500 bulldog
 

Did mercury ever make an engine called a bulldog or 500 bulldog that wasn't a 540 ?

Thanks in advance
Don

Not that I know of.

people often like to call their 500's ''bulldog''. I guess it sounds more powerfull with bulldog instead of 502's...

The made a 540 called a " Bulldog" and yes they were around 500 HP. They had a great short block which consisted of a GM Bowtie block, Carrillo H Beam Rods, JE Pistons, and a 4340 4.250 crank.

so if it's tagged bulldog...it is a 540?

Yes. Below are the specs:

Mercury HP 500 Bulldog Specifications

Propshaft Horsepower: 470/350
Full Throttle RPM Range: 4800-5200
Displacement (CID/CC): 540/8.9
Bore (inches/mm): 4.44/112.7
Stroke (in.)/(mm): 4.375/111.1
Compression Ratio: 8.6:1
Cylinders: V-8
Fuel Requirements: 87 Posted Octane

BL

Correct, great motor. Rated at 500 hp, but were a stronger running motor than the HP 500's. The 540 cubes pulled a lot harder on the bottom end and mid range.

Hey big D you're making me curious as to why the question?

They were a great motor to supercharge.
You ordered a Bulldog with #3's and SC it...you were in the mix.

Tall or short deck?
 

Are Bull dog tall or short?
Thanks
Steve

They are a Tall Deck. ( 10.2 ) Just did a rebuild about 300 hrs ago on my set of Bulldogs. They are now 572 ci and 700 hp. The casting number on the block is 14044807. This is a Mark IV Bowtie Block with siamesed cylinder walls and reinforced decks. GM dis-continued them a few years back. These blocks are getting very hard to find.

My dad is having his redone and I was suprised to see it did not have a roller cam. Is this right?

That is correct. They used a Hyd flat tappet cam on these motors. Most of them were from Crane with a .559" Intake and .578" Exhaust valve lift. Have his engine builder measure the cam lobes and see what numbers he gets. With the new oils out there without the zinc additive, you may be really surprised to how much wear there is on the lobes. Make sure he goes with a nice roller set-up on the rebuild. He can run more aggressive on the lift. Depending on which exhaust he is running, He may want to stay around the 112-114 center line on the cam. I am running a 108 centerline on mine, but also semi dry exhaust. and even with 25" dry/wet tailpipes, I still worry about reversion at a idle. With alittle work, you should be able to get 600+ hp out of these motors easy. They were built with all the good internals and were built to run. Take a look at the back casting "# on the block. It should be a 14044807. This will let you know that it is a Mark IV Bowtie block that they used on the Bulldog. Like the other post stated, There are alot of people out there that want to say that they have the Bulldog package, but are really just HP 500 ( 502 ). Good luck with your build.. :)

Correct

Even send RM Builder a message as far as some upgrades and a cam for your dads motor. This man is a wealth of knowledge and I know alot of people that are very happy with his work. He will steer you in the right direction.:)

Thanks. He blew a head gasket so he only did the one motor, basic refresh. They did have to have JE make another set of pistons as 2 were damaged. Apparently they are not a shelf/production piston They did change the cam, same spec. It should be done tomorrow. Yeah the builder ran the casting # and told him it was an '88 block, In a '98 boat, we were worried of a fraud at first.

What heads did they come with?

X2??

GM Rect ports, same as the regular HP500.

GM OEM
990/088 rect port. The cylinder head was the weak link in these engines.

Bob