hp500b?

amh44 · Aug 20, 2016

dose anyone know anything about the merc racing hp500 bulldog 540 motors my new boat has one in it?

BDMar · Aug 22, 2016

What would you like to know?

jeepdog · Aug 22, 2016

They're fast the more money you spend the faster you go...

amh44 · Aug 26, 2016

how good of a motor are they mine is running about 700hp naturally aspirated

tkrrox · Aug 26, 2016

I'm not motor smart but I was under the impression when pushing for 700+ you better start thinking blower if you want reliability.

Gelcoater · Aug 26, 2016

The Bulldog was offered at the same time as the carb'd 500hp.
Both Bulldog and 500 were rated at 500hp at the crank and 470 at the prop.
The 500 was based on the Gen V block and the bulldog on the Tall Deck.(I'm not hip on my GM alphanumeric bs,they may be the same block??)

The 500 was 502 cid(4.47" bore x 4" stroke) while the bull dog was a 540 (4.44 bore x 4.375 stroke).

Both used Crane cams and valve train.Both had the same 2.25x1.88 valve sizes in the same open chamber GM iron heads.
The 500 was 8.75:1 comp the bulldog 8.6:1, both ran on 87 octane fuel.

The 500 ran a GM forged crank,GM rods and JE pistons with GM rings and a GM oil pump with a GM stamped steel pan.

The Bulldog ran a Lunati forged crank,Manley forged rods and Weisco forged Pistons with Speed Pro rings and a Melling Oil pump with a cast aluminum Mercruiser pan.
Both ran Gil/Merc cast aluminum exhaust.
Both ran Carter high performance belt driven fuel pumps.
Both ran Holley 800 cfm carbs,both ran Dart single plane intakes.
Both ran Merc Thunderbolt IV ignition w/rev limiter.

Both were offered with Bravo 1 drives,but the Bulldog was also offered in Bravo 3 and 5 drives and came with a modified Borg Warner Model 62 transmission.

28Eliminator · Aug 26, 2016

amh44 said:
how good of a motor are they mine is running about 700hp naturally aspirated

If it's making 700hp, it's not really a 500hp Bulldog. What else has been done to it?

BamBam · Aug 26, 2016

Gelcoater said:
The Bulldog was offered at the same time as the carb'd 500hp.
Both Bulldog and 500 were rated at 500hp at the crank and 470 at the prop.
The 500 was based on the Gen V block and the bulldog on the Tall Deck.(I'm not hip on my GM alphanumeric bs,they may be the same block??)

The 500 was 502 cid(4.47" bore x 4" stroke) while the bull dog was a 540 (4.44 bore x 4.375 stroke).

Both used Crane cams and valve train.Both had the same 2.25x1.88 valve sizes in the same open chamber GM iron heads.
The 500 was 8.75:1 comp the bulldog 8.6:1, both ran on 87 octane fuel.

The 500 ran a GM forged crank,GM rods and JE pistons with GM rings and a GM oil pump with a GM stamped steel pan.

The Bulldog ran a Lunati forged crank,Manley forged rods and Weisco forged Pistons with Speed Pro rings and a Melling Oil pump with a cast aluminum Mercruiser pan.
Both ran Gil/Merc cast aluminum exhaust.
Both ran Carter high performance belt driven fuel pumps.
Both ran Holley 800 cfm carbs,both ran Dart single plane intakes.
Both ran Merc Thunderbolt IV ignition w/rev limiter.

Both were offered with Bravo 1 drives,but the Bulldog was also offered in Bravo 3 and 5 drives and came with a modified Borg Warner Model 62 transmission.

I'm not sharp shooting, but I thought the 540's were 4.500" bore and 4.250" stroke. Guess the math works out either way though. I do know the Bulldog was a Tall Deck block.

Gelcoater · Aug 26, 2016

BamBam said:
I'm not sharp shooting, but I thought the 540's were 4.500" bore and 4.250" stroke. Guess the math works out either way though. I do know the Bulldog was a Tall Deck block.

According to my Mercury High Performance Series brochure circa that era,my numbers are correct.

JBS · Aug 26, 2016

28Eliminator said:
If it's making 700hp, it's not really a 500hp Bulldog. What else has been done to it?

Listed on Craigslist [emoji3]

bocco · Aug 29, 2016

A little info here:

http://brucebullockmarine.com/mercury/500.html

amh44 · Jul 19, 2017

sorry guys been out for a while dealing with health problems but it is a hp500b been rebuilt with new high compression pistons bored .10 over loaded afr heads new cam and a few other things the 700hp is at the prop and the boat dose 98mph

bocco · Nov 29, 2017

Just read the oil viscosity thread. Mention of valve train maintenance reminded me of this thread. Everything I've read says that the 500hp is a gen 5 but mine has a cast timing chain cover which leads me to believe it's a gen 6. It's a 1997 also.The only service manual I could find is for the gen 5 version.

Anybody have any insight?

BDMar · Nov 29, 2017

bocco said:
Just read the oil viscosity thread. Mention of valve train maintenance reminded me of this thread. Everything I've read says that the 500hp is a gen 5 but mine has a cast timing chain cover which leads me to believe it's a gen 6. It's a 1997 also.The only service manual I could find is for the gen 5 version.

Anybody have any insight?

Easiest way to tell is the Gen V timing cover has same bolt pattern as the Mark IV, a stamped steel cover, and 10 bolts. Gen VI is a cast cover and 6 bolts.

hp500b?

amh44

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BDMar

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jeepdog

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amh44

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tkrrox

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Gelcoater

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28Eliminator

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BamBam

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Gelcoater

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amh44

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BDMar

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