Merc HP500 cooling

[convincer253]

My boat has a Hp 500 carb. My question is does anyone know a way to run less water through the exhaust (to make it louder) but still have enough to cool the gill headers?

 

[Bondo]

Re: Merc HP500 cooling

(to make it louder)

Nope...

 

[JustJason]

Re: Merc HP500 cooling

what the heck is an HP500???

 

[Zackman]

Re: Merc HP500 cooling

HP500 is a BBC from Mercury Racing... rated around 500 Hp.​

I would think you need to keep things cool as possible not loud as possible.​

If you want it louder, maybe build diverts from the outside of the transom which directs the exhaust to the cabin area Because I'm pretty sure it's very loud just behind the boat.

Seriously though, you may want to ask your question over at www.offshoreonly.com, those guys eat that stuff up.​

 

[45Auto]

Re: Merc HP500 cooling

Drill and tap the water passages and install solid brass plugs. Drill a small hole in the brass plug to let a reduced amount of water into the headers. If the motor burns up, go up one drill size in the plug when you rebuild the motor. Repeat this process until the motor quits burning up or you run out of money.