holley carb secondary springs



holley carb secondary springs

Postby grumpyvette » December 3rd, 2012, 2:14 pm

look at the picture and chart ,notice the springs have a dab of paint to indicate the approximate resistance they provide
http://www.jegs.com/p/Holley/Holley-Vac ... 7/10002/-1
http://www.jegs.com/i/Holley/510/20-73K ... tId=743677
http://www.jegs.com/i/Holley/510/20-73/ ... tId=743677
http://www.holley.com/135-2.asp
https://www.youtube.com/watch?v=4xOiJQj6CSU
http://www.hotrod.com/techarticles/600- ... lications/

HERES WHAT THE HOLLEY TECH GUYS SUGGEST
"The Holley secondary springs regulate the opening point and rate on a vacuum secondary Holley based on venturi air velocity. When dealing with a vacuum secondary carb, keep in mind that they will not open in park or neutral. The engine must be under a load. Place a paperclip on the secondary rod horizontaly and slide it up to the base of the secondary diaphragm housing. Drive the vehicle under full load and check the position of the clip. if it is pushed down they are working. If not check the diaphragm and gaskets for damage and clean the vacuum ports. Also keep oin mind that they may not open if the carb is too large for the engine or if the spring is too stiff. To increase the secondary opening speed install a lighter spring. the common spring kit (20-13) will include 7 springs the following list is from heavy to light. Black, Brown, Plain, purple, yellow, short yellow, and white. I recommend starting with the black spring and working your way down. When you can feel the secondary come in (kick) go back to the previous spring."

When the spring is to light, the secondaries open to easily and create a lean condition, thats the bog you'll sometimes cause if the secondaries open to fast , especially if the accelerator pump and power valve are not matched to supply adequate fuel to cover the otherwise lean condition, faster opening secondary's may cause.. If you have a secondary metering block, make sure you have a p/v that will just stay closed at idle in gear. The sooner it opens on loss of vacuum the sooner it opens to flow fuel in to the plenum too cover the lean condition.

Example:
If you make 7"-8" of vacuum at idle you should be able to get away with a 6.5 p/v that will stay closed at idle, but open right with the secondaries. A 3.5 would have to wait for the vacuum to drop to 3.5" before it opens, and that 'wait' is a lean spot.

holley carb secondary springs
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IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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