Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 02-15-2013, 03:59 PM   #1
BUBBAS IGNITION
Senior Member
 
BUBBAS IGNITION's Avatar
 
Join Date: May 2010
Location: SPEEDWAY INDIANA
Posts: 3,825
Default 1949-1953 Loadamatic Distributor

We dont do a lot of stock loadamatics but for some reason i have done three this week for flathead customers etc. After shipping over 750 of our Chevrolet mechanical advance units i guess we become pretty one sided?
But i feel as if this orginal vacuum only unit is still very much understood so heres some verbage for discussion and a few pictures of the rebuild done this morning......

Motors manual calls this unit a " Holley Full Vacuum type " unit as it only has vacuum advance with No centrifical advance at all .
This vacuum advance is regulated entirely by the vacuum differential at the carburetor. Some call this venturi as the vacuum is developed when the throttle is opened and air flows thru the carb venturis. At idle this signal would be zero and wide open throttle it may reach 3-4 inches of vacuum ( pretty low strength signal).
The actual specs for the unit is 1 degree of engine timing at .30 ( 1/3 or one inch ) of vacuum and 22 degrees of engine timing at 3.7-4 inches of vacuum.
The slightest variation of the throttle plate will cause this signal to change quite a bit. Even a idle set screw adjustment will change the advance rates for the vacuum diaphram. Ford used this type unit from 1949 untill sometime in the 60s with great sucess as long as the engine was in good shape and properly adjusted..
Tear down is pretty easy , however the drive gear and spacer is a bear to remove as the roll pins are pressed into place!!!!
Once apart and cleaned inspect all parts and reassemble applying lube to all moving parts. Pay attention to the snap ring holding the breaker plate, the rotor retaining clip and bushing conditions.
The springs used for the calibration are mounted on twin adjustable pins. Adjustment is possible by pumping up the vacuum chamber however its pretty hard to adjust with vacuum settings so low...
Attached Images
File Type: jpg 100_9044.jpg (64.6 KB, 104 views)
File Type: jpg 100_9045.jpg (52.8 KB, 87 views)
File Type: jpg 100_9046.jpg (53.4 KB, 81 views)
File Type: jpg 100_9048.jpg (37.9 KB, 84 views)
File Type: jpg 100_9047.jpg (44.7 KB, 84 views)
File Type: jpg 100_9049.jpg (61.6 KB, 79 views)
File Type: jpg 100_9050.jpg (40.7 KB, 78 views)
File Type: jpg 100_9051.jpg (62.2 KB, 94 views)
File Type: jpg 100_9052.jpg (33.2 KB, 95 views)
File Type: jpg 100_9053.jpg (64.6 KB, 96 views)
__________________
If it Makes Spark, we do it !!!!
www.bubbasignition.com
jimlinder@juno.com
BUBBAS IGNITION is offline   Reply With Quote
Old 02-15-2013, 05:45 PM   #2
36tbird
Senior Member
 
Join Date: May 2010
Location: nw SanAntonio, TX
Posts: 940
Default Re: 1949-1953 Loadamatic Distributor

Bubba, can you please show a picture of the trash receptacle that these should go into?
36tbird is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 02-15-2013, 06:16 PM   #3
BUBBAS IGNITION
Senior Member
 
BUBBAS IGNITION's Avatar
 
Join Date: May 2010
Location: SPEEDWAY INDIANA
Posts: 3,825
Default Re: 1949-1953 Loadamatic Distributor

Quote:
Originally Posted by 36tbird View Post
Bubba, can you please show a picture of the trash receptacle that these should go into?
That's good, really good!
__________________
If it Makes Spark, we do it !!!!
www.bubbasignition.com
jimlinder@juno.com
BUBBAS IGNITION is offline   Reply With Quote
Old 02-15-2013, 08:21 PM   #4
bk53
Senior Member
 
Join Date: Mar 2012
Location: Near Dallas
Posts: 387
Default Re: 1949-1953 Loadamatic Distributor

thanks Bubba, always enjoy reading your posts.

