Choice of Engine

[BobS14127]

The boat I'm looking at is a Bayliner 265, the standard engine is a MerCruiser 5.7L Alpha I 250 hp.

It's my understanding from the Mercury Marine website that this is a carbed engine. Bayliner offers the 5.7 Bravo III 250 hp and the 5.0L MPI Bravo III 260hp as options.

I was under the mistaken assumption that carbed engines were replaced by fuel injection as they were for cars.

What issues has anyone has with a carbed engine? Rebuilding an automotive carb was a pain I'd rather not do again for a boat engine. Is MPI that much better to justify the $2,757 price increase? Seems like I get more horses and a smaller engine with the 5.0L Bravo III MPI. Correct?

Is the standard engine sufficient for this boat, approx weight with engine is 5800 lbs.?

The boat will be used for cruising and weekend trips.

Of the 3 choices, which is best and why?

Thanks in advance for your comments. If this is the wrong forum, I apologize.

Bob

 

[Dakota47]

Re: Choice of Engine

I like the 5.7 liter engine alot better. more torque.

 

[BobS14127]

Re: Choice of Engine

Dakota47,
which of the 5.7's? Alpha or Bravo? If the hp on the Alpha and Bravo is less than the 5.0L Bravo III why is torque better?

Thanks,
Bob

 

[45Auto]

Re: Choice of Engine

I would go with the largest, highest HP engine. You'll probably find that it will be faster and get better gas mileage. See the following two tests from Mercury, closest boats I found for a quick comparison:

22' Crownline with a 260 HP 5.0 MPI, Bravo 3:

http://northamerica.mercurymarine.c...ives/5.0MPIBravoThree_Crownline220EX_0604.pdf

24' Crownline with a 300 hp 5.7 mpi, Bravo 3:

http://northamerica.mercurymarine.com/_media/pdfs/bhb/sterndrives/350MAGMPI_Crownline230BR_0304.pdf

Note that the 5.7 in the bigger boat is faster AND gets better fuel mileage.

In my experience carbs on boats have more problems than carbs on cars, probably because of the winterizing when they sit unused for 6 or 7 months and seals and gaskets tend to dry out.

Many people run carbs and are perfectly fine for many years. But I personally prefer fuel injection on my cars, and even more so on my boats.

Dakota47,
which of the 5.7's? Alpha or Bravo? If the hp on the Alpha and Bravo is less than the 5.0L Bravo III why is torque better?

Don't have the 5.0 Bravo and 5.7 Alpha HP & torque curves handy, but it is possible that the only place the 5.0 has more torque is at max RPM, thus giving it more MAX HP. The 5.7 Alpha could have more torque, therefore more power, lower in the powerband where you will probably be spending most of your time. In other words the 5.7 Alpha could have a "flatter" torque curve, with more torque down low and a little less on top. As a general rule more displacement = more torque.

 

[MikDee]

Re: Choice of Engine

Both engines have the same crank, the same stroke, but the 5.7 has a bigger bore 4", then the 5.0 at 3.5", they are Chevy 350cu in, and 305 cu in respectively, so the 5.7 will have more torque then the 5.0. I prefer the 5.7 myself.

 

[oops!]

Re: Choice of Engine

the guys here have said it all, and they know more about marine engines than i.

i have heard that the bravo III is a fantastic drive

good luck
oops

 

[TilliamWe]

Re: Choice of Engine

If you intend to have more than 2 adult passengers and a lot of weekend gear, forget both these options and go right to the 350MAG MPI with the Bravo 3.
If you will have only light loads, either the 5.7L or the 5.0MPI will be fine. Is the fuel injection worth the price difference? No, not really, but it sure is nice to just turn a key and have it start. Of course that 5.7 should be a TKS (turn key starting), so in theory it'll start everytime too.
5.7s have more torque than a 5.0
According to gmpowertrain.com the base engines that they supply are rated this way:
5.0 253hp at 4800rpm 302lb-ft torque at 3800
5.7 292hp at 4800rpm 370lb-ft torque at 3200

You decide which is best.

 

[tntitans21399]

Re: Choice of Engine

I know talking to a couple of guys that have jet boats, that they all like carbs better because it gives of a better sound. If you hear them they all sound the same loudness and the fuel injection get quieter as they warm up and the fuel inj. adjust. They are still loud but not as loud. But they did say the fuel injection does give them better performance and better gas mileage. So if you can afford the upgrade go for it. That extra torque will help you when you take off, and when your cruising that extra horsepower will let you move the throttle up so your not using as much gas, while the smaller you will need to give if full throttle longer to get to your speed and stay at that speed.

 

[tashasdaddy]

Re: Choice of Engine

i have the 5.7 Volvo, at 4800lbs deckboat, go 5.7 bravo III, you will be glad later. that 265 is a lot of boat to push, and resale will be better. why buy something under powered, and then have trouble selling it later. you have 5800 lbs, dry, add fuel, goodies, 6-8 people your now trying to move 7000 lbs.

 

[sickwilly]

Re: Choice of Engine

My carb (different engine) diesels or runs on -- a fuel injected engine would not do that.

 

[QC]

Re: Choice of Engine

The 5.0 MPI and the Bravo 3 will be fine if you're OK cruising in the mid 20's. The Alpha will be harder to plane no matter which engine is in front of it. If you ever want to see 40 MPH go with the 300 MAG and she'll be able to cruise at 30. Nice boat BTW . . .

 

[180shabah]

Re: Choice of Engine

My carb (different engine) diesels or runs on -- a fuel injected engine would not do that.

Your engine shouldn't do it either, time for service.

 

[Solittle]

Re: Choice of Engine

I don't know the 265 but I would not go with less than the 5.7. Years back I had a 27 1/2' bayliner flybridge (trailerable) with the 5.7 & Volvo outdrive. It was a slug and would barely get up on a plane lightly loaded.