Dry Exhaust systems. 2 into 1?

[DBA Forum (B) - Steve Graves]

I have just fitted a 4" dry exhaust system to my main engine and am considering taking the 1.5" dry exhaust from the generator and feeding it into the 4" pipe. I intend to angle it to flow up the pipe. I do not intend to run both together. Has anybody come across this before or know of any pitfalls. I would appreciate any advise.

Thanks

Steve

[DBA Forum (B) - Frank Kordbarlag]

Where are the silencers? Before or after the union? After the silencer should be fine, before is tricky because engines need a little back pressure from the exhaust, which is different for each engine.

Frank

[DBA Forum (B) - John Booker]

Steve,

I think that it is generally accepted that what you propose is very bad
engineering practice, which is why you will never have seen it done. I
have heard of installations where non-return valves were used in the
pipework to prevent the problem which arises from this practice, but
these valves were too troublesome to be practical.
The issue, as I understand it, is that condensation will occur in the
engine which is not running. The condensate from exhaust gas is quite
acidic, despite low sulphur fuel, and this acidic condensate causes
rapid corrosion of cylinder bores and piston rings. It would therefore
be far cheaper to pipe up a separate exhaust to the generator than wreck
your main engine.

Regards

John Booker

Post by DBA Forum (B) - Steve Graves
I have just fitted a 4" dry exhaust system to my main engine and am considering taking the 1.5" dry exhaust from the generator and feeding it into the 4" pipe. I intend to angle it to flow up the pipe. I do not intend to run both together. Has anybody come across this before or know of any pitfalls. I would appreciate any advise.
Thanks
Steve

[DBA Forum (B) - Colin Stone]

A good idea on initial thoughts and why didn't I do that?
But on thinking I would have thought backflow through the non running engine and out of the air intake filling the space with fumes would be a more immediate problem. Some of the inlet and exhaust valves are bound to be open at the same time.

Colin Stone
KEI
Sent via BlackBerry® BIS

[DBA Forum (B) - Steve Graves]

Thanks for your responses. I think there is a potential for back flow through the non running engine. I am still considering the angle required to bring in the second exhaust and eliminate this. It will be after the silencers and in the final vertical exhaust pipe

Thanks again

Stev