Bill
bk53 is offline   Reply With Quote
Old 02-15-2013, 08:29 PM   #5
1937pickup
Senior Member
 
Join Date: Jul 2012
Posts: 586
Default Re: 1949-1953 Loadamatic Distributor

If they were as bad as everyone says-why would Ford use them for so long?
1937pickup is offline   Reply With Quote
Old 02-15-2013, 08:41 PM   #6
Step-down
Senior Member
 
Step-down's Avatar
 
Join Date: May 2012
Location: Hat City
Posts: 517
Default Re: 1949-1953 Loadamatic Distributor

Bubba always enjoy your post .
__________________
"I can't cry as long as I know the Lord has risen "
Step-down is offline   Reply With Quote
Old 02-15-2013, 08:43 PM   #7
BUBBAS IGNITION
Senior Member
 
BUBBAS IGNITION's Avatar
 
Join Date: May 2010
Location: SPEEDWAY INDIANA
Posts: 3,825
Default Re: 1949-1953 Loadamatic Distributor

Actually they do great job for many,many miles.....as long as the carb and engine is in good shape and properly adjusted....
__________________
If it Makes Spark, we do it !!!!
www.bubbasignition.com
jimlinder@juno.com
BUBBAS IGNITION is offline   Reply With Quote
Old 02-15-2013, 08:49 PM   #8
Straightpipes
Senior Member
 
Straightpipes's Avatar
 
Join Date: May 2010
Location: Ballston Spa, NY
Posts: 739
Default Re: 1949-1953 Loadamatic Distributor

Thanks Bubba, rarely does anybody take the time to explain these distributors. You truely do work on anything that makes a spark. I am running two flatheads. One with your Chebbie conversion and another with a mallory dual point that you reworked.
Quite a few guys attempt to run the stock distributor with dual carbs. I think that it is pretty much imposible. What are the thoughts on vacuum distributors with multiple carburators?
Straightpipes is offline   Reply With Quote
Old 02-16-2013, 12:04 AM   #9
49r
Senior Member
 
Join Date: Jul 2011
Location: Wellington New Zealand
Posts: 303
Default Re: 1949-1953 Loadamatic Distributor

I've never had any problem with them. Currently trying a Mallory dual point with 6 volt just to see what it would be like, but haven't noticed any improvement in performance or economy. It's centrifuagal advance only. Will put the Loadamatic back at some point - I like the original look.
49r is offline   Reply With Quote
Old 02-16-2013, 09:08 AM   #10
Frank Miller
Senior Member
 
Frank Miller's Avatar
 
Join Date: May 2010
Location: Auburn, MA
Posts: 1,654
Default Re: 1949-1953 Loadamatic Distributor

I went to a chevy conversion on my stock 49. Have not had a chance to really try it out. I am running the vacuum advance as well. As I understand it it will retard the timing a few degrees when stepping on the accelerator to prevent pinging allowing a little more advance at cruising speeds. Similar to how your wipers stop working when you stomp on it. What I do end up with is a little more advance at idle.
Bubba, What is the total advance of the chevy distributor and how much is centrifugal and how much is vacuum?
__________________
“The technique of infamy is to start two lies at once and get people arguing heatedly over which is true.” ~ Ezra Pound
Frank Miller is offline   Reply With Quote
Old 02-16-2013, 10:33 AM   #11
BUBBAS IGNITION
Senior Member
 
BUBBAS IGNITION's Avatar
 
Join Date: May 2010
Location: SPEEDWAY INDIANA
Posts: 3,825
Default Re: 1949-1953 Loadamatic Distributor

Quote:
Originally Posted by Straightpipes View Post
Thanks Bubba, rarely does anybody take the time to explain these distributors. You truely do work on anything that makes a spark. I am running two flatheads. One with your Chebbie conversion and another with a mallory dual point that you reworked.
Quite a few guys attempt to run the stock distributor with dual carbs. I think that it is pretty much imposible. What are the thoughts on vacuum distributors with multiple carburators?
Once you change the carbs the loadamatic is pretty much history. Maybe not impossible but pretty hard to even start to get it set up correct.
__________________
If it Makes Spark, we do it !!!!
www.bubbasignition.com
jimlinder@juno.com
BUBBAS IGNITION is offline   Reply With Quote
Old 02-16-2013, 10:38 AM   #12
BUBBAS IGNITION
Senior Member
 
BUBBAS IGNITION's Avatar
 
Join Date: May 2010
Location: SPEEDWAY INDIANA
Posts: 3,825
Default Re: 1949-1953 Loadamatic Distributor

