1937 346 basic tests

[Steve Passmore]

That's a fantastic article Bobby, clears up a lot of things but has little connection with one of the questions here.    It was asked if vacuum can be connected directly to the manifold somewhere or to the correct position at the base of the carb. Both of these positions would seem the acceptable 'Below the Venturi valve' position according to the article. The other anti-pollution era position above the valve is academic to the engine in question, but as Brad said, why change the Cadillac design?

[The Tassie Devil(le)]

The only Cadillac design worth changing is the Anti-pollution Era.

BUT, if one has to have the Anti-pollution stuff operational, then one is stuck.

Bruce.

[Glen]

I like to know the source of things like that, so I did a google search.  The article is on a lot of other car sites as far back as 2004.
-
Two sites cited the source as: 
John Hinckley
Retired GM/Chrysler Engineer
-
Several cited John Z
-
And one cited:
TIMING AND VACUUM ADVANCE 101 (from October/November 2003 issue of "Corvette Enthusiast" magazine, written by JohnZ)

One site had a lot of info after what was shown here.  Maybe part of the original article, maybe not. 
http://www.hotrodders.com/forum/vacuum-advance-hooked-up-directly-manifold-bad-47495.html
Glen

[jackworstell]

So then...I guess the Cadillacs of the 1940s ( and thru out the 1950s too I would suppose )   used manifold vacuum...not ported or venturi vacuum....for the vacuum advance on the distributor ?

Jack Worstell       jlwmaster@aol.com

[jackworstell]

So then....I guess the Cadillacs of the 1940s ( and I guess the 1950s as well )   used manifold vacuum .....and not ported vacuum or venturi vacuum....for the vacuum advance on the distributor       I say this based on reading the article posted above by Bobby B.    And then that would mean the opening at the base of the carbs for Cadillacs of this era is connected to manifold vacuum.

Jack Worstell        jlwmaster@aol.com

[jackworstell]

Bobby B

Thanks for the article on distributor spark advance .........the best I've seen.   I understand this much better now.

Jack Worstell       jlwmaster@aol.com

[Bobby B]

Bobby B

Thanks for the article on distributor spark advance .........the best I've seen.   I understand this much better now.

Jack Worstell       jlwmaster@aol.com

Everyone is welcome. It's written in layman's terms and easy to understand. In 2 minutes you unlock the mystery of how vacuum/advance works....
                                                                                                                                             Bobby