Exhausting issues

[ailsaboat]

Hi everyone. I've just become the proud owner of a 38' steel bathtub that hopefully wont bankrupt me too quickly. The first point I'd like the assembled masses opinion on is my exhaust.
As briefly as I can, the engine is roughly in the middle of the boat, the exhaust exits the engine on stb at sole level where it enters a 8inch thick wall(?) rises to cabin top level, where the water mixer is, before plumeting back to floor level then heading rearward for a good 12 feet where it connects to a swan neck/standpipe arrangement and exits under the hull.
My question is, is this a sensible arrangement?
I've been told it's a 'belt and braces' safety feature, but exiting under the hull I can't tell if water is coming out, the first thing I look for when starting.
My options as I see them are:
1,Make good 'as is'
2,Roughly as is, but remove the stand pipe and go for a through hull in the transom.
3,Remove it all, buy a 'vetus type' plastic water exhaust thingy and send it straight out the side of the hull - saving about 20' of pipe.

Any other options or suggestions??
Cheers
Des

 

[boatmike]

How big is this engine and what is it? How much higher/lower is the exhaust manifold on the engine than the waterline?

 

[ailsaboat]

The engine is a 60hp Nanni (4cyl 2.2l) and the manifold is more or less on the waterline.

Hope my original message is understandable!

Ta

 

[macd]

Is there a vented loop between the heat exchanger and the point where the raw water joins the exhaust? From the sound of your levels, that might be a good idea. Vetus catalogues (and perhaps also their web site) have straightforward diagrams which should clarify what you need. I've just bought a Vetus vented loop, cost around £45, and straightforward (space permitting) to fit.

 

[ailsaboat]

At the moment there isn't anything, straight out of the heat exchanger, curving until it reaches the bulkhead (so thick and with a door, it's more like a cupboard!!) where it rises to cabin top level - loops over - water inlet- then back down before heading aft.
My main concern is whether to leave the final exhaust exit under the boat, or move it above the water line.
I've ordered the vetus catalogue to get some ideas.

 

[DavidMcMullan]

Is the rise through the cabin also acting as a heater for the cabin?

 

[ailsaboat]

Not specifically, although I suppose it must have some effect. It's lagged with heatproof fabric tape.