chris-jack

I am despaired! Which upgrades make sense with a silent exhaust?

Also if i really liked it, i cannot use dry exhaust. Exhaust systems over the water are not very common here, so i will have to use a muffler or silent exhaust.

But this make cam upgrades impossible and not getting a revision problem.

Any idea how to get out off this? I will have to leave the stock engine unmodified!

MILD THUNDER

You can still upgrade cams and run a setup like dana marine, stainless marine, imco, whatever. You will just have to select a cam that wont cause reversion. You should be able to go with a cam with up to about 230* of duration, on a 114* centerline with one of those systems. Which would be a nice upgrade from the stock 365HP stick.

With the dry setup, you can always run mufflers, or turn downs. My boat has headers, and dry pipes with stingers and switchable mufflers. The water doesnt enter the exhaust stream untill right before the mufflers. So as for loudness, its not much louder than a standard wet exhaust at idle. With the mufflers closed, its really quiet. You have plenty of options!

chris-jack

How is a dry exhaust cooled? With salt water or by cooling water?

DareDevil

With Saltwater in your case ,,,,,,or fresh water,,,,,if u run on a lake.

The same water that cools your cooler for the closed cooling system,,,,,you should have the same set up now then u need on these too, since your exhaust is cooled aswell .

chris-jack

Excuse me for my silly questions, but slowly i understand. The only difference of dry is that there is no mixture of gas and water.

I was first a little confused, because i sometimes have about headers which are definitly NOT cooled, they only could be used in open engine compartments and thats not what i wanted.

Thanks again for your kind support of my questions.

MILD THUNDER

Boat Headers are still like car headers, except they are water jacketed. Lake/sea water gets pumped thru them and comes out the end of the tailpipes.

You are correct about dry pipes, the exhaust gas and water do not mix, which allows for big wild cams. Stock manifolds dump water into the exhaust gas stream close to the engine, pretty much where the rubber hose clamps to the pipe on the riser. Aftermarket manifolds like stainless marine, gil, dana, etc, just dump it a little further back, which still helps for somewhat agressive cams. You do not necessarily need headers for dry exhaust, stainless marine, gil, etc, make dry tails for their manifolds too.

Griff

All boat exhaust is basically a pipe within another pipe. The same water used to cool the engines or heat exchangers passes between the 2 pipes and cools the exhaust.

Wet exhaust dumps water into the exhaust gas somewhere in the riser. In performance exhaust, it dumps it closer to the end of the pipes, right before the transom. Dry exhaust dumps water out a separate water dump in most cases and the tail pipes/risers extend all the way through the transom. Mine is dry, but dumps at the very end of the tailpipes on the outside of the transom. It looks like a wet system while running, but its actually considered dry.

KAAMA

For the most part ALL exhaust systems of an Inboard or Inboard/Outboard engine (by some sort of maritime law) must be water cooled to some extent to prevent your boat from burning down.

These must consist as some sort of double walled or jacketed type of exhaust system---whether it is a manifold or a tubular exhaust system although some exhaust systems set-ups dump water in directly into exhaust gas stream at or near the "riser" or where the "tailpipe" is connected at the "collector"---this is usually known as a "wet" exhaust system and can cause "reversion" if you have a cam with too much duration, etc. Most of the time a "wet" exhaust system usually has at least THREE (3) parts to it....a manifold or primary tubes, a "riser" and then a large rubber hose that acts as a "tailpipe" and is NOT jacketed.

A "dry" exhaust system is usaully a TWO (2) part system...the manifold or primary tubes, and then a one piece true tailpipe design and is when the water remains totally seperate from the exhaust gases as it moves throughout the entire exhaust system and finally is dumped at the very tip of the exhaust system or "tailpipe". Some people refer to the "tailpipe" as a "riser". A true tailpipe usually consists of a riser and tailpipe all in ONE PIECE and is double walled water jacketed pipe within a pipe and dumps the water totally seperate from the exhaust or at the very end tip of tailpipe. This is what makes it a "dry" exhaust system and will not allow water to revert and can use a cam with more duration, etc.

Wet or Dry, a person should be able to lay their hand anywhere on the exhaust system without getting a burn injury or burning the boat down.

Now I'll bet you're really confused! Whew....time for this Yank to go to bed.

chris-jack

your explainations are always great - thanks.