Author Topic: M4mE California emmissions Chevy 350 Chevy c20  (Read 3425 times)

Offline Cfrench192

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Re: M4mE California emmissions Chevy 350 Chevy c20
« Reply #15 on: July 15, 2016, 06:55:13 PM »
I can get 20 inches of vacuum with this cam at idle.  It's around 15 inches to prevent missfiring.  The cam was chosen by a machine shop.  The machinist knew that this truck needed to pass smog.  The cam he chose for me was a cam that was able to pull the necessary vacuum in the manifold.  That's why I'm believing that this is a fuel issue.  The carb I bought from summit may have been calibrated for a stock 350 cam.  However I really have no idea.  The truck hates hot days.  It loves cold days.

Offline Cliff Ruggles

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Re: M4mE California emmissions Chevy 350 Chevy c20
« Reply #16 on: July 20, 2016, 04:20:41 AM »
What are the cam specs, advertised, .050", lobe separation, etc?

Difficult to provide specific advice on commercially "remanufactured" carburetor, because they "butcher" them up and change most of the items involved with the calibration.

One BAD habit I see with them is opening up the lower idle airbleeds to HUGE dimensions then putting in huge idle tubes to compensate.

71 jets would be pretty small for on of those carburetors, but I don't know the MAB size it may have been changed from stock?.....Cliff