Mercury Racing 525hp start up, nice sound ! 

Awesome!

Good explanation..........be fun to run a big water tank in the trunk of a car with the same set-up and go tearing down the blvd balls-to-the-wall shooti'n out a Rooster Tail.......sort of....!!!!!!

Well, it is a V8 Mercruiser...kind of

Nic Derkez Thank you so much for your nice comment!!

Your very welcome, you guys deserve it!

Oem Mercury Racing headers

It’s an oem set up. It was just to fire them up for the customer who bought them from somewhere else. Bad conditions, garden hose for cooling and small gas hose. Hence the lean running (high idle and a bit of misfire when reved)

Erwan Rivoalen Erwan, tu les as finalement montés dans ton Cigarette? Cool man 👍

No you’re not! 😂

@@MattFreedom75 That's reassuring ;)

There’s a flywheel tho

@@MattFreedom75 would have been hard to start without one lol, don’t see too many mercs like that here in oz,plenty of v8’s but mostly ford and chev

@@needmoreboost6369this is a 525ci bbc.. atleast the Guts are. It has coil packs and fuel injection but it’s a bbc.

​@michaelratcliff4440 it's a 454 big block Chevy. Not 525 cubic inches it's actually called a 525 because of horsepower rating. Working on a 47 foot fountain with three of these bad boys right now! They do sound mean!

To cool the exhaust cause boat engines are working in enclosed compartments

The water is from A water source to keep the whole engine cool. It picks the water up thru the hull. Water is pumped thru the engine and any other water to water cooling exchangers. And exits thru the exhaust in some cases. Other applications water exits its job to cool engine thru hull fittings.

@@michaeljeppi1584 Actually in this particular case, water is only used to cool the heat exchanger (engine is closed cooled, like a car) and the exhaust

I dunno much about how engines are run in a boat. But i'm pretty sure that's water and not fuel. If that was fuel, given how well the engine runs on it, it'd have to be a super rich nitrometh mixture. And i doubt that.

@Gabe Lackman lol

part of the water cooling system.

Not very smart are you about marine engines🤔🤔

525 not 502, the 502 is 8.1, these are 8.2 (mines by the way ... well it was ;)

c'était sur le mien: cigarette 35 awesome de 1977, il avait donc un jumeau :)

It’s a Boat Motor Numb Nutz

Up to 1750 hp actually

@Dylan East and it dampens (literally) the noise as well

@Dylan East makes sense. I thought it was raw fuel lol. Just shows how little I know of marine engines hah

not chrome , polished

Boat motor high rpm

Yes it does, not running right, really small gas hose is maybe the cause. It was just fired up to satisfy the customer who bought it somewhere else.

Because water is only injected into exhaust where it bends downward, headers are water jacketed. To avoid hydrolocking in case of engine failure, sudden deceleration, a wave with engine stopped and or bad captain, a rubber flap is usually mounted on the exhaust tips or somewhere in the exhaust line.

@@MattFreedom75 Are those two black pieces of rubber hose connecting the collector end of the headers to the stubby exhaust pipes carrying water from the water jacket to where it's dumped?

@@jtqthetieman Yes exactly 👍

@@MattFreedom75 Bingo! I understand this, now. I have to wonder if this swept up header design makes it a pain to do anything spark plug or valve cover related.

@@jtqthetieman Everything on a boat engine is a pain to do when it’s sitting in the bilge😉. But no it doesn’t make it more difficult

Not sure🤔...but a shit load of smiles for sure! 😁

for reaching higher Rpm I think, they use this technique in model RC cars in the past.

Those headers are water jacketed to allow them to cool while inside a closed engine compartment. It's the water transfer hose.

Could be heat exchanger to pre heat incoming cooling water before it enters the block..

@@rebekahfrench5747 correct. Also cools the headers at the same time

It’s a water hose. The headers are doubled walled and water is injected between the walls , this is the place that the water coming from the headers is injected and mixed with exhaust gases

It wouldn’t idle. It had some kind of problem. Wasn’t running really good also. The customer who bought them just wanted to know if they start.

There were actually two of those engines

I'm glad you mentioned this......I was going to ask the same.......I think the engine coolant return is passed thru the exhaust & tied into each header primary thru I think that silver pipe under each primary. These off-shore race-boats must use freshwater cooling system with no radiator..... I think..... NEVER MIND. See comment by Pappa Cheeze 1 day ago: "For every one wondering, the extra liquids coming out of the headers is water, these engines aren't cooled like a regular engine. in this case the water is pumped into a heat exchanger that cools the antifreeze. After there is no need for the water so outlets are hooked up to the bottom of special headers and is pushed out by the exhaust and more water still coming. (the headers have ports so it isn't coming back into the cylinders)"

Scroll down the comments, you’ll find your answer 😉

That was a small wooden hull.

😂🤣

It is. Damn man that's nice!

mounted with its twin in a 1977 Cigarette 35 Awesome 😎

🤣

Jesse Anderson emissions? On a boat? Never seen it in my life

@@cameronnalley3197 🙄

Jesse Anderson what

lol stick to what you know

lord kingshit lmfao

To my calculations and measurings yes. But you will need a water tank and a big nest (S2000)

if u have a Honda u dont deserve real muscle

Nothing I am aware of

Sorry didn't see you comment. Corsa performance makes silent choice exhaust diverters that fit your boat. You can also run a pipe between the manifold and exhaust tip but install a flap on exhaust tip so no water can run up the exhaust in case of bad handling or engine failure

Thank you 🙏

Scadieee Yes, there is actually two ways to cool a marine engine. External pump to send sea water to the engine and headers with a circulating pump to circulate water thru the engine. or External pump sends sea water to headers and heat exchanger and circulating pump circulate engine coolant thru the engine. This system is used to minimize corrosion as sea water only circulates thru the headers and heat exchanger.

