Author Topic: Silencing a CS  (Read 3306 times)

AdeV73

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Silencing a CS
« on: August 25, 2009, 06:54:58 PM »
As those who have read some of my previous gumph may recall, I have a couple of Aston Martin exhaust silencers (pattern parts, as it happens, not OEM). For ages, I've been running with one stuffed in the end of a 90-degree elbow. Today, as I'm bored, I welded the two silencers together, propped them on a bit of wood, & stuck it back in the elbow, thus:



Each silencer is about 33" long, and approx 4" diameter; so with the tube in between & at each end there's about 6ft of exhaust pipe. Ignore the absolutely incorrect up-slope, this is a LONG way off being finished (I need a heatX in there as well).

Anyway, with that lashup in place, I cranked over the old girl... but she didn't seem to want to run. The flywheels went round, but I couldn't hear anything! It was spooky... and then I realised - she IS running, I just can't hear the exhaust any more!

Unfortunately, the whole thing is a bit unstable now, so I didn't dare walk away leaving the engine end unsupported, as it was bound to fall out... but even so, what an amazing difference.

So, I guess the moral of the story is: If you're having silencing difficulties, don't rule out pattern Aston Martin parts ;D  Any residual noise can be explained to your neighbours as a poorly DB6 that you're fixing up... ;)

jzeeff

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Re: Silencing a CS
« Reply #1 on: August 26, 2009, 03:47:30 AM »
So why are listers quieter than other diesels of similar HP?  RPM?  Size?  I'd like to understand the physics of it.