Innovative Designs ''Stacker'' Venturi
09-15-2010 | 07:56 PM
#16
Suspended
iTrader: (7)
Joined: Aug 2010
Posts: 609
A taller venturi makes the "intake runner of the engine longer - the distance from the restrictor's "trumpet" or "mouth" to the rotary valve in the crankshaft. Since, the pulse waves that travel through it need more time to do so making tune at a lower rpm setting thus giving better power at low - mid rpm range.
In other words, same as long or short pipe/header.
same as pipe: long(tall) for short tracks, short for long tracks.
Actually, the gasses traveling through the intake runner and exhaust when tuned (when both have the correct length for each other) correctly "think" that both trajectories are equally long, the physical difference being "disguised" by the fluid's temperature.
xe
In other words, same as long or short pipe/header.
same as pipe: long(tall) for short tracks, short for long tracks.
Actually, the gasses traveling through the intake runner and exhaust when tuned (when both have the correct length for each other) correctly "think" that both trajectories are equally long, the physical difference being "disguised" by the fluid's temperature.
xe
09-15-2010 | 11:54 PM
#17
Intake runner length is measured below the carb 
Hilborn Injection uses injector length to tune airflow deficiencies due to irregular intake runner lengths.... long ones go on the short runners to SLOW the airflow
If anything make different length heat dissipating carb sleeves (installed below the carb) different lengths, that would allow a usable tuning difference.
We're dealing with ultra high RPM "diesels" not a std 2 stroke gasoline engine and full scale automotive race engine. Dynamics that are present in our R/C engines are not present in full scale. I worked for a nationally renoun cylinder head builder here in town for 8 years (contracts included Yates and Hendricks)..... flowbench and dyno is all we did
Hilborn Injection uses injector length to tune airflow deficiencies due to irregular intake runner lengths.... long ones go on the short runners to SLOW the airflowIf anything make different length heat dissipating carb sleeves (installed below the carb) different lengths, that would allow a usable tuning difference.
We're dealing with ultra high RPM "diesels" not a std 2 stroke gasoline engine and full scale automotive race engine. Dynamics that are present in our R/C engines are not present in full scale. I worked for a nationally renoun cylinder head builder here in town for 8 years (contracts included Yates and Hendricks)..... flowbench and dyno is all we did
09-16-2010 | 07:10 AM
#18
Tech Regular
Joined: Apr 2009
Posts: 380
This is true for a multi-cylinder engine with a common intake manifold, where an "atmosphere" is created and where the pulse waves from the tuned runner length can work with. On a single cylinder engine like ours the runner is from the top of the restrictor to the crank valve, and the atmosphere plays its role as it is.
runner length ends where a sudden big change in cross sectional area is, and starts with the valve.
I would love to have your job
that's got to be a daily school!
xe
runner length ends where a sudden big change in cross sectional area is, and starts with the valve.
I would love to have your job
that's got to be a daily school!xe
09-25-2010 | 06:25 AM
#22
I can see where they changed the venturi up a bit but i would like to see a venturi that has something like this:
http://www.summitracing.com/parts/TAM-KI-80/
http://www.summitracing.com/parts/TAM-KI-80/
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