Rated Horse Power

[Thongpoon]

I see alot of posts for getting a bigger motor so my question is this What makes up the factors for determing engine size. Is it hull design transom design or strength or engine weight. Just what determines the rated HP. Thanks

 

[gsbodine]

Re: Rated Horse Power

yes.

 

[JB]

Re: Rated Horse Power

What Ol' Norse said, plus engine torque.

 

[TOHATSU GURU]

Re: Rated Horse Power

USCG suggested max hp is determined by a mathematical formula based on length, width and depth.

 

[Thongpoon]

Re: Rated Horse Power

so nobody has an any idea how it came about. I follows internet outoard but I have yet to see a definate answer. What is the formula. Maybe I should take the 115 off the lund and put it on the 14 mirroecraft

 

[DJ]

Re: Rated Horse Power

Here you go. Section 183.53 of the USCG rules and reg's. I found this by using the search button (on this forum) and using the key words: "horsepower formula".<br /><br /> http://www.uscgboating.org/regulations/boatbuilder/part1/reg33_183_4a.htm

 

[phatmanmike]

Re: Rated Horse Power

formula is...<br />2 x length(feet) x width at transom(feet) - 90<br />so for 18foot boat with 7 foot transom would be as follows<br />18*2=36<br />36*7=252<br />252-90=162<br />162 is max safe hp as per coast guard.<br />this is just a general idea, some boats can handle more, some can handle less.

 

[gsbodine]

Re: Rated Horse Power

Originally posted by phatmanmike:<br /> <br />this is just a general idea, some boats can handle more, some can handle less.

Mike's right here, and this is why there is no clear-cut answer. It depends on design (heck, and condition, for that matter) and common sense as well.