HOLLEY CARB power valves

grumpyvette

Administrator
Staff member
http://www.chevyhiperformance.com/techa ... index.html

it helps a great deal to know what your working with , each carb has good and bad points

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HOLLEY


" It Does (QUOTE)

Most carburetors employ what is generally called a power valve circuit. This circuit enriches the air-fuel mixture when the carburetor goes to wide-open throttle (WOT). At WOT, intake manifold vacuum drops to almost zero. When this occurs, the power valve opens and directs more fuel into the main power circuit, in addition to fuel delivered by the main jets. The Holley power valve employs a small rubber diaphragm that is opened by a small coil spring. The valve is held closed whenever sufficient engine vacuum is present. At WOT, engine vacuum disappears and the power valvespring opens the valve, directing fuel through a small, precise orifice in the metering block called the power valve channel restrictor. This restrictor determines the amount of additional fuel delivered to the engine.

Power valves are used most frequently on the primary side of a Holley carburetor. They allow the carburetor to operate with much leaner main circuit jetting for part-throttle fuel economy. Then, when the throttle is slammed open, the power valve adds additional fuel, creating the rich air-fuel ratio needed for WOT operation. Most Holley power valve circuits are designed to add the equivalent of 8 to 10 jet sizes of additional fuel. Holley does offer a power valve block-off part that closes the power valve circuit, but this means the jet size must be increased in order to compensate for the lost power valve circuit fuel. Imagine how bad your fuel mileage would be if you had to add 10 jet sizes to the primary side of your carburetor!"



http://www.youtube.com/watch?v=6vKlAnKdcB4&fmt=18

viewtopic.php?f=81&t=1189&p=2447#p2447

viewtopic.php?f=44&t=773&p=1309#p1309

http://www.mortec.com/carbtip1.htm

http://www.summitracing.com/parts/MOR-65222/?rtype=10

http://www.visn2.com/UsingVacumeGauge.html

http://www.bob2000.com/carb.htm

viewtopic.php?f=44&t=773&p=1123#p1123

http://www.valvoline.com/carcare/articl ... 4&scccid=1

http://www.holley.com/TechService/Library.asp

viewtopic.php?f=38&t=1099&p=2152&hilit=volumetric#p2152

High Flow Power Valves are intended for Alcohol applications while Standard are intended for Gas applications and a Gas application will not benefit from the use of High Flow Power Valves and in fact would run worse not better. So for gas applications stay with the Standard Flow Power Valve.
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HOLLEY ACCELERATOR PUMP CAMS

YOU REALLY SHOULD WATCH THESE SHORT VIDEOS

http://www.youtube.com/watch?v=eiRIfcrc2yA

http://www.youtube.com/watch?v=k-Nx5HEzvlY
these come in handy

holleypowervalvesq.jpg

holleyjetpack.jpg

holley2011.jpg

holley2012.jpg

If your tuning a holley carb having the 50cc accelerator pump kit and a selection of accelerator pump cams, a set of jets, squirters,and power valves in your tool box and a decent vacuum gauge, to tune with is a big help at times


jetpack.jpg



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VenturiVacuum01.jpg


http://store.summitracing.com/partdetai ... toview=sku
hly-20-12_cp.jpg

http://store.summitracing.com/partdetai ... toview=sku
http://store.summitracing.com/partdetai ... toview=sku
http://store.summitracing.com/partdetai ... toview=sku



hly-20-11.jpg

http://www.summitracing.com/parts/HLY-20-11/


http://www.holley.com/data/TechService/ ... uretor.pdf

http://www.holley.com/TechService/Library.asp

don,t forget the accelerator pump itself can be upgraded from 35cc to a 50cc version on many holley carbs

http://www.stockcarracing.com/techartic ... index.html

http://www.holley.com/types/Accelerator ... 0Parts.asp
Holley20Cam20chart.jpg

Holley Accelerator Pump Cam Chart

This chart gives the pump shot volume in CCs for each cam in each position.

Position 1 Position 2
White 17 19.5
Blue 18 20
Red 18.5 20
Orange 19 24
Black 19 18
Green 24 30
Pink 30 37.5
Brown 36

http://store.summitracing.com/partdetai ... toview=sku

don,t forget the squirters or discharge nozzles

hly-121-31_m.jpg


http://store.summitracing.com/egnsearch ... toview=sku

http://store.summitracing.com/egnsearch ... toview=sku

http://holley.com/data/TechService/Tech ... 20Info.pdf
(READ PG 4)

http://www.automedia.com/Holley_Carbure ... 000718hm/1

http://www.nationaltbucketalliance.com/ ... /carbs.asp


http://www.daytona-sensors.com/tech_tuning.html


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