Make a little fast boat

csdwarf

Seaman Apprentice
Joined
Mar 29, 2010
Messages
33
Alright, i have an 8 foot hydroplane boat

right now im running a 9.8hp mercury on it and it runs around 20mph if i had to guess.

Its an alright speed for crusing around but when the water gets nice and calm i wana just be able to rip..


Strength isnt a problem the stern and entire boat is beefed up plenty and could take more horsepower then i would ever want to put on..



what would a good horsepower be? how fast would it go with

15hp- how fast?

20- how fast

30- how fast



I always have liked to run engines a little big, because you dont need to use the full horsepower and you can run a big engine easy insted of screaming a little engine



The boat will support plenty of weight,

Me(130lbs) my freind(150ish) and a 9.8hp could stand on the back of the boat and it still was flaoting, so it will take plenty of weight,


basiccaly im asking how fast you tihnk it would go with different outbaords

it does about 20ish with a 9.8, does that mean it would do 40mph with a 20? or what
 

clarkbre

Petty Officer 2nd Class
Joined
Sep 3, 2008
Messages
176
Re: Make a little fast boat

it does about 20ish with a 9.8, does that mean it would do 40mph with a 20? or what

No, it's all in the prop though. It depends on the prop pitch,diameter, and how easy the boat cuts through the water.

I'd me more curious/concerned with what the actual rating on that boat is. Do they race them or is there a class with a specific engine rating?
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: Make a little fast boat

as above.......the speed of the boat is determined by several factors.

prop speed pitch bite are just some of the fators....weight and drag are the others.....

being a little hydroplane the weight on the back of the boat will be a factor.

the boat may float.....but you still need to keep the weight down.....being only 8 feet.....the chances of a fly over are very real......that is not a toy

find a motor with higher horsepower and less weight.
 
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