L79 carb jetting
What primary carb jets would you empirically recommend for my '67 L79?I'm in MS., 264 ft. above sea level. Engine is stock except for a Comp Cams(I know, I know, Duke)cam, "vintage series"-slightly more duration than OEM cam, has stock Holley 4160 with stock #65 primary jets. Runs good but seems to have a slight surge toward redline.I run 92 octane non ethanol, with occasional 1/4 tank racing fuel. Without benefit of broad band O2 analyzer, would you richen, if so, how much? Thanks
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Re: L79 carb jetting
William,
If the engine runs fine at cruise speeds like 35-45-55-65 MPH, the mixture at WOT can be richened by enlarging the (PVCR) power valve channel restriction. This will allow more fuel when the power valve opens which is where you report the surge. I think the stock PVCR is .039, just remember if it's a original carburetor you can't make the holes smaller after drilling.
You can also change the secondary metering plate to a different Holley number with larger main jet restrictions. Only way to tell is ET speed or a dyno.
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