I have a Aeromarine Cyclone, zenoah 23modded with wet tuned pipe,, currently have it stripped for paint, i wanna make a custom exhaust, to rid me of that ugly hole from the pipe,,, i want to install 4 exhaust ports on the sternboard,,stainless,,5/8" or so pipe,,,joined above radio box into one larger pipe,,,can it be done effectively,,, without taking away from hp,,

I think you could do this using an offset 3" 90degree header and running the pipe inside the left sponson back to the transom. Maybe even a 4" offset. If you're engine is far enough forward and your pipe will tune short enough, you should have the stinger inside the hull. You could then couple your stinger to the new manifolds with some Teflon tube. I would NOT run the pipe over the radio box for internal installation.

Some examples of parts you could use:

9x4br.64n2f.servertrust.com/Pr...ductCode=EX9054

9x4br.64n2f.servertrust.com/Pr...ductCode=EX9053

9x4br.64n2f.servertrust.com/Pr...ductCode=EX9045

thats great, I already have the header in the pic, with approx 3" offset..
What I am wanting to do, is make a 2 1/2- 3" or so main pipe, with 4 pieces of 1/2" exiting the boat,,2 on either side,,,i can then make an extension for the header pipe, to connect the Larger piece ,, i hope it will work,,

It will work I'm sure. I would use Teflon tubing to connect the pipe to the oulet manifold though... I know Rocket City racing sells that stuff in various size. It will allow a bit of vibration dampening while holding up to the heat.

If following your question ... If you keep the tuned pipe and make sure the combined area of the 4 outlets is greater than the area of pipes outlet at stinger, it will work fine with no power loss.

If on the other hand you wanting to REMOVE the tuned pipe and run exhaust out threw a muffler and 4 outlets, your going to likely lose performance.

:? So with that said, what was your exact plans ?

well,, i was gonna get rid of it,, unless i can cut it off shorter, and attach 4,,, 1/2 lines to it,,and run em out the back

sparky379 wrote:Nope ... that won't work.

well,, that just bites,,,i will have to live with the loss of power, because thats the look I am after,, the 4 scaled exhausts sticking out the back,,, I mean,, I dont race it, i am the only one for 70 miles with a boat,, i just want the look, i dont mind sparing on the performance a bit,,,

Keep the tuned pipe and couple it to the exhaust outlets. That's what I assumed you were doing. It can easily be done. Use a Wrap-to-forward header worse case. You will have plenty of room and get much better performance from that than from a straight muffler setup. One of those headers is in the links I posted earlier. I bet even a 3 or 3.5" offset 90 would work.

keep the pipe!

I would rather have a beat up butt ugly looking boat thats fast, than a good looking boat that performs like crap. but thats just me.