mxz800

ok i have a 99 454 mag efi, the manifolds and risers are starting to look rough. replaced the riser gaskets last year, but looks like a leak may be starting again. manifolds are flakey and just dont look great. what would be the downfall to putting dry exhaust with a small racing muffler and just dumping the water on my outdrive?? it baffles me why we pay so much for exhaust just to run water through and ruin it?? could i build a dry header and add water at the end of the tail pipes?? i am sure the noise would not be an issue as it would be no louder than a street car with big exhaust. what am i missing here??

thanks Rob

convincor

That style exhaust is only used on open engine compartment boats. Obvious they need to be cooled because of the heat generated in the closed compartment, otherwise there would be a lot of parts melting, and burning.
The new CMI stainless headers look like a good deal, and reasonably priced.

Vinny P

When guys say they are running Dry Exhaust, it means that the water and exhaust gases don't mix. BUT, there is still water in the manifolds and pipes for cooling. The water exits the pipes via a bung welded to the end of the pipes, which is attached to a hose, that exits through the transom somewhere.

Raypanic

My custom marine dry pipes mix the water and the exhaust just before the end of the pipe. This way you dont have to plumb it out the rear. I think most are this way, I believe CMI does it the same on it's dry pipes.

Vinny P

Ray,
Then wouldn't that be considered wet. The exhaust and water are still mixing. True they mix further down the line, but they still mix. I have seen several boats with water exiting the transom thru fittings for complete dry systems.

puder

the exhaust must be jacketed all the way to the tips. YOu shodul be able to dump teh h20 seperate from the exhaust BUT you need jackest all the way to the end.

now teh big question is why??? I had a setup like that (my jackets didn't run far enough and it ran SUPER hot (I had glowing tailpipes at night) The biggest problem with it is taht it is just too damn loud. Gave me aheadache and i liek loud exhuasts.

if your run muffler you need tome water too keep them cool. I know what are considered "dry pipes" often dump like 90% ofteh water out a seperate dump and the remaingin 10% goes out of eth tailpipes at the very end to keep the mufflers cool.

trust me you need the mufflers otherwise you get a nasty headache and the finger from fellow boaters in no wake zones.

baja bailey

My friend just put dry exhaust on his 35 Fountain. The exhaust was from Stainless Marine. I think he said the tips were made by SM also, the tips were made where the water comes out the very end so no water mixes with exhaust. Sounds real good, but like Puder said, it is LOUD....