engine question

[paddymac03]

Hello, I'm looking to power a ZODIAC PRO 20 with twin honda 150's does anyone have an accurate GPH rate for this combo? Thank you

[9D280]

Paddy,

Welcome to ribnet!

I can be absolutely no use here with a direct answer, but there have been numerous fuel consumption threads in the past. Have a search through the forum (the search engine is pretty good) ansd see what drops out.

As you are presumably thinking of going twin, be aware of the "perennial discussion" surrounding twin engines & economy..... There are some fairly strong views on the matter!

Having said all that, "accurate" fuel economy is a bit of a difficult one for boats - for example if you motored upriver all day, you would be drinking more per mile than going downriver with the "road" pushing you along too. Weight & it;s distribution, engine trim, hull shape & driving style are also big influences on fuel consumption. A good rule of thumb seems to be about 1L/ nautical mile as a going in point, regardless whether you have a 3L V8 on a 26' hull or a 2 cyl 25Hp on a 16' ......

[willk]

I've missed something somewhere. Do outboards not return a fixed GPH at a fixed rev?

How fast the boat goes is another matter obviously...

[9D280]

Engine load will affect it.

Hence my comments on trim / balanc / weight distribution......

Somewhere on the net were some tests , although from memory they were Mercs...

[paddymac03]

to 9D280
Thank you very much for the reply and very sorry took so long to get back to you.
I'm aware of all of the above was just trying to find something to give the bank and the accountant (the "numbers" people they are) Thanks again. BTW love this site!

[clydeoutboards]

From a test of 150 hp outboards in a swedish boat magazine:

Boat used: Flipper 605 WA (6,15 meter x 2,32 meter, total weight at test 1400 kilogram, water temp 18 deg. Celsius

Honda BF150
Top RPM in test: 6000
Prop used: Honda HR, 3 blade, 20 inch pitch


b) Fuel consumtion (litre per nautical miles):
At max rpm: 1,27
Minus 500 rpm: 1,03
Minus 1000 rpm: 0,91
Minus 1500 rpm: 0,80
Minus 2000 rpm: 0,75


I know this is not your boat and its a single engine but sorry its the best I have.

Dave

[paddymac03]

Thank you very much Dave.

[Dirk Diggler]

Originally Posted by willk

I've missed something somewhere. Do outboards not return a fixed GPH at a fixed rev?

Nope

[willk]

Originally Posted by Dirk Diggler

Nope

I think you'll find that's "Yes" and "Nope" and

Originally Posted by 9D280

Engine load will affect it.

But thanks for the assist anyway

[Dirk Diggler]

Originally Posted by willk

I think you'll find that's "Yes" and "Nope" and

But thanks for the assist anyway

Uh Uh, deffo a nope to the original question!

[willk]

Originally Posted by Dirk Diggler

Uh Uh

Well again, thanks. If I ever need a spare part I'll keep you in mind, you tend to be wordier then

[Dirk Diggler]

Originally Posted by willk

Well again, thanks. If I ever need a spare part I'll keep you in mind, you tend to be wordier then

No need for thanks It's a pleasure.