Fimbultyr

Hi. Heard that a 496 mag ho needs open exhaust or silent choice due to the high power or you can burn your valves and the engine can run hot.
is this true?
i got a 496 mag ho in our cruiser and thought about remove the silent system.

PA.WOODCHUCK

Interesting claim...

DiamondPerformance

iTrader: (2)

Mercury says to never run your silent choice, closed, over 2600 rpm.

BUP

iTrader: (9)

It requires the open sleeve at the transom exhaust flange. Make sure you do not have the full exhaust bellows that routes the exhaust thru the prop.

Fimbultyr

i have the "open" one so it will work?

its in my cruiser and use to be att 3200rpm most of the time. Never wot runs

BUP

iTrader: (9)

cruiser boats route exhaust different ways and so forth but It sounds like you have a bravo 3 ?? twin engine boat ? if so then you will have the standard Y pipe and then thru the transom and out the open end sleeve ? Anyways put some pics up if needed or explain exactly what you have for exhaust and the set up / routing

Fimbultyr

im sorry
its a single engine boat with a bravo 3.
for now i have a silentchoice from mercury
and a standard y pipe through the transom and to the open sleeve.
And i want to remove the silentsystem and replace it with 4" "elbows" down to the y pipe.
And just wondered if this may couse trouble due to high resistance to the exhaustflow
couse i heard that the ho models need open exhaust at higher rpms