Posted by Cowboy (IP: 216.161.250.98) on May 28, 2000 at 20:37:52:
In Reply to: Holley Carb tuning assistance needed posted by Mavman on May 28, 2000 at 18:56:14:
The one thing I can think of is the power valve, it's the thing that screws into the front metering plate. It opens up with the loss of manifold vacuum to richen the mixture. You should take a manifold vacuum reading as close to the base of the carb as possible then choose a valve that will open at about 2in of mercury lower than that with an automatic, 1-1.5 with a manual. lots of people overlook this especially when making cam changes and timing adjustments. All of wich can effect when this valve opens. I have seen them stay open at idle to for the lack of vacuum.
: What I have is a Holley 0-80457S 600 vac secondary electric choke. It idles fine. Just need a little advice on tuning. On the advice of my local speed shop man, I have the big blue accel pump cam, and have gone with 66 jets. I'm thinking that this is probably too much. It bogs a bit off the line, but will open up pretty well once into the RPM a bit. I have installed the quick change vac secondary spring kit, and probably need to make a spring change. I've also opened the secondaries a bit to aid in idle, and off idle. Seemed to have helped a bit, just concerned about the drag off the line. Also thinking that a stall converter might help. This thing has the stock converter, well...a stock type converter. It has been changed, but is the same as stock. Any assistance would be greatfully appreciated. Email would be nice due to it being so close to the end of the month.