Quote:
Originally Posted by Frank Miller View Post
I went to a chevy conversion on my stock 49. Have not had a chance to really try it out. I am running the vacuum advance as well. As I understand it it will retard the timing a few degrees when stepping on the accelerator to prevent pinging allowing a little more advance at cruising speeds. Similar to how your wipers stop working when you stomp on it. What I do end up with is a little more advance at idle.
Bubba, What is the total advance of the chevy distributor and how much is centrifugal and how much is vacuum?
Centrifugal is 16 to 24 degrees and vacuum is 14 degrees on a stock setup. May vary a little.
The issue is that the vac and centrifugal overlap each other as you couldn't have full vacuum at wot or full centrifugal at idle. So combined they would provide a constant 15-24 degrees all the time after the engine was started.
__________________
If it Makes Spark, we do it !!!!
www.bubbasignition.com
jimlinder@juno.com
BUBBAS IGNITION is offline   Reply With Quote
Old 02-16-2013, 03:06 PM   #13
JT FORD
Senior Member
 
JT FORD's Avatar
 
Join Date: May 2010
Location: N.W. Iowa
Posts: 265
Default Re: 1949-1953 Loadamatic Distributor

I ran dual carbs with a load a matic for 60,000 miles with no problems. Had a dual point conversion with a Mallory coil and condensor............In l955 no one used anything off a Cheve...........
JT FORD is offline   Reply With Quote
Old 02-16-2013, 03:32 PM   #14
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 10,294
Default Re: 1949-1953 Loadamatic Distributor

I haven't messed with an 8BA carb for many moons but I have worked on several of the Holley 885 carbs for the Mercury cars. In the early 49 units it was set up for the vacuum advance pretty much like the 8BA carbs were. It was designed to give venturi vacuum from a specific port in one of the venturis plus vacuum from a port lower down by the throttle plate. The internal passage would leak some vacuum from the lower port when the throttle was opened condiderably. In mid 1950 they added a nylon ball in there to act as a check valve and close tha lower throttle port during high openenings of the throttle in order to make the system function more efficiently for wide open throttle and heavy throttle opening. Since Holley made both the carburetor and the distributor, they had a pretty good deal going with FOMoCo for a long time. It functions pretty well for a stock engine but became less efficient when the horse power ratings started to climb with MEL & FE block engines and the Y-blocks changed over to the small block Fords of the 60s. It just didn't do as well with the OHV engines but for flatheads it was adequate.
rotorwrench is offline   Reply With Quote
Old 02-16-2013, 04:01 PM   #15
BUBBAS IGNITION
Senior Member
 
BUBBAS IGNITION's Avatar
 
Join Date: May 2010
Location: SPEEDWAY INDIANA
Posts: 3,825
Default Re: 1949-1953 Loadamatic Distributor

Good addition to the post! Have ya got any pictures of the passages etc to go with this discussion?
Maybe a running engine with a large vacuum gauge hooked to a manifold port and a carb Venturi port . Anyone ?.....?..



Quote:
Originally Posted by rotorwrench View Post
I haven't messed with an 8BA carb for many moons but I have worked on several of the Holley 885 carbs for the Mercury cars. In the early 49 units it was set up for the vacuum advance pretty much like the 8BA carbs were. It was designed to give venturi vacuum from a specific port in one of the venturis plus vacuum from a port lower down by the throttle plate. The internal passage would leak some vacuum from the lower port when the throttle was opened condiderably. In mid 1950 they added a nylon ball in there to act as a check valve and close tha lower throttle port during high openenings of the throttle in order to make the system function more efficiently for wide open throttle and heavy throttle opening. Since Holley made both the carburetor and the distributor, they had a pretty good deal going with FOMoCo for a long time. It functions pretty well for a stock engine but became less efficient when the horse power ratings started to climb with MEL & FE block engines and the Y-blocks changed over to the small block Fords of the 60s. It just didn't do as well with the OHV engines but for flatheads it was adequate.
__________________
If it Makes Spark, we do it !!!!
www.bubbasignition.com
jimlinder@juno.com
BUBBAS IGNITION is offline   Reply With Quote
Old 02-16-2013, 04:23 PM   #16
40 Deluxe
Senior Member
 
