Powering Down to 20hp

[Liopleurodon]

Re: Powering Down to 20hp

Taking one look into the racing hull idea...

What about a catamaran? One optimized for 20hp, 700lb, and 20mph. Take the design of a higher end jon boat (with the angled instead of flat bow) and take away the middle 2ft? I'm thinking a 16ft long boat with a cross sectional area more akin to a smaller boat.

Or would the hulls need to be more of a deep vee and designed not to plane? I imagine the pontoons could get rather long and thin.

 

[smokeonthewater]

Re: Powering Down to 20hp

seriously???????

NOT gonna happen

 

[Liopleurodon]

Re: Powering Down to 20hp

Ok, backing off from top speed here. Forget about current.

Given:
1. A max horsepower of 10 in one scenario and 20 in another.
2. An intended passenger capacity of 4 adults in one scenario and 6 in another.

What type of hull would provide the most efficiency?
1. Standard round aluminum pontoon
2. Converted sailboat
3. Other
And what would be the ballpark for speed?

 

[PPCS]

Re: Powering Down to 20hp

What about a 16 foot Aluminium boat? My previous boat was a quicksilver 500SF with a mercury 20 2 stroke. Planes 5 people with light gear. With 2 people it will do 24mph op the GPS.
You can have some comfort added and just cruise. Yes it is a small boat for 5p max, but it will go with 20hp.

Picture of my previous boat:

Good luck!

 

[JimS123]

Re: Powering Down to 20hp

When I was a kid, all we had was a 3HP knucklebuster on Dad's boat and we all thought we had the world by the tail. When he upgraded to a 10 HP we KNEW we were in heaven. Also at that time our neighbor had a 25 HP Big Twin and we were envious.

In contrast, a friend of mine had a Formula with twin 350's. Not good enough. He traded for one with twin 454s.

Another neighbor (an old codger) bought a bowrider that could handle a 175 HP outboard. All he does is fish up and down the river. He put on a 20 HP Johnny. He's happy!

"Nobody" is ever satisfied. The rest of us are boatmen and we enjoy the river no matter what.

 

[southkogs]

Re: Powering Down to 20hp

Ok, backing off from top speed here. Forget about current.

Given:
1. A max horsepower of 10 in one scenario and 20 in another.
2. An intended passenger capacity of 4 adults in one scenario and 6 in another.

What type of hull would provide the most efficiency?
1. Standard round aluminum pontoon
2. Converted sailboat
3. Other
And what would be the ballpark for speed?

Small pontoon - 10 to 15 hp. - you won't go quickly on that setup, but you can take 6 people and a reasonable amount of gear.

 

[Liopleurodon]

Re: Powering Down to 20hp

Interesting - I had assumed that for the weight and horsepower, a displacement hull would be better than a planing hull, that was the direction I was going. If I went with a planing aluminum hull but failed to plane, would a vee hull or flat bottom likely be more efficient? Are we looking at a "sort of" planing effect here, where there's some lift but not enough for a full plane?