https://m.youtube.com/watch?v=JW21G0o1bdk
Statistics: Posted by jmarkaudio — Wed Mar 30, 2022 3:11 am
]]>
]]>
]]>
]]>
Try:
Obert's: Internal Combustion Engines and Air Pollution
Taylor's: Internal Combustion Engine in Theory and Practice link here: http://racingfuelsystems.com/viewtopic.php?f=11&t=122
Sir Ricardo's: The High-speed Internal-combustion Engine
Heywood's: Internal Combustion Engine Fundamentals
Blair's: Design and Simulation of Four-Stroke Engines
If you are really keen to understand this stuff then you start chasing a deeper understanding of "Combustion" because ultimately that's what we are all really trying to improve with our engines
Statistics: Posted by hysteric — Sat Apr 17, 2021 2:30 am
]]>
NACA TR 49 - Metering Characteristics of Carburetors
https://www.abbottaerospace.com/downloa ... rburetors/
"Effects of Air-Bleed Systems on Carburettor Performance"
Yasuke ASANO, Toshitaka CHUMA, Heiichiro HAGA, Tadahiro MOCHIDA
Overview: https://www.jstage.jst.go.jp/article/js ... 1/_article
Download: https://www.jstage.jst.go.jp/article/js ... f/-char/en
"Effects of Multihole Air-Bleed Systems on Carburettor Performance"
Yasuke ASANO, Ichiro ISOBE
Overview: https://www.jstage.jst.go.jp/article/ki ... 6/_article
Download: https://www.jstage.jst.go.jp/article/ki ... f/-char/en >> IN JAPANESE <<
Statistics: Posted by BradH — Wed Apr 14, 2021 7:41 pm
]]>
]]>
Also, two air bleed / emulsion research papers from Japanese research efforts in the '60s which I've found helpful. I know the first one was also referenced by Tuner in another thread somewhere years ago:
"Effects of Air-Bleed Systems on Carburettor Performance"
Yasuke ASANO, Toshitaka CHUMA, Heiichiro HAGA, Tadahiro MOCHIDA
Overview: https://www.jstage.jst.go.jp/article/js ... 1/_article
Download: https://www.jstage.jst.go.jp/article/js ... f/-char/en
It turns out there is also a "sequel" of sort, although I haven't found a copy that's been translated into English. Even though it's still in Japanese, I have figured out most of - possibly all - the key diagrams, but haven’t documented it anywhere at this point.
"Effects of Multihole Air-Bleed Systems on Carburettor Performance"
Yasuke ASANO, Ichiro ISOBE
Overview: https://www.jstage.jst.go.jp/article/ki ... 6/_article
Download: https://www.jstage.jst.go.jp/article/ki ... f/-char/en >> IN JAPANESE <<
I suspect people look at the publication dates of these and jump to the conclusion that they're no longer relevant. However, IIRC, the laws of physics and behavior of air & fluid flow haven't changed with the calendar, only the ease in which the data can be captured and analyzed.
//////////////////////
This is likely a "stickie" candidate, FWIW
Statistics: Posted by BradH — Wed Apr 14, 2021 3:14 pm
]]>
Thought it might be helpful to post what I've collected on vacuum secondary diaphragm opening rates.
Below are whatever springs I had loose lined up on bench. The free heights and
installed hieght in a Holley Quick Change vacuum pod were measured with a vernier caliper.
VacuumSecondarySprings-Heights.jpg
Taking the above height information and adding it to the Holley graph* reveals how changing the springs will effect opening point and rate relative to each other. For example, white and purple have similar opening points, but white will then fully open much quicker or with less velocity in the barrels. So this allows some tailoring of both opening point and how quickly the secondaries then continue open. Not sure why the black spring is non-linear. Maybe they all are, but the softer ones to a lesser degree.
VacuumSecondarySprings-ForceGraph-revised2.png
Secondary Spring Part Numbers and Opening Points
Holley Secondary Springs available for purchase.
I can't speak to how universal those opening points are. My own experience has been that WOT secondaries are not effecting power until higher in the rpm curve. However I suspect that may have to do with other factors specific to my carb and engine. A test for whether the secondaries opened is to attach a flag (paper clip or wire tie) on the stem.
Diaphragms
Last but not least, it helps to have the matching diaphragm for the carb.
holley04-Secondary-diaphrams.JPG
Secondary Diaphrams part numbers for Holley List numbers.
Probably from an older catalog
-------------------------------------------------------------------------------------------------
*In Urich's Holley Carburetor Handbook: 4150 & 4160 Selection, Tuning & Repair book and also in Urich & Fisher's Holley Carburetors and Manifolds and another version in Vizzard's latest Holley book. The Vizzard and Urich versions appear identical besides color and a minor difference in the purple and green spring rates.
Statistics: Posted by jmarkaudio — Sat Apr 25, 2020 12:22 am
]]>