Join Date: May 2010
Location: now Kuna, Idaho
Posts: 3,038
Default Re: 1949-1953 Loadamatic Distributor

Motor, Chilton's etc. Manuals of the early and mid-50's had cutaway diagrams of the carb passages that supplied vacuum to the Load-a-Matic distributor. As I remember, it was a mix of ported and venturii vacuum (ported vacuum goes away under heavy load/full throttle so venturii vacuum is needed to maintain the necessary advance). As air rushes through the venturii (which is a smaller diameter than the throttle bore) it causes a low pressure area (or partial vacuum) which allows atmospheric pressure in the float bowl to push the gas through the jets into the airstream. This partial vacuum is used to provide the high speed advance signal. Somewhere after '49 a 'spark valve' was added to the carb to further refine the advance curve. This is the thing that looks like an external power valve, sort of.
Incidentally, venturii vacuum is what Holley uses to open the secondaries on their 4 barrel carbs.
40 Deluxe is online now   Reply With Quote
Old 02-16-2013, 05:56 PM   #17
richard rink
Member
 
richard rink's Avatar
 
Join Date: May 2010
Location: louisville ky
Posts: 90
Default Re: 1949-1953 Loadamatic Distributor

I am running dual 94's on an 8CM, getting a vacuum signal off one of the carbs. I appreciate that the signal is diminished because of the dual set-up. To amplify the effect of the reduced vacuum, I removed the two springs on the breaker plate and installed a single, weaker spring. A small amount of suction causes rotation of the plate. In operation, with a heavy foot on the accelerator, there is sufficient advance to cause "pinging." Acceleration is excellent. This is very much a shade tree kind of approach, but I am satisfied that the set-up works. .
__________________
twodeuces
richard rink is offline   Reply With Quote
Old 02-16-2013, 06:37 PM   #18
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 10,294
Default Re: 1949-1953 Loadamatic Distributor

Quote:
Originally Posted by BUBBAS IGNITION View Post
Good addition to the post! Have ya got any pictures of the passages etc to go with this discussion?
Maybe a running engine with a large vacuum gauge hooked to a manifold port and a carb Venturi port . Anyone ?.....?..

I'll see if this will work. You may have to open it in a new window and resize to read it.

The Lincoln 337 used a different system so the carb was set up differently.
Attached Images
File Type: jpg scan0002.jpg (50.6 KB, 90 views)

Last edited by rotorwrench; 02-16-2013 at 06:49 PM.
rotorwrench is offline   Reply With Quote
Old 02-17-2013, 11:19 AM   #19
BUBBAS IGNITION
Senior Member
 
BUBBAS IGNITION's Avatar
 
Join Date: May 2010
Location: SPEEDWAY INDIANA
Posts: 3,825
Default Re: 1949-1953 Loadamatic Distributor

Quote:
Originally Posted by richard rink View Post
I am running dual 94's on an 8CM, getting a vacuum signal off one of the carbs. I appreciate that the signal is diminished because of the dual set-up. To amplify the effect of the reduced vacuum, I removed the two springs on the breaker plate and installed a single, weaker spring. A small amount of suction causes rotation of the plate. In operation, with a heavy foot on the accelerator, there is sufficient advance to cause "pinging." Acceleration is excellent. This is very much a shade tree kind of approach, but I am satisfied that the set-up works. .
Good thinking Richard, that's what makes it work!
__________________
If it Makes Spark, we do it !!!!
www.bubbasignition.com
jimlinder@juno.com
BUBBAS IGNITION is offline   Reply With Quote
Old 02-17-2013, 11:22 AM   #20
BUBBAS IGNITION
Senior Member
 
BUBBAS IGNITION's Avatar
 
Join Date: May 2010
Location: SPEEDWAY INDIANA
Posts: 3,825
Default Re: 1949-1953 Loadamatic Distributor

Quote:
Originally Posted by rotorwrench View Post
I'll see if this will work. You may have to open it in a new window and resize to read it.

The Lincoln 337 used a different system so the carb was set up differently.
Good pictures of the function and overall importance of the throttle opening and the adjustment required.
You can see that even a mis set idle speed would also effect spark timing....
__________________
If it Makes Spark, we do it !!!!
www.bubbasignition.com
jimlinder@juno.com
BUBBAS IGNITION is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 01:08 AM.