OK - here are my ideas for quietness: Buy a new silencer, in fact if you really want quiet, putting an extra one in the chain really helps - done that with Kismet and it just purrs.
If the air outlet is in the side of the hull, then that should be OK, but I understand that air inlets are often taken from inside the boat. By putting another hole in the other side of the boat (and possibly ducting it downwards if necessary) should help. Now the bit that will make the most difference, put soundproofing material on all engine space internals - including the hull sides (though putting it in the bilge might be a bit difficult, and not such a good idea). We bought some at the Crick boat rally that was made up of layers - a hard wearing cover, over hard foam, with a hard rubber section in the middle. We can hold a conversation going at 2200rpm without problem. Also ensure that the flooring is fairly snug, and doesn't have holes around the edges. This will get rid of most of the direct noise, the rest will be vibration. Modern engines are mounted on rubber(?) engine mounts to reduce this. I don't know if older slow revving engines can also be put on mounts, but it might involve major surgery to the engine bearers, so I think it will be best to live with it. Just a note on engine bearers, ensure they are structurally secure, and are braced to the side. Shoestring suffers from extra vibration thanks to poorly braced bearers, there is nothing stopping them wobbling side to side: http://shoestring.zapto.org/pics/EngineOut/pages/PICT2053_SR3.html Oh, and another thing - ensure the engine has been installed correctly, and squarely. Apperantly mine was quite a bit out of whack! All the best, Mike On 8/15/06, Iain Street <[EMAIL PROTECTED]> wrote: > Ron Jones wrote: > > Ann wrote: > > > Here I am asking for help and advice again :-) > > > > > > The restoration of Bluebell is continuing (see > > > http://www.bridge19-40.org.uk/ link New Boat) and now that the > > > engine is running, we realise just how noisy a Lister in a cruiser > > > stern with absolutely no sound insulation is. > (snip) > > Oooo, what sort of Lister? Not renound for their quietness are they! > > The less number of cylinders then the more the vibration and noise - > > it doesn't really smooth out until 4 cylinders or more. > (snip) > > It's an SR2, on hardwood engine mounts. The current silencing arrangements are > a very basic silencer, which I re-covered as it had several large holes in it. > -- > Iain > > > > > > Yahoo! Groups Links > > > > > > > > -- Michael Askin http://shoestring.zapto.org/ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/canals-list/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
