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 Post subject: Swirl direction???
PostPosted: Mon Oct 30, 2017 8:23 am 
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998cc
998cc

Joined: Mon Apr 05, 2004 11:23 am
Posts: 580
Location: Eastern Melbourne
Supplemental to my injector question, however....

A: Which way CW/CCW does each cylinder swirl?

B: At what RPM does the swirl become tumble? (allows me to multi injector fire)


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 Post subject: Re: Swirl direction???
PostPosted: Mon Oct 30, 2017 6:46 pm 
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1275cc
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Posts: 5370
Location: Yandina,Sunshine Coast,QLD
I don't know, but are we talking about swirls in the compression stroke?
Dose the inlet manifolds affect any of this?
Interesting topic I've never really got into.

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 Post subject: Re: Swirl direction???
PostPosted: Tue Oct 31, 2017 7:47 am 
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998cc
998cc

Joined: Mon Apr 05, 2004 11:23 am
Posts: 580
Location: Eastern Melbourne
It's on the inlet stroke. two valve heads generate a swirl where 4(+) valve heads tumble with efficiency cross over around 4000rpm (stroke/bore ratio dependant). Im assuming the swirl in the mini 5 port is both CCW/CW due to the Siamese ports with the direction correlating to the tangential momentum of air-fuel to the cylinder circumference. But that's only an assumption.
If I can shoot the fuel from each injector to suit cylinder fill, I can smooth out the rich/lean bias. I'm also considering smaller injectors and concurrent firing at higher demand. If I can poke holes in my thoughts now it'll save some coin later.


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 Post subject: Re: Swirl direction???
PostPosted: Tue Oct 31, 2017 6:05 pm 
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1098cc
1098cc

Joined: Wed Nov 24, 2004 10:23 am
Posts: 1488
Location: Armidale, NSW
I figure looking from the inlet port side from the top of the cylinder:
1 CW, 2 CCW 3 CW 4 CCW.
But that's just a slightly educated guess that most of the charge goes in the backside of the valve and will turn around as it encounters the cylinder wall.

I suppose an injector fired at the valve would have to help somewhat with charge robbing and maybe firing cylinders 1 and 4? slightly later.

It was an idea I had some time ago, swap the exhaust and inlet ports, so you have 3 inlet ports an 2 exhaust ports, cylinders 2 and 3 then share the middle port but are separated so charge robbing would be minimal. The exhaust might not be optimal however... You would have a charge go out the port immediately followed by it's neighbour which might result in some scavenging happening?
You would need a pretty different camshaft though.

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 Post subject: Re: Swirl direction???
PostPosted: Thu Nov 02, 2017 10:07 am 
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998cc
998cc

Joined: Mon Apr 05, 2004 11:23 am
Posts: 580
Location: Eastern Melbourne
Ok updated the cranium to one injector per cylinder (2 per port), dumped the concurrent firing.


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