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Old 01-18-2021, 08:11 PM   #18
flatjack9
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Join Date: May 2010
Location: Oshkosh, Wi
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Default Re: Manifold vacuum at idle... vs without...interesting observations

Quote:
Originally Posted by Hal Beatty View Post
And that myth just keeps perpetuating... every engine from the late '50's that I ever worked on used ported vacuum; long before emission controls entered the picture.

You say you are using the stock 94 carburetor. If it was the one used with the Load-a-Matic distributor it has different passages for the dist. vacuum and will give you a venturi vacuum signal.
No myth involved. Ported spark was developed to reduce exhaust emissions. I worked on engine development in the auto industry in the 60's and 70's. Ported spark was a way to reduce hydrocarbons before better systems were developed. Back then, engines didn't run worth a damn because of this and other attempts to reduce emissions.
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