exhaust question
 

Will running diverters for thru hull exhaust be quieter then just straight through hull exhaust? i was showing my boat to much uncle as well as looking up some videos online of boats with through hull exhaust and a 454 engine, i found this one: http://www.youtube.com/watch?v=qBu58Kvj7KM

and my dosnt sound like that mine is quieter, and also my uncle says it sounds quieter then his chevelle and his BBC with open headers.

If you have the diverters that dont have the switchable flappers inside(captains call, silent choice) and just direct some exhaust thru the prop and some thru the thru hulls, than yes, it will be quieter than straight thru hulls. I belive that setup is the corsa "quick and quiet" or something like that. I would buy the switchable ones, then have full quiet, or full loud setup.

yah i dont think it is a corsa setup, it came with the boat, it has flappers but it appears to only be, all quiet or some hull some prop

Does it have electrical wires going to the diverters or air tubes? Maybe the actuators are going bad or something.

no there are no motors or actuators on the diverters there is a place for them to be, but there are just levers there with nothing, but im pretty sure it is either split or only quiet not only thru hull, because of the positioning of the lever just dont see a way for them to do both

just went and took some pics hopefully make things easier

http://i138.photobucket.com/albums/q...9/100_2245.jpg

http://i138.photobucket.com/albums/q...9/100_2242.jpg

I just removed my Corsa Capt. Call system that was electrically switchable between all exhaust going under water or thru hull. It is louder going straight exhaust then it was going thru diverter system even when in thru hull mode.

thanks for the info TH that seems to be what im leaning towards. just looks like it will be a 12 inch peice of 4inch exhaust tube gotta see if we have any stainless laying around the shop think all we have is mild steel.

Have you tried moving the levers????

Looks like a switchable system that broke and someone just left the diverters and probably locked them in one spot.

it is defaintly a switchable system, however i think it is only switchable between Quiet and mixed ill try to take them off tommarow to get a better look at them, just need to see if i have the pipe at the shop

Years ago, I took some 5" diesel steel pipe and made a double 90 degree ell that I was needing in my boat. Then I got it hot dipped galvanized. It never failed. Also, those cast iron risers cost me a few motors when the gasket failed. Just my 2 cents.

how did they cost you a few motors? what did you do to change it?

You need to change teh gaskets between the manifold and riser at least every year or 2. If they fail, water will seep back into the engine. It will hydrolock and bend the rods.

The exhaust will take the path of least resistance---which is straight out the tips. Very little will go out the prop even if its mixed.

BTW, a stock 454 in a boat will be quite a bit quieter than open headers in a car. The boat exhaust is muffled with the water mixing with the exhaust.

The cast iron risers to manifold connection will get eat up with rust on the i.d. (I was in salt water use). Water can leak in to your engine and you can't see it. Merc. tried to resolve this by making a SS riser. However, the SS riser expanded differently than the cast iron and again the gaskets failed. My final resolution was to replace the cast iron manifolds with Stainless Marine units. No more issues.