hp 500 horse power

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02-11-2015, 05:32 AM

#21

242LS

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Quote:

Originally Posted by bigboat28

No problem Deep lol

Now back to my question. Is that earlier post of 550-570hp gain with a cam change correct or can i get closer to 600 or more? I am just a poor fireman trying to make my old boat go faster, haha.

My "Bob cam" paired w/AFR305 heads from Marine Kinetics yielded 604HP on the dyno.

02-11-2015, 08:18 AM

#22

stimleck

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Quote:

Originally Posted by 242LS

My "Bob cam" paired w/AFR305 heads from Marine Kinetics yielded 604HP on the dyno.

was this based on an HP 500?,
Would I be correct in saying that the difference between a 502 mag and an HP500 is the heads and cam and therefore AFR 305 heads and a BM cam would produce the same power on a 502 mag?

thanks

02-11-2015, 08:20 AM

#23

stimleck

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wouldnt it be better to purchase new assembled afr 305's rather than buy oval ports then have all the work done?
The price difference would be pretty close but you would have all new?

Just curious as this is part of my plan for next year

02-11-2015, 08:32 AM

#24

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Quote:

Originally Posted by phragle

didn't innovation/volvo make a 600 hp 502 with the standard heads and holly fi?

Copy and pasted:

Quote:

Introduced in 2000, the DPX 600 and DPX 500 engines are the high-performance flagships of Volvo Penta’s gasoline-powered stern-drive line. Both are based on cast-iron blocks from General Motors. The 540-cubic-inch DPX 600 develops 560 horsepower at the propshaft, while the 502-cubic-inch DPX 500 develops 475 horsepower at the propshaft.

02-11-2015, 10:03 AM

#25

Full Force

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Quote:

Originally Posted by stimleck

I was just stating a combo that made real decent power in simple build

02-11-2015, 11:06 AM

#26

242LS

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Quote:

Originally Posted by stimleck

HP500s. No idea about 50 mag.

02-11-2015, 12:17 PM

#27

phragle

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correct me if Imm wrong, very well may be... but didnt merc use the same heads on the 454/502 mags, the 420, the 525sc , hp500 and lord only knows what else....

02-11-2015, 12:31 PM

#28

MILD THUNDER

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Quote:

Originally Posted by phragle

correct me if Imm wrong, very well may be... but didnt merc use the same heads on the 454/502 mags, the 420, the 525sc , hp500 and lord only knows what else....

YES SIR. I believe the HP engines may have got 2.25 intake valves and a performance valve job. Generally speaking, there isn't anything exotic in the engines you mentioned from a crank, piston, rod, etc standpoint.

Many have upgraded cams in stock low compression merc engines with good results over the years.