H.P. of an EFI500
 

Can anyone confirm that the horsepower of a 2000 EFI 500 is 470? This is for insurance purposes. I was under the impresion that they are 500 at the crank. Thanks.

500 efi
 

470

Yeah what wgg said

Looked in one of my 500EFI owner's manuals, (publication # 90-840175001 999, copyright 1999 Mercury Marine). Specifications, page 61: "propshaft horsepower --- 470 HP". In my Mercury Racing Service Manual, Number 6, "Mercruiser Hi-Performance GM 500 EFI Engine", publication # 90-840283, July 1999, its listed as 415 HP ... obviously thats a misprint.

470h/p at the prop-shaft,right?i was told it is 500at the crank,and when through the drive it is 470h/p.is this right?

Correct.

500HP at the crank
470HP at the prop

Niether manual even lists crankshaft HP. Just propshaft HP. I added the publication numbers in case his insurance company wanted to verify the 470 number.

Mercury Racing rates all they're motors at the prop Mercury Marine rates them at the flywheel...

If that's true. How come Merc first rated the 525efi @ 500 prop ho, and the later, when they introduced the 600 sci and later models, the 525 was rated @ 525 hp, and not specified if it was prop or crank hp. From what I can see, they changed it, after the 575sci went out. That was 550 @ prop. I talked to a merc dealer about this a little while ago, and he said it was on the flywheel for both merc racing and mecruiser these days.

Another reason, I think why merc racing would not rate prop hp, is that a 525 with a ssm 6 would have a different prop hp than a bravo setup. So it does make sense, so rate them at the crank. I have no confirmation on this, but it seems like a plausable idea.

The 500hp and efi is 470 on the prop. Other examples for past motors are
Bulldog @ 470 prop
525sc @ 490 prop
575sci @ 550 prop
600sc @ 550 prop
800sc @ 700 prop
900sc @ 850 prop (dry sump six)


Sorry for the hi-jack.

For all practical purposes , How would you look at it on a NADA value??
Nada has an option for an adder for additional horsepower
the option is 415 to 470 H/P or 471 to 500 h/p
what would be used for the 500efi?
Its good for insurance purposes i guess that Merc rates them at prop . But the rest of the world in every market rates it from the flywheel.

NADA is pretty worthless anyway, but I would use the 471-500hp.

Can't argue the point about the SSM 6, but the 525efi actually puts out around 550hp at the flywheel and they realistically couldn't have a engine putting out that kind of HP that close to a SCI engine..Not too many would go the extra $$ for the 600sci...The 525efi is rated at 500hp at prop most reads you'll find are based on Bravo drive or at least anything I've read.

And of course you'll never get a straight answer from Mercury regarding tech information.