fuel burn

[scoflaw]

Not sure where to post this. Looking at 27 and 28' sundancers. Single 7.4, twin 5.0,s or twin 5.7,s. 8000 lb boat. Any ideas about fuel burn with these combo's. Or pros or cons. Thanks

 

[veritas honus]

Re: fuel burn

You'll get the best fuel economy out of twins. The 5.7 twins will obviously give you more power. The 5.0 twins will be enough power for that length boat. I'm assuming an 8.5' beam. 4.3L twins will also be enough power, and will be the most fuel efficient. They will also have the bonus of the smallest maintainance costs and less expensive replacment parts.

Depending upon how much you use the boat, will dictate whether or not the savings from fuel economy will outweigh the double maintainance costs. 1/2 the stress on each motor as opposed to a single motor will also greatly increase the life of the motors.

 

[jasperboy]

Re: fuel burn

My 7.4L Bravo 2 single on a 29'6 LOA and 9'6" beam (just a touch larger and heavier than the SeaRays) is about 15 GPH cruising. The RPM's and how you can trim it out make a big difference. I always figure I get about 1.5 mpg's on average. Can drop to about 1.2 at WOT. I imagine twins would net better economy, but then again twice as much to maintain and repair along with additional weight.

 

[JoLin]

Re: fuel burn

4.3L twins will also be enough power, and will be the most fuel efficient. They will also have the bonus of the smallest maintainance costs and less expensive replacment parts.

Except, believe it or not, manifolds and risers. They cost more than the SB V-8 parts. It's not just Volvo. I've heard the same from Merc owners, too. Surprised the heck out of me. Otherwise, I'm quite happy with my 4.3's.

The Dancers the OP is looking at apparently weigh about 600 lbs. more than my Vista. If that's the case, I think a single big block will be hard pressed. Twin 4.3's will be better, but I'd want to try it fully loaded.

I'd lean toward twin V-8's and in all honesty I've never been a big fan of the 5.0. IMO the 5.7 has essentially the same fuel consumption and significantly more power. HOWEVER, I would not pass up a boat I liked simply for that reason.

My .02