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Exhaust Scavenging

Posted By: Char Baby

Exhaust Scavenging - 06/10/18 01:12 PM

Yes, I've looked this up but, find too much mumble/jumble.
Can someone explain in more simple terms of what exhaust scavenging is/dose...without writing a book?
Or is there too much to detail in order to explain briefly?

Thanks,

CB
Posted By: ragtoplvr

Re: Exhaust Scavenging - 06/10/18 01:27 PM

Ever shut a faucet too fast and have water hammer?
Enough energy in the inertia of the flowing water to shake the pipes.

Flowing exhaust has energy too. Using that energy to enhance the flow is able to pull more exhaust out a closing valve. or on an opening valve on an adjacent cylinder.

Rod
Posted By: PimTac

Re: Exhaust Scavenging - 06/10/18 01:38 PM

https://youtu.be/rNtS8qyjIJU

Skip to around 2:50 in the video.
Posted By: Char Baby

Re: Exhaust Scavenging - 06/10/18 01:41 PM

Originally Posted By: ragtoplvr
Ever shut a faucet too fast and have water hammer?
Enough energy in the inertia of the flowing water to shake the pipes.

Flowing exhaust has energy too. Using that energy to enhance the flow is able to pull more exhaust out a closing valve. or on an opening valve on an adjacent cylinder.

Rod


Perfect, thanks!
Posted By: BrocLuno

Re: Exhaust Scavenging - 06/10/18 04:58 PM

That's an apt description, but in the case of exhaust, it's frequency dependent and usually does not start until north of 3,000 RPM ... It is tune-able like a Pipe Organ tubes. Hence the search for the right length and size of collector tube and extension. It does not generate HP per se, but helps achieve more air flow and that helps with the HP.

There is a YT vid on Engine Masters where they test various exhausts and you can see the results compared smile
Posted By: CT8

Re: Exhaust Scavenging - 06/10/18 05:59 PM

Add to the exhaust tuning intake tuning. It is exactly the same but different.
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