Quote:
Originally Posted by dcdoug
What's the main benefit of the secondary metering block and the second idle mixture screw, by the way?
|
The short answer is "if you car runs well, then there is no benefit to a secondary metering block."
Secondary metering blocks let you change the jetting, but if your metering plate is "just right," then there's no point in changing anything. Personally, I like my 4160 along with the metering plate (which has non-adjustable metering orifices). 4150s also have dual accelerator pumps -- some people love that. BTW, some people just think that mechanical secondaries are inherently superior to vacuum secondaries, but I am of the opinion that a properly tuned vac secondary is just as good, and sometimes better, than a mechanical setup. Two idle screws are needed because there are two idle squirters for the two primary venturis -- (some carbs have four). Two are easy to adjust, and you move them in unison. I use a vacuum gauge, and have for decades, but I'll readily admit that an gizmo in your sidepipes to measure the burn is superior.