RXT-X 255 2008 - How much water is consumed by the exhaust gas system ?

[jannie.loubser]

In the Tech Manuals I see reference to 4 x 0.138" holes that feed open circuit cooling water into the exhaust gas (This is the lake water fed by the jet pump to cool the intercooler, inlet manifold, exhaust muffler and exhaust gas, not the closed circuit coolant that is pumped through the drive plate).

1. I am interested to know what fraction of this water flow finds itself into the exhaust gas vs what returns to the lake. Any idea what the overall flowrate of the open circuit lake water is for a given rpm ?

Thanks,
Jannie Loubser

 

[Dennis]

I don't have a clue about the flow rate. The amount of water that exits thru the 4 holes in the end of the exhaust pipe (into the muffler) is about the same that exits thru the water return hose out the back of the ski.
4 times .138 in. is .56 in which is about the same size as the water return port in the pipe. Why do you need to know?

DAWG

 

[jannie.loubser]

Thanks Dennis for reply

Dennis,

I am actually using the Seadoo as the basis for a hovercraft and will be using the engine to drive a thrust propeller. Bottom line is that the craft will not necessarily be in water and that I have to make alternative cooling arrangements for both the engine and the exhaust system. The engine is closed loop and I can deal with this via a radiator.

I cannot easily make the exhaust cooling system 'closed loop', as I have to pick up from the water return pipe, as well as from from the exhaust pipe, which is not so easy. I am investigating the option of blanking off those exhaust holes in the exhaust, but will then have to provide additional cooling some other way.

I wonder whether the water in the exhaust stream was predominantly for cooling or played a role in exhaust pressure, as I imagine a portion of the water would vaporise quickly and enlarge the volume of of exhaust 'gas' leaving the pipe...?

Thanks,
Jannie Loubser

 

[daverade]

dude wow... leave it in the hull, it will go way faster on the lake..... super cool about the hovering, you should post up some pics i gotta see this?