Oh wow that's amazing to know, thank you

You're welcome

in addition to what smell of gasoline said, here was something i couldnt wrap my head around until i broke down a mercruiser exhaust and studied it. youll notice towards the end of the video that they actually touch the exhaust pipes and hold their hands on it for a second. with a normal automotive engine, if you did this, someone else would be opening your ketchup bottles for a long time. however on a marine engine, the exhaust pipe is a pipe within a pipe. the header has a larger diameter pipe over it with a gap between the two and cooling water is circulated thru the gap to cool the headers. after the cooling water passes thru the headers, it exits and goes to the exhaust tip. if you notice the black horse shoe type hose at the top of the headers, this is where the cooling water exits the headers and mixes with the actual exhaust to cool the exhaust gasses as they exit the boat. all this is done to keep the engine and exhaust cool because typically marine engines are closed in a compartment and cant get any cooling air to cool them, and as well you dont want the engine compartment of the boat to get too hot. hope this helps explain things.

Matthew Saia Thanks, sure did

Essentially the cooling system. This is a 500 cubic inch engine, it is not very powerfull compared to the displacement. You have to keep in mind that a boat engine constantly pushes the boat, it is like a car going only uphill.

O ok

boat engines are more about torque than horsepower along with the cooling system being different as was stated before the camshaft profiles are totally different than say a street drag or circle track cam and like smell of gasoline said it is constantly pushing against the friction of the water

I don't know, first start in years of an unknown engine. I was working for another company at the time and just happened to be there.

@@MattFreedom75 Sounds good to me.

Noise is part of the thrill 😉

@@MattFreedom75 süper

or may be coz the engine is cold...

@@marcelojaviertwt I think it is the water that cools the engine being expelled because it is a boat motor.

The Mercury Racing 525 EFI has two separate cooling systems. One is closed and used coolant like your car. The other uses raw sea or lake water, that’s what’s coming out of the headers

Indmar has a 6.2l ls3 based engine that you'll find in many sport towboats. I believe their manifolds are uscg approved

CMI?

Try TNT Marine in Miami; best of the best,,,,,,,😎!!!

Thanks

Thank you :-)

You know how your car gets cooled by a radiator by the wind. Boat motors get water cooled. They grab water from out of the water and runs it through the motor. I think in this setup on this 525 it’s a water cooled radiator. If you have more questions I can explain it a little better to you.

Those boat engines are watercooled. So after it goes through the engine it exits out the exhaust.

​@@crazymariofan8806 fascinating

@@HarryDaRat yea

😂

Albert Smith it’s a boat engine

Bro?!

Jesse Anderson bro?!

Albert Smith you see that thin chrome piping at the base of the headers? That’s the plumbing that expels the water that was used to cool the engine. The water just exits the headers instead of recirculating through the engine.

@@Maxumized fantastic explanation,thanks man.👍🏽🙂

It’s cooling water coming out of the exhausts. The engine itself runs too lean

I know.....

@mercuryracing

CP Performance...They're CMI Headers

@@bigmeaney555 thank you sir I appreciate it

Seems like they where over $7k

@@ronyoung6054 No problem

You're right, this engine needs some tuning. It was stored for a long time and fired up the first time on this vid.

Это лодочный двигатель. Охлаждение проточное без замкнутого цикла.

better out through the transom than in the bilge. Once you touch your bikini ass to hot headers, you'll REALLY appreciate the water-cooled ones.

All marine engines run water for cooling purposes

water. those are wet headers.

@@sparkyguitar0058 water ? R u kidding me? This for car or boat ? Bcs i see some vid more tu boat .. Idk bcs i just know a basic engine

@@teewoods9846 water ? This engine for boat or car ? Bcs i saw some vid this Marine brand more to boat racing ... That why i ask uolls .. I just know a bacis engine like turbo , vtech other else ...

Btw thanks for reply me my question thankss 🙏

Water injection into the exhaust system. Works as a muffler. Sort of.

Don't know if it's rich or poor but actually it was running a little rough. It was the first start in years

Is the cooling system once through? Is the cooling water injected into the exhaust to get it overboard?

@@clwomble In this case the engine is closed cooled, like a car. Water only runs through heat exchanger to cool coolant than through exhaust

Take what i say with a grain of salt.lol

🤣

Don't you see the water pouring out of the exhausts! 100% Mercury Racing original boat engine.

those are water injected headers.

You are dumpass... That is genuine mercury racing 525.

@@TheReinoPaasonenI speak English, French & Russian but not unfortunately your language (whatever it is). Further explanation required.. 👍

said no one, ever

It’s just different, not for the same use. Nowadays a Mercury Racing inboard can develop as much as 1750 hp so 3 times as much as the most powerful outboard. Nothing to do with present or past just not for the same use.

@@MattFreedom75 I've seen 4 300s on the back of a boat on a trailer going down the highway. Never saw it run, but pretty sure it was way out of my price range. If you have an older boat that needs a new motor (like my old SeaRay), that Mercury Racing setup might make the fish just jump right into the boat...two-legged kind, too. Probably need a beefed-up Bravo2 or X or something. Those water headers run cool to the touch, just shut the water off while the engine is still running or you could hydro lock the thing.. Used them on jet boats in the 70s.

@@stevenredman1582 😂 two legged kind....this particular set up had Imco drives

un**

????? It's WATER for the COOLING.......no fuel!!!

Fuel? That's water, genius.

Hader Mirza what? You believe that’s unburned fuel and they just let it run like that and it doesn’t start a fire? You must be special. I swear way too many people on this video don’t know anything about engines. Or how they’re cooled. 🙄

Hader, 1 size smaller main jets in the injectors should cure that.