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Location:
Melbourne
Registered:
May 2002
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 Left of Field–Turbulence and throttle bodies
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Mon, 08 August 2005 13:49
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Fellow techo's
Has anyone given thought to the turbulence that the butterfly valve introduces to airflow and what possible altenatives could be designed?
Take a bottle of water, turn it upside down–see how fast it empties-glug, glug. Same bottle of water, instill in it a rotation by circular motion, turn it upside down and vortex will assist emptying.
Case study: 750 ml Wolf Blass Eaglehawk wine bottle.
Straight (glug) empty: 9.29 seconds
Vortex empty: 4.76 seconds
n=1
Liquid=water (just drank the wine 
Any thoughts?
David
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Mon, 08 August 2005 14:21
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Do a little bit of searching on the net, and see what you can find about flat slide carbs/throttles, barrel throttles, devices such as Hiclone, and the only one I believe to be truly full of merit, not having throttles, and draw your own conclusions.
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Location:
Melbourne
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Mon, 08 August 2005 15:27
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hummm,
well I've now looked, any URLs you like best? I feel sad for NA folks, tuning carbs. I use gas there4 vaporiazation is not primarily the issue. Some turbulence is needed for volatile liquid vaporization, poor folks.
The Hiclone device installed after a butterfly valve/throttle was closer to what I had in mind and seems feasible provided enough length is allowed to regularise the flow and some resistance is allowed. But what I'm suggesting is an alternative to restricting flow that leaves at least a lesser non-turbulent air flow after the 'valve'/throttle. Sure bugger up the air flow via a throttle and then try to 'regularize' it via Hiclone type device. I can't draw my own conclusion as I haven't tested Hiclone, I wonder if anyone at Toymods would have chanced their $$s and are humble enough to admit and share their results??? Come on!
It would seem to me a 'generic' vortex unit would be hit and miss.
I would imagine swirl combustion chamber designs were designed for a reason and these could be enhanced by the gas stream entering the chamber in a regular, predictable manner. Better efficiency in inlet flow could imaginably be achieved if more attention was given to either eliminating or reducing turbulence due to butterfly/slide valves by using a more advanced technology vs 'conditioning' the airflow afterwards (which could be a good thing!). I have in mind something but am working on it A lot of effort has been put into liguid fuel injection (when it would be a lot easier just to burn gas-perhaps liguid gas injection excluded)
David
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Location:
Brisbane
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 00:15
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Swirl ports have been around for a long time, and they work great on low-rpm high-torque engines but become a major restriction if you try to rev the engine hard. For high rev, high performance applications you need a straight clear path from the inlet system to the combustion chamber. Remember you only have a small fraction of a second to get X cc's of air past the valve and into the cylinder, and at high rpm this window becomes very narrow indeed!
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Location:
Perth
Registered:
January 2005
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Location:
Brisbane
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 03:06
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It's not that hard to eliminate turbulence around the throttle plate, just use slide or barrel throttles as used on some motorbike and race engines. Not as simple or reliable as a conventional butterfly arrangement, but it completely eliminates any flow restriction at WOT.
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 03:18
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Simple solution
Step 1: Remove throttles
Step 2: Remove cams
Step 3: Install variable solenoids to control valves
Step 4: Program ECU
Step 5: Enjoy the fruits of your labour.
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Location:
Brisbane
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 03:47
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| CrUZsida wrote on Tue, 09 August 2005 13:18 |
Step 1: Remove throttles
Step 2: Remove cams
Step 3: Install variable solenoids to control valves
Step 4: Program ECU
Step 5: ???
Step 6: Profit.
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Fixed.
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 03:51
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I was going to do that, but its getting old, so I moved on.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 04:15
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| Gased wrote on Mon, 08 August 2005 23:49 |
Fellow techo's
Has anyone given thought to the turbulence that the butterfly valve introduces to airflow and what possible altenatives could be designed?
Take a bottle of water, turn it upside down–see how fast it empties-glug, glug. Same bottle of water, instill in it a rotation by circular motion, turn it upside down and vortex will assist emptying.
Case study: 750 ml Wolf Blass Eaglehawk wine bottle.
Straight (glug) empty: 9.29 seconds
Vortex empty: 4.76 seconds
n=1
Liquid=water (just drank the wine
Any thoughts?
David
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i think it will empty faster if you break the bottom off the bottle then no glug 
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Location:
Brisbane
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 04:21
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| CrUZsida wrote on Tue, 09 August 2005 13:51 |
I was going to do that, but its getting old, so I moved on.
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BAM!!
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Location:
Canberra
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 05:34
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David, if you are using LPG, get a "Gas Research" Carb they operate on the slide principle, rather than the buterfly.
cheers Chuck.
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Location:
Melbourne
Registered:
May 2002
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 Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 10:44
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Thanks n all,
I'm off trying to find a diagram of a slider carb, never seen one.
Regarding swirl chambers–what I was getting at is if the air within the intake above the valve swirled it would get past valve and into head quicker. The Hiclone is _towards_ what I was thinking of–vanes to get turbulent air regular again. An airfoil butterfly would be better but only at full throttle. Best not to have a throttle valve at all (as I'm being told slider carbs don't) If air travelled centrifugally in inlet ports it would travel faster. While the Hiclone looks interesting I would want to see some real proof of operation.
On a tangent–smooth isn't always best. I've been told a fine mohair jumper, believe it or not, offers less wind resistance than lycra when riding a push bike–it just get bloody hot fast wearing one. Have been told its about 'boundary layers' and laminar flow.
Knitted intake liners...mum? 
David
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 13:28
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Yes, but you have to remember that certain principles apply to certain applications - to quote a friend of mine years ago: (we were starting at an XA Falcon wagon) 'I'm gonna get one of these, cover it in fibreglass and put dimples on it like a golf ball. Then I can go really fast and have no wind resistance.' Come to your own conclusions.
Gas Research carbs are NOT slide throttles, or anything even remotely that classy. Still, if you're a fellow gas nut, why not PM me and we can spend hours talking about silly ideas that other people laugh at...
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 13:48
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| Gased wrote on Tue, 09 August 2005 20:44 |
. Have been told its about 'boundary layers' and laminar flow.
Knitted intake liners...mum?
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you mean rough sandcast finish on intake ports perhaps?
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 14:34
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The knitted ones seem so much more homely...
Plus they provide a handy way to catch all that nasty oily scum!
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Location:
1st street on the right
Registered:
November 2002
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Re: Left of Field–Turbulence and throttle bodies
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Tue, 09 August 2005 21:50
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What if there was a flap like an AFM instead of a pivoting butterfly that remained in the airpath?
Then as River suggested shape it to create favorable pressure systems in the flow.
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