but becuase of the two leg and props it becomes a disadvantage when your motoring.

Also you lose a little efficiency with two engines becuase of that fact and reduce overall performance about 20%. That means 2X50hp have the power of approx an 80hp

Two engines mean you have more trim control and wont need trim tabs if that is a factor and as Titus mentioned theres the obvious safety aspect maintenence factor and fuel usage

But it is a question worth considering depending on your purpose...I seriously considered a twin set up for our new 6mt...90's or 115's, but opted for a single simply because the right motor came along that was very affordable

cheers

Rhys

[billfisher]

If the boat is not too big (ie under 6m) your could consider getting a smaller auxillary motor. This way you get a back up engine but avoid the disadvantages of twin engines.

[Duyz72]

You could just as easily theorise that 100 x 1HP engines???

I have always been taught that it is the HP rated at the where the point of motion or force is applied (ie prop on a boat, wheels on a car) so 50HP is still only 50 HP and having 2 of them does not equate to 100HP.

[korey88]

thanks people thik ill opt for a single