1953 Mercury Distributor - dual point / single point

[FlatheadFord]

Hello. My dad owns a 1953 Mercury. The car has a Dual Point Distributor. Could a single point Distributor be used in place of it and What is the difference ? Also, can this distributor be sent out and rebuilt - is there a good company that could do that ? I am near Philadelphia, PA.

 

[tubman]

The first thing you need to determine is whether the engine has stock carburetion or not. A stock 8BA type distributor is about the only single point unit that will fit the engine, but will only work with the proper stock carburetor. Ford used a specialized system called "Load-a-matic" to control the spark advance in the distributors during this era. The system used "venturi vacuum" that is supplied from a special port in the carburetor that is present only on carburetors specifically designed for it.

Why do you want to change the distributor? Properly set up, the aftermarket distributors (usually Mallory) work fine. If the carburetion has been changed, they are a necessity to get the car to perform right because of incompatibility with the stock distributor. If the car has a stock carburetor, a properly functioning "Load-a-matic" will work just fine.

 

[mfirth]

Excellent reply tubman. So many want to trash the load-a-matic, which works fine as you said with stock carb. I had a Mallory dual point years ago that i couldn't find points for, don't remember what model it was though.

 

[Ol' Ron]

A single point system works just fine in a stock engine. save your money.
Gramps

 

[tubman]

The problem is, we don't know if it's stock. The fact that it already had a dual point in it opens up the possibility that it may have had other updates. We really need a better idea of what he's running before we can make any recommendations. Ron is right though, about single points being more than enough for a flathead with it's relatively low revs. The fact that he already has a dual point tells me that getting it running right with that distributor might be the cheapest way to go, unless it is worn out.

As to Mike's comment about the non-availability of points, I don't think that's much of a problem. I have found Echlin points from NAPA that cross to Mallory points in two instances, one of them for the flathead Ford Mallory's. When I get the time, I'm going to try to figure out if there are others. Original Mallory points are usually available on eBay if you don't mind paying $25 a set.

 

[19Fordy]

Stock manifold has the port located below the throttle plate for the Load-A-Matic. Stock distributor single pont unit works fine. Dual point is not needed.

 

[tubman]

Stock manifold has the port located below the throttle plate for the Load-A-Matic. Stock distributor single pont unit works fine. Dual point is not needed.

Whoa. That ain't right. The proper place for the vacuum line to the distributor is the port half way up the back of the carburetor. That port is plugged in your picture. Below the throttle plates is manifold vacuum that will not work properly.

 

[flathead4rd]

Right you are Tubman.

 

[40 Deluxe]

Seems like there were kits back in the day to convert stock distributors to dual points. The comparatively weak coils of the day benefited from the extra dwell time in theory, but who really revved their street engine high enough to gain this benefit??
Maybe FlatheadFord has this setup? Need a picture!

 

[19Fordy]

Thank you Tubman for correcting me and providing the correct info.
Glad you did. Jim

 

[paul2748]

Didn't the 53 Merc's use the backdraft carb?

Stock manifold has the port located below the throttle plate for the Load-A-Matic. Stock distributor single pont unit works fine. Dual point is not needed.

 

[tubman]

I have spoken to the owner of the car in question, and the engine has aftermarket heads and a 4 BBL carburetor, which explains the presence of the after market dual point distributor. I will be assisting them and their mechanic on this.

 

[Ol' Ron]

The stock distributor will not work with a 4bl carb under any conditions.
Gramps

 

[scicala]

Didn't the 53 Merc's use the backdraft carb?

The back draft carb you refer too is actually a two barrel teapot style carb with a lid on it (Model 885FF). It was used from '49 thru '51 on Merc 255's. The '52 and '53 Merc 255's used a Holley 1901 model (the two barrel teapot without a lid).

Sal