390 Holley on a flathead

Ol' Ron said:
You might be surprised to know how well it could run if properly tuned.
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I agree. After a recent tune-up with new points, plugs and economizer valve, my '40 with a 390 has never run stronger or smoother. As the good 'ol boys down here used to say, "She runs out real good."
 
flatjack9 said:
That port does not give the proper signal to the distributor. It is the same as manifold vacuum, except it is closed off at idle.
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That's what I was always told too.....unless you're running the original 2 bbl it's not working properly with the Load o matic.
 
Thanks for all the input so far.

The engine is equipped with a converted SBC distributor and a 12 volt system. Vacuum advance is hooked up to the carburetor's timed spark vacuum source.

I have an electronic fuel pump running inline between the tank and the mechanical fuel pump, but with the pump both on and off the result is the same. I can only get the engine to run for a few seconds.

Never adjusted the float bowls - unfortunately, the instructions say that the car has to be idling to make that adjustment. Does anyone have a method for doing it while the engine is off?

Thanks again,
Nick
 
flatjack9 said:
That port does not give the proper signal to the distributor. It is the same as manifold vacuum, except it is closed off at idle.
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Perhaps you should contact Holley and tell them that the information they provide with thier product is false (I know I'm not going to)
 

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They are providing the correct information. The timed port as they call it, simply means that it is closed at idle and is opened as the throttle plate opens and exposes it to manifold vacuum. The loadamatic distributor takes it's vacuum signal from a combination of manifold vacuum and venturi vacuum which is only available on the correct 94 2 bbl carbs.
 
I think where the confusion here is is the fact that the vacuum advance for the Load o Matic DOES NOT function like a standard vacuum advance distributor. Yes, you are pulling vacuum like that Holley was designed to do on any other engine/vacuum advance distributor combo but not with the stock distributor.....it's a different animal all together.

Flatjack 9 has it right.
 
Finally just pulled the carb off and am in the process of rebuilding it. Does anyone have a recommendation for which power valve I should use?

Also figured I'd run 50 jets.

Thanks,
Nick
 
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