Gas milage, 2x454 vs 2x540
 

I usually figure any big block will get 2 mpg cruise and 1 mpg WOT.
So I'm considering a 26 Seebold Eagle w 2x454 and a 38 Scarab w 2x 540.

I'm figuring the Scarab a 9000# boat w 540s is going to burn a hella lot more fuel then the 26' pad V w 454s.
Any ideas or comments?
Thanks
Evan

Re: Gas milage, 2x454 vs 2x540
 

The gas mileage factor was "nonexistant" until recently----now that gas prices are redicluous :mad:

Re: Gas milage, 2x454 vs 2x540
 

It would be more (the 540) but its all relative to the force applied to the right hand .... :cool: ..... 454 carbs or MPI ? my 454 mags ..averaged about 12-15 GPH ... that's overall ... idle time ...cruise ...some WOT ...9000lb 311 ... they are out now being upgraded to 509's ...will be interesting to see the difference ......m

Re: Gas milage, 2x454 vs 2x540
 

Gasoline consumption is related to horsepower.A certain amount of power requires a certain amount of fuel to make that power.A 454 making 500 hp at WOT for an hour will use 220 lbs of gas/7 =31 gallons of gas.
A 540 making 600 hp at WOT for an hour will use 280 lbs of gas/7 =40 gallons of gas.In some cases like a 525 Merc that has a very rich tune-up could burn more fuel than a 600 or even a 700 hp engine

Re: Gas milage, 2x454 vs 2x540
 

yea ???? well whata you know ???? :drink:

Scary ......... les see ....80gal x 3.23 = 258.00 ....crap!

so any motor not jetted right is costing $$$ ....

Re: Gas milage, 2x454 vs 2x540
 

You got that right ;) :drink:

Re: Gas milage, 2x454 vs 2x540
 

Go to www.boattest.com and find your boat, or as close as you can come. From what a have found, 454s best, is at 2700-2800 rpm's and with twins it's like 1.75 mpg. :(

Re: Gas milage, 2x454 vs 2x540
 

If you are interested in a 26' boat, why not look a something with twin small blocks?

Re: Gas milage, 2x454 vs 2x540
 

I'm not questioning your numbers but I have heard that it takes approx 1 gallon/hour to make 10 HP, so a 500 horse motor would be 50 GPH at full throttle. Maybe this is only true for the over rich factory motors?
I know that this is fairly correct on 2 strokes, as 300X's burn 32 GPH at full throttle.

Also would it be true that if you had a 500Hp 454 and a 500 Hp 540 both tuned correctly that they would both consume the same amount of fuel at WOT?

Re: Gas milage, 2x454 vs 2x540
 

I was kind of wondering the reason for twin big blocks in a 26 footer myself.