You got me, Trout.
Could be the 500efi was the start of the "parts box" HP500's versus the bolt-on HP500's.

Of course, ALL engine blocks are "precision CNC machined" when new regardless of where they come from. And the Merc Rods with the logo machined in them haven't been around that long though.

And I'm getting out of here while I still have a clear mental image of Wasabe's clean box...

LMAO :D :D :D


How bout them 500 efi's!

PS Box is Empty

DANG! Gotta TELL her you're there ??!

Better use a magnifying glass, eh?

:eek:

Raylar,
you know that was sarcasm right?
I also use Mobil one and change it more than once a season:D





BTW The box posts were too funny guys:crazy:

GM Announcement to suppliers late 2003:

"The 496 cubic-inch Vortec HP3 8100 crate engine will deliver more than 525 horsepower and more than 560 lb-ft of torque "

There is a marinized crate engine available too but I don't have a part number, HP rating or cost figure. The above engine sounds like a nice machine and heavy on the torque too. Obviously the HO Merc offers is a lower output version of this. The 496 can do much more obviously for much less $ too! Is this the new C-6 doggie too?

http://www.pistonheads.com/news/defa...p?storyId=5764

it's an old article; suprises me the merc HO is what 425HP?

any further info appreciated.

Well, guys, not to burst any bubbles, but I have a 2001 hp500efi on the stand right now, and there's nothing but GM in there as far as the short block goes......... JE pistons, GM crank, 7/16" rods...... nothing you can't order right out of the GM performance parts catalog. The oil pump pickup is welded tho as somebody said on here.

not that GM doesn't know how to build a motor tho..:D

we knew that right?

Sorry. :D

Hey Scott
I knew you were joking, hell you and I can't afford that Amsoil stuff anyway!
Sandisk:
Thought I would bring you up to date the GM HP3 engines that were annouced to be available by GMC and GM High Performance have been pulled from the catalogs and are not available do to technical difficulties. The difficulty is rumored to be that GM High Performance could not get them to make 525HP so they cancelled the offering. Thats one of the reasons we have been developing so much lately to get the output of these motors up over the real 500HP plus level normally aspirated! The only things holding these engines back are the stock iron heads(great boat anchors) and the factory intake manifold. In a few months this summer a few 496's will be turning heads as they buzz past a few 500HP and 525HP powered boats! Would somebody please take care of Wasabes hot box!!
Raylar;) ;) ;) :D

I agree, alum heads done right, cam, beef up the air/fuel CFM and look out. If you mill the heads can you increase the compression ratio too? 500+ HP?

Darn tootin!

I feel partially validated...

Uuhhh, since all of the Marine GM Vortec HP3's put out well over 525hp, I think you're right,
"The difficulty is rumored..."

why do you all use GM crate motors? The money spent when completed is the same if not more than custom built with wonderful torque curves per application.and usually higher RPM.Start with Keith Black blocks GM spin off. Just a question.

This has been quite the interesting thread. I honestly feel most everyone who participated in this thread felt they were offering facts, and no one was intentionally trying to offer wrong information. But I do feel this shows that what is advertised in boating circles may not always be exactly what you get in reality.
Such as, I agree that Mercury Racing always gave the impression, if not actually claimed that the HP500 series motors were all hand built from carb to pan. Obviously it was. Just not by Mercury Racing, as they would have us believe. I remember when they used to advertise a 3 angle valve job on everything that went out painted blue. After seeing some of the HP500 valves, I question that too, as well as a lot of other stuff.
I hope there are no hard feelings following this thread as I respect everyone who weighed in with catalog and website info, factory info, exectutive and technician "word-of-mouth" info as well as actual/visual part verification.
Let's face it gentlemen, GM makes really good stuff, no matter how big or new it is. Mercury is really good at marinizing GMs' stuff. Mercury Racing has some beautiful blue paint and cool valve cover decals.

Agreed. More mis-information here than fact. About a 20/80 ratio.

I can remember seeing a "three angle valve job" on a billing sheet from a supposed "authority" who also has an Offshore rigging shop.... after less than 6 hrs of running, the engine blew up... I found out that it only had a "one angle" valve grind... and USED parts that had been billed out as "new".... so,... you have to wonder what is the truth from anyone in the engine business.... :confused: