How many HP does my 5.7 litre mercruiser comp. ski have?

[Gerome]

I am puzzled. I thought I knew the power of my 5.7 litre mercruiser
competition ski inboard engine, when I came across different
publications stating anything from 215 to 270HP.
The engine is (as far as I know) a 1998. It has a 2 bbl carburettor.
Can anybody help me?
Also what makes a ski engine a ski engine?

Cheers
Marc Gerome

[Russ Glindmeier]

Gerome wrote in message <398ddd9a.0108...@posting.google.com>...

You sure about that 2 bbl carb? Never seen a 5.7 with anything less than a
4 bbl. I'm guessing you're looking down the throttle body of a TBI
injection system. Two injectors at the top of the throttle body. Could
easily be confused for a 2 bbl carb, I suppose. If it is a throttle body
EFI system, HP should be in the 260-270 range. It it actually a 2 bbl carb,
HP is something less, but I have no idea how much less.

Russ

[Charlie]

EFI and carb are the determining factors.

I just repowered my Mercruiser 5.7 with a brand-new bobtail, right from
Merc.

The old one (also a 5.7 from Merc) had a 4 barrel carb and was rated at 260
HP (at the flywheel). The new one has a 2 barrel and is rated at 250 HP (at
the prop) - supposedly the exact same HP, just rated differently.

Neither had EFI, both had/have Thunderbolt Ignition.

I'm looking at last year's (Y2K) Mercruiser sales brochure. It shows the
5.7L as 250 HP and 5,7 EFI as 260 HP.

So the answer lies in those two items. If you can identify the carb/EFI, a
dealer can probably tell you what the HP is.

Charlie
M/V Wavelength

[Doug Meredith]

According to the 1998 Mercruiser catalog, the 5.7 2bbl ski boat engine
is rated at 260 propshaft horsepower. The I/O version is rated at 250
at the prop. The difference being that HP is lost through the I/O that
is not lost through the straight shaft inboard.

Doug

"Gerome" <mar...@usa.net> wrote in message
news:398ddd9a.0108...@posting.google.com...

[Keith Beckmann]

The 5.7L is the 2 barrel carbureted engine, and the 5.7LX is the 4 barrel
carbureted engine.

Most of the 5.7L's I've seen were rated at 210 HP, while the 5.7LX's were
rated at 250HP.

Take a look at:

http://www.mercurymarine.com

and select:

- Products & Services
- Mercury Mercruiser Sterdrives & Inboards
- Product Family
- Inboards
- Small Block V-8

This is the current 5.7L, with a 2BBL carb, which is rated at 260 HP.

The original documentation for your engine will tell you what it's rated at,
but take that with a grain of salt. My 1996 5.7L is rated by the book at
210 HP, but the next model year, which had the same engine was rated at 250
HP. I think around 1995 or so manufacturers were required to list the HP at
the prop, where in the past they listed the actual engine HP

GM supplies the engines for Mercruiser. Check out:

http://www.gm.com/automotive/gmpowertrain/engines_marine/57_main.htm

This is the GM block for the 5.7L.

"Gerome" <mar...@usa.net> wrote in message
news:398ddd9a.0108...@posting.google.com...

[Gerome]

Thanks Keith,
great answer. It may really be the difference rating HPs that bring it
from 210HP to 250, unless they changed the engine significantly
between 96 and 98.
Marc Gerome

"Keith Beckmann" <Kbeckman...@wi.rr.com> wrote in message news:<0sOg7.143231$Jg.18...@typhoon.kc.rr.com>...

[punkin...@gmail.com]

There's no such thing as a stupid question, just stupid people that ask questions to.... online to stupid people that haven't been outside in 2 yrs and live in mom's basement searching to prove you wrong. Find/make a friend and ask someone you trust.

[punkin...@gmail.com]

It's 250hp to 280hp btw. Know the shit before you buy it dumbass, figure it out!

[Tim]

With the 2bbl, I don't know. The 305 4 bbl chevy in my 1977 23' Marquis is rated at 230.

BTW, idf their actually IS such a thing as a 'ski' engine, is probably the camshaft setting where you may have more torque at a lower rpm. That actually may be why the 2 bbl carb too. a two bbl carb has larger venturis than the front two of a 4 bbl. Which is only good at a wide open throttle (for the most part)

[waynebatr...@hotmail.com]

On Fri, 17 Mar 2017 17:24:00 -0700 (PDT), punkin...@gmail.com
wrote:

>It's 250hp to 280hp btw. Know the shit before you buy it dumbass, figure it out!

===

Most of the 5.7L Mercruisers of that era are rated at 260 hp.

[Tim]

Wayne Id say that'd be right for a 4 bbl model. Not sure of the 2 though

[waynebatr...@hotmail.com]

On Fri, 17 Mar 2017 21:38:11 -0700 (PDT), Tim <tsch...@gmail.com>
wrote:

===

You're right, probably a bit less. Mine was a 4 bbl as are most.

[Tim]

That is odd Wayne, I'd never known of a 2V carb on a 350 GM in a marine application till now...

[Bill]

My 5.7l fuel injection is rated 330HP. Never see that in the boat.

[Alex]

That post is 15 years old. Gerome might be pushing us daisies by now.

[Mr. Luddite]

I also am of the understanding that horsepower is measured differently
in marine applications as compared to how it's measured in a vehicle.

[gfre...@aol.com]

On Sun, 19 Mar 2017 07:41:36 -0400, "Mr. Luddite" <nowa...@jose.com>
wrote:

They used to let manufacturers use BHP (measured at the crank). Like
cars changed to being measured at the wheels (70s), it changed to
being measured at the prop in the late 80s.
At the time, the story was my 75 Yama/Merc put as much power to the
prop as the old Merc 100 "tower of power"