New Holley 4 bbl
Just purchased a 87 Minnie that the previous owner had a New Holley 4 bbl recently put on, went to get the rig smogged and the tech said it was running too rich and it didn't pass. When he did the H...
Forum Discussion
You might see if there is a third party replacement for the Holley that is more tunable (I'm thinking Edelbrock) but even that is going to require some expensive dyno time to get the jetting right for the pattern of use.
Living in California, dealing with CARB emissions standards and testing, can be a pain. In the carburetor era, it was hard to do a tune lean enough to pass emissions when the "solution" was lean burn technology, and still be rich enough under load to function well. U.S. carburetor designs simply did not have enough mixture control flexibility to meet the full. range of needs, particularly for trucks. That led the industry to electronic fuel injection and feedback loops in the control programs, abandoning lean burn for catalytic conversion, which for NOx control needed mixtures rich enough to provide useful power with a little bit fuel cooling.
Living in California, dealing with CARB emissions standards and testing, can be a pain. In the carburetor era, it was hard to do a tune lean enough to pass emissions when the "solution" was lean burn technology, and still be rich enough under load to function well. U.S. carburetor designs simply did not have enough mixture control flexibility to meet the full. range of needs, particularly for trucks. That led the industry to electronic fuel injection and feedback loops in the control programs, abandoning lean burn for catalytic conversion, which for NOx control needed mixtures rich enough to provide useful power with a little bit fuel cooling.
