2 carbs/ vacuum advance

O

ollie

New member
Hello
I am thinking of using an Edmunds dual carb intake, progressive linkage, 94 carbs on a 1953 Mercury Flathead.
I have heard that dual carbs. might cause a vacuum loss to the Factory distributor? . Might have to change to a mechanical advance distributor?
Any advice on this change would be appreciated.
Ollie
 
The load-a-matic will not work with a two carb intake. The best option would probably be the Chevy conversion distributer with both mech and vacuum advance. Bubbas (and others) can provide the distributer.
 
ollie.

Yes the loadamatic distributor will not work correctly with a two pot set up. Performance will be poor and it will tend to run warmer than it would with a mech. advance distributor that has the proper curve for a flathead.
 
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ollie said:
Hello
I am thinking of using an Edmunds dual carb intake, progressive linkage, 94 carbs on a 1953 Mercury Flathead.
Ollie
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My experience using two carbs on a flathead has been that straight linkage is best, rather than one carb remaining closed until other is something like 3/4 open...... progressive. Others may agree or differ.
 
ollie said:
Hello
Would the MALLORY electronic with mechanical advance be a reasonable option?
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Anecdotal evidence says that the new Mallorys may have an improper advance curve for our engines. Yes you could buy one, but probably best to have the curve checked before you run it. Bear in mind that Mallory has been bought out by MSD so replacement parts may become an issue, just my .02.
 
JSeery said:
The load-a-matic will not work with a two carb intake. The best option would probably be the Chevy conversion distributer with both mech and vacuum advance. Bubbas (and others) can provide the distributer.
Click to expand...

Bubba's got the answer.
 
Just so everyone knows, there is a thread on the H.A.M.B. saying that Mallory (who was bought by MSD a few years ago) has been completely shut down by them.
 
Tubman - correct - MSD purchases Mallory, then Holley purchases MSD a few months
later. MSD will support Mallory with parts - just not building those Mallory dual points any longer. What does that do to the value of Mallory distributors? Mallory has had its share of owners. When I worked for Dana, they had purchased Mallory from Mr. Gasket. The plant in Sparks, Nv. was a mess. Poor quality, deliveries, etc. After DAna took it over, they turned it around, that was until Dana's management drove that company into the ground and its stock went to pennies. Dana dumped Mallory to raise cash. (dumped the division I worked for as well)

http://www.hotrod.com/news/1509-hol...ps-and-more-join-holleys-tree-of-speed-parts/
 
ollie said:
Hello
I am thinking of using an Edmunds dual carb intake, progressive linkage, 94 carbs on a 1953 Mercury Flathead.
I have heard that dual carbs. might cause a vacuum loss to the Factory distributor? . Might have to change to a mechanical advance distributor?
Any advice on this change would be appreciated.
Ollie
Click to expand...


Well, dual 94s will work with a Loadomatic on a stock flathead, in spite of what some state. I ran my '51 with dual 94s/Loadomatic for several years, and could not measure any manifold or distributor port vacuum loss. I eventually installed a Chevy point conversion (staying 6 volts) to prepare for switching to 97s. The stock distributor and vacuum diaphragm have to be in good working order, along with very careful carb matching, rebuilding, adjusting and synchronization.
There is no good reason to run progressive linkage with dual 94s/97s, especially on the Edmunds with it's odd carb spacing. Always run straight.
I started out with an Edmunds intake, so I know it will work OK, but I like the looks of an Edelbrock better, and eventually swapped them out.
 
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I think it would be better for the loadamatic if you ran it progressive.
If you set it so secondary kick in at 50% there would be a fair chance to get the loadamatic working as it should.
Running 2 carbs has to reduce the vacuum responce to the distributor still may work but not as intended from factory.
 
ollie said:
I am thinking of using an Edmunds dual carb intake, progressive linkage, 94 carbs on a 1953 Mercury Flathead.
I
Click to expand...

Do NOT use progressive linkage on this style intake. The runners are too long for good mixing at one end or the other. If you had an open plenum, like a 4bbl intake with a 2x2 adapter, progressive would work very well.

But the 2x2 on straight linkage will work best..especially on an Edmunds.
 
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