4.3 vs 5.7 vs 7.4 ???'s

[Stud man]

Ok newbie here ...
I am looking to buy our first boat and besides a million other questions I have one about motors.
My 2 main concerns are power and fuel. I would like to know I have enough HP for when I need it but would like to be able to save on fuel most of the time
We really just plan on putting around, hanging at the dock , swim, fish and possably pull a tube or skier. you know boating, not really trying to get any where in a hurry

The 3 boats in question are...

1990 Sea Ray 280DA with 2- 4.3 LX engines (6 cyl /205 hp) Forgot to ask about the outdrive but will assume they are Bravo 1's
1995 Sea Ray 270DA with a 7.4 and a Bravo 2 outdrive
1998 Four Winns 258 Vista with a 5.7 Volvo Penta MPI ( 280hp) and a Penta outdrive with duel SS prop
All have under 400 hrs and have been yard mantained and are in the same price range.
I have been told the 4.3 's are like 6-8 gph and the others in the 13-15 gph range, is this true?
Will the 4.3's be enough for a tube or skier? and "get out of the hole"

Now i know this ALL depends on a number of factors, ie, RPM's, weather, weight, sea condsion's (sp) but some kind of idea would be nice.

Being it's just about winter and many are looking to get rid of their boats = high inventory and lower prices.
I figured to maybe take advantage now instead of waitng for spring

ANY OTHER info you could provide about the Boats, ie models, motors, things to look out for ( without going to far off topic) known issues would be greatful.
Thanks all
Studman

Oh I will be looking at these boats this weekend and we will be boating / docking in Long Island Sound off the coast of CT come spring

 

[TilliamWe]

Re: 4.3 vs 5.7 vs 7.4 ???'s

...

1990 Sea Ray 280DA with 2- 4.3 LX engines (6 cyl /205 hp) Forgot to ask about the outdrive but will assume they are Bravo 1's
...

Don't assume that. They are probably Alpha Ones. And if not, they could be Bravo 2s, but more likely the Alphas. Least likely to be Bravo 1s.

4.3s sound funny when you work them hard. My dad's twin 4.3 in his Regal 2660 were NOT pleasant at all to listen to. They did fine on fuel however.

None of the boats you list are going to get good "mileage", no boat does. The Four Winns with the MPI 5.7 has the best chance to get the best mileage. The 7.4 and the 4.3s would end up being pretty similiar.

 

[tpenfield]

Re: 4.3 vs 5.7 vs 7.4 ???'s

I posted a response of on the boating ABC forum. IMHO nothing over powered in that list, sorry to say.

 

[ewenm]

Re: 4.3 vs 5.7 vs 7.4 ???'s

i have twin 4.3 efi,s in my 32 footer and they work well, cruise at 26 mph (gps) and 3700 rpm and get reasonable fuel economy.

i dont tow toys as 32 foot is a fairly big boat to be whipping around to pick someone up, i would think that even your quoted boats are

borderline for water sports, unless of course you have lots of room to maneuver

 

[stackz]

Re: 4.3 vs 5.7 vs 7.4 ???'s

wonder what the advertised hp rating is for the 7.4?

regardless, the twin 4.3 setup is advertised at a combined 410hp, which is more than the single 5.7.

also, if you have a problem with one engine at least you can limp home with the other. cant say that with a single engine setup. but at the same time, you've got twice the maintenance costs too.

 

[starsnstripers]

Re: 4.3 vs 5.7 vs 7.4 ???'s

Most likely Alphas, I's stick with the 4.3s in that 28'er Best on fuel for the choices and 200lbs lighter with plenty of oomph!

 

[HT32BSX115]

Re: 4.3 vs 5.7 vs 7.4 ???'s

wonder what the advertised hp rating is for the 7.4?

It'll be approx 300 propshaft HP.

 

[bnicov]

Re: 4.3 vs 5.7 vs 7.4 ???'s

The Four Winns with the 5.7 duo prop sounds the most appealing to me. It's the newest and has a great engine/drive combo.

 

[Stud man]

Re: 4.3 vs 5.7 vs 7.4 ???'s

Wow thanks everyone; now my head is spinning more than before!
I posted on 4 different forums and got all kinds of info, just what I was looking for.
The results of all the posts..
4.3?s 12 yes, 5 no
7.4 3 yes , 1 no
5.7 3 yes , 3 no
I know that I will ?feel? which is the right boat for me but any info is great
Options from those who have more experience and own the very boats that I am looking for.
I will be heading out this weekend to see like 5 different boats and will post my finding.
Any other input is always helpful
Thanks
Studman

 

[geneseo1911]

Re: 4.3 vs 5.7 vs 7.4 ???'s

Fuel economy in a boat has very much to do with length, weight, beam, operation (cruise speed, acceleration, trim), hull design, and application (towing tubes vs. cruising at half throttle).

It has very little to do with engine size and power. An 18' boat with a 4 cylinder will get the same (or worse!) MPG as the same boat with a V8, if driven the same way. What happens though is that the V8 will go much faster and be driven harder.

The best fuel mileage of your choices would probably be FW, as I assume it is a 25' compared to a 27' and a 28'. Also, I think the 25' would be a better fit for water sports.

 

[Lou C]

Re: 4.3 vs 5.7 vs 7.4 ???'s

I also replied in the thread on boatingabc.com...if you're docking it in LI Sound waters (salt) better think twice about an I/O power package....if your marina is a high fouling area, its going to be a constant battle for you to keep the drives clean, I started painting my Cobra with anti fouling paint because the boat yards never take the time to do it right. Even following Interlux's instructions to the letter, 3 coats Primocon (primer) and 2 coats Trilux (anti fouling paint) I still get growth (lots of barnacles and slime) and I got enough barnacles in the water intake that it started to run hot. I had to clean them out, in addition to all the other I/O maintenance, which in salt water you must do if you want it to last.

If I was buying a boat that size, for salt water storage, I for sure would be looking to get a boat with straight inboards, Vdrives or outboards. Otherwise you are letting yourself in for a LOT of maintenance, whether you pay for it or do it yourself. Inboards +closed cooling, or outboards....