How'd Merc go from 210 to 250 hp on 5.7L?

[teamgomez]

G'day all-

Going to sea trial a 1997 210 hp 5.7L 24' Sea Ray tomorrow. Been staying away from the 210 hp model b/c I thought it would be 'underpowered'. The next year's model (1998) had a 5.7L as well but it is rated at 250hp. Has to be the same block so what did they do to bump the ponies to 250?

The 210 hp boat I'm driving tomorrow has all the 'stuff' on it I'm looking for and she's been well maintained and re-propped. I'm thinking I could put a 4 barrel carb on her (holly marine 600cfm) and maybe a new manifold to wake up the lower end on the torque curve.

Anybody know what merc did to the 5.7L to get the addn'l ponies? Thanks!

~John

 

[H2ONUT]

Carb vs. Fuel Injection

 

[STIHLBOLTS]

MPI - Multi Port Injection. My 5.0L MPI has 260 hp will the carbed verson only has 220. Makes for zero start failures and smooth sewing machine engine sound. :thumbsup: Oh and it uses less fuel too!! :grin: :grin:

 

[SeaRide]

Gomez,

By '98 GM began supplying Merc. with the VORTEC engines which included better breathing cylinder heads. So the '97 2V made 210 HP and the '98 2V made 250 HP. The 250 HP version also has a slightly higher WOT range. My '99 5.7 EFI (TBI) makes 260 HP. In addition Merc along with others are allowed to fudge the HP ratings a bit as well. I can also remember during this time frame that one of our local dealers was offering the 5.7 over the 5.0 LX (4V 205 HP) at a minimal up charge. Marketing, supply or carb reasons who knows why the dealers/Merc were able to do so.

 

[brian thomas]

Better cylinder heads and a roller lifter camshaft. Made a pretty good difference. Manufacturers are allowed to fudge their hp numbers by 10% either side of the real number. Means a 250hp engine can be listed as having hp ranging from 225 to 275. The 210 was likely a little under rated and the 250 a little over rated.