500hp Gurus !!!
 

I am buying a 2002 Gen6 500hp and wanted to know the (easiest) best way to get 500 to 550hp. Also what is it stock. Thanks in advance.

heads and a cam. it's EFI so resurch who has done this and go with an experienced builder. I have tried the external add on crap for the EFi and nothing reall works.

Or do what I did over the winter and Whipple it !

Is is EFI or carb..could be either one....if carb..you might consider a 250 blower setup, run about 4psi or so..you could also do some porting on the heads like Jeff suggested and prob gain nearly 50hp..not sure if I would touch the cam or not..those HP500's have great cams in them that work very good and no rev problems, but that is also a choice...btw..stock hp is 500 @ the crank and 470hp @ the prop

After thinking about it..I guess you could only have a efi...carb was made until 2000 and efi started in 1999...so maybe the head work would be a good choice...OR THE WHIPPLE!

Stock power for a HP500 is 470 hp.
Tyler Crockett redid rebuilt both of mine recently.. basically heads, cam, ignition.. dynoed out at 585 hp at 5600 rpm.

Bajapred is right, stock power is 500hp, not 470.

I didn't think Merc still built the carb version in 2002.

The quickest and easiest path to 550HP.... :D well take off the EFI system and intake and sit it on the shelf....then bolt on a single plane and 850 and spin the motor 5800....and yes, I am being serious....If you're going to SC, no need to stop at 550....go whipple or roots with carbs and put up 800+ reliably....:drink:

I didn't want to lose my efi, if he's anything like me, he won't either. What about just swaping out to Aluminum heads? That should be good for 40 hp.....no?

Carder,

What speeds are you seeing? What is your set-up?

I am told it is a 2002 but it has a carb, This motor is going in an Advantage Citation 22ft. It has gil exhaust right now.

Don't waste money on the exhaust, you won't get any more hp. Those Gil's flow great.

If it's a carb, you have alot of options open to you.

If I were you I would fine a good engine guy close to you, check him out (talk to his customers) and then ask him what he would recomend.

Port the heads, change to a little more cam, and 550HP will be no problem.

Is there a difference when porting the heads for a car or a boat application. What rpm should i spin this motor at.

Bravo 1's on Stelling boxes, 1.5 gears.
29p Quad IV's hit the rev limiter of 5600 at 87 mph... with about 2 inches of unused throttle.
I have a problem with the stbd. drive, currently, but when that is resolved Julie at Throttles-Up has sent me a set of CNC 29p 5 blades to try.

Tyler got around 100 hp from simply doing the new Dart heads and a port job. The cam and MSD were icing on the cake... The dyno showed the MSD alone added 12 more hp.

Are the boxes -2 raising the x-dim?

The boxes both set back the props as well as raise the X

Why is the 500hp 500horse and the 502mag is only 415. Whats the difference

Thanks Carder...I suspected as much with those speeds.

From what I've read and been told the exhaust ports need work on the Chevy heads.
5600rpm should get you 550+HP.

Intake, valve size, cam, exhaust...

Wow, I am suprised by the MSD. I always thougt that the merc ignition was pretty damn good. Interesting though.

You need to compare the Propshaft horsepower..ie, 502mag = 415psh & the HP500 = 470psh add 30hp to get the crankshaft horsepower for each engine..FYI, the 525sc is a blown 454 that made 490 psh... the HP600sc is blown 502 and made 550 psh..the 800sc is a blown 572 and made 700psh..the 1000 sc was a blown 542 with high compression 9:1 ! and made 950psh !!! yikes..all the other blown mercury engines had 7.5:1 compression....also, the 525sc had a single 1050 carb..the 600 & 800 both had dual 700 holleys & the 1000sc had twin 1050's! they all had 4800-5200 RPM range accept the 1000sc it just had "run me @ 6200rpm" stamped on it!

Well there are a couple of things...(A) your motor is not a true '2002' HP500 because Merc stopped building carbed HP500's in 99'. (B) If it has a 02' serial number, then someone has already scrapped the fuel injection. It would be helpful to know which motor you have because they had a cam for the carbed and a cam for the EFI which are quite different. Non the less, since you are already cabed you have a lot more options..some of which have already been mentioned....:drink: But the huge hang-up with the regular EFI stuff is the very restrictive intake manifold and from what I have been told its very hard to make them flow enough to support better heads, etc...can the intake be modded...sure...but its only money....:p :drink:

The motors were bought in 2002 but were carbed so they must have been left overs from 99 i guess. It looks like the heads and the cam are the way i will go, what heads should i go with or is it cheaper to just port the stockers. Also what cam will i need to go with. Thanks for all the info guys.

probably similar price if you just buy soem good aluminum heads and blot them on rather than remove disassemble, port, ressemble and install the stockers.

Just my 2 cents.

I think the 500hp's are around 517 horse? 470 ish at the prop?

If 550HP is your goal the stock heads should be fine with some bowl porting and a valve job.
For 600HP, it may be more cost effective to buy new heads.
RMBuilder is man to select a cam to maximize the power of your combo.