What's the Horsepower of my Merc?

[Have Fun Today]

1997 5.7LX Alpha 1 drive, what is (or was) the original factory specified horsepower on this engine...250, 280, or 300?

Thanks

 

[Don S]

Re: What's the Horsepower of my Merc?

235

 

[QC]

Re: What's the Horsepower of my Merc?

I believe the 1997 Was rated 230ish at the propshaft. Is your engine EFI? If so it is 250 bhp at the propshaft. I don't believe there was any 280 Mercruiser then (or now) and the 300 was (and is) the 350 Mag MPI.

Edit: sorry Don, posting on top of you. There ya go 235ish

 

[Don S]

Re: What's the Horsepower of my Merc?

Actually, that 235 hp rating came from the #17 service manual and didn't say LX, no listing for the 5.7LX.
But I did locate a 97 owners manual that lists the 5.7LX

 

[John_S]

Re: What's the Horsepower of my Merc?

My '97 Merc Operations manual and Merc Service Manual #17 indicate that the 5.7LX was 250HP at the prop. The online #17 seems to be back-level from my printed version, because it doesn't show the LX or 5.7L2brl. ie mine has more columns and some different data.

 

[Have Fun Today]

Re: What's the Horsepower of my Merc?

Is the difference between the 5.7L and 5.7LX mainly in the carb (2-barrel vs 4-barrel)?

 

[Don S]

Re: What's the Horsepower of my Merc?

Got me, I never sat down and compared all the parts between the two.

 

[John_S]

Re: What's the Horsepower of my Merc?

"Is the difference between the 5.7L and 5.7LX mainly in the carb (2-barrel vs 4-barrel)?"

I have spent some time reviewing that through the service manual and online parts look-up. The main difference is the intake and carb. The LX has a low-profile 4brl w/750cfm weber carb. The LX also has a different timing advance curve, and a wiring harness that supports a knock sensor.

 

[QC]

Re: What's the Horsepower of my Merc?

My research says the LX is Throttle Body EFI. I had a '95, same thing, and it did call itself an LX now that I think about it. If that is what you've got, mine was 100% trouble free until I sold her in '04. 250 bhp at propshaft

 

[John_S]

Re: What's the Horsepower of my Merc?

There was a ton of different 350 models in '97. They had standard head carbed (L, LX, MAG) and efi, and gen+ efi models. The EFI, MPI, GEN+, or Black Scorpion would have been part of the model name. The books are not right infront of me, but think any of the TBI models had the same propshaft hp of the equivelent 4brl offerings.

Of course you can add the slight differences for the particular Alpha, Bravo, and Black Hawk Drives, MIE, etc, etc. I wonder why it is confusing?