Operation exhaust silencer:I had a look at commercially available silencers, but decided to make my own. (Like most things on this project.) I like experimenting a bit, put my signature on the project and at the same time save some money.
Been keeping my eyes open for the last week or so for a suitable piece of pipe as a casing, when it suddenly struck me that an old fire extinguisher would work just fine for this purpose.
Exhaust flange: Cut from a piece of 12mm plate. Hole bored out on the lathe. Used the original exhaust flange as a template.
I picked up the old extinguisher for a few bucks from an extinguisher service station. Spend quite some time to grind off the fittings and also the ring it stands on. Added bonus that it now has a nice rounded bottom. I offset the inlet from the bottom up to reduce the height, and also offset it to the side to get the silencer away from the air cleaner - notice the oblong side hole to achieve the lateral offset.
The intake baffle:Millions of randomly drilled holes.....
Trial fit:Next step will be to cut the top off and make some (I think 3) chambers and baffles. Plenty more holes to drill
Still not sure what packing material to use. I'll give the exhaust shop a call and find out if they've got something. I have some ceramic heat blanket, but after some Google searches I gave up on that idea. Apparently there are some health concerns with fibers that dislodge over time and gets blown into atmosphere. Steel wool burns... pot scrubbers can work, but I'll need to buy a whole bunch of them and that will be a very uneconomical solution.