Mark,



Just going by my own experience. Original Loadomatic with 60K on it, probably only had points service since new (regular bushing lube unlikely), but still running fine. After pro rebuild & setup, got the "500 lbs. removed from the trunk" effect.

Have a spare Loadomatic that I will eventually rebuild also, but WILL invest the setup time to satisfy curiosity before installing a tuned Mallory, for definitive A/B comparison test of both units in max tune.

6 VOLTS/POS. GRD. NW INDIANA

Actually Daniel I have to disagree with part of your statement.I simply switched to the later distributor and noticed a definite improvement in driveability.My loado was not worn out.I did this about 2 months prior to installing a Holley 390 and the "B manifold.Adding the later carb and manifold is the next step to improving the way it runs.Äs far as tuning the distributor that time and money is better spent tuning the later distributor as far as I am concerned.Just my opinion.

  

[quote][b]GREENBIRD56 (9/21/2010) "maintenance difficulties would be high on that list"



Steve,



Was just referring to to the typical comments about improved acceleration after a switch to '57 & up distributor ("like removing 500 lbs. from the trunk"). By the time most get around to that swap, which often includes a carb. upgrade BTW, the Loadomatic is worn out and badly tuned. The same increase in performance can usually be accomplished by rebuilding & speed tuning on a Sun machine! Balancing the Loadomatic springs, and tuning a hot curve IS indeed difficult. That, and the added slower advance (vacuum restriction) was likely reason enough to make it obsolete.

6 VOLTS/POS. GRD. NW INDIANA

Actually as I recall they used the loadomatics on the 144-250 6 cylinders through the 60's.Stopped using them on the V-8 after 56.

  

Steve; Re the Load -O-Matic distributors, a small correction, they were abandoned "after" 1956.

Paul

Daniel - Isn't the dual diaphragm "Load-O-Matic"  the one we were discussing? By mechanical means the two canisters are tied together and in a manner of speaking "summed". One of the two vacuum cans is hooked to manifold vacuum and I believe it then provides "auto retard" by dropping out when the throttle opens. The other can runs off the venturi effect at the throat - measuring air speed into the intake.

The Load-O-matic distributor technology (purely vacuum based) was abandoned by Ford in 1956 - probably for good reasons ..... maintenance difficulties would be high on that list I'd imagine. It can be made to work (run an engine) - it just has some problems.

 
 Steve Metzger       Tucson, Arizona

[quote][b]GREENBIRD56 (9/21/2010

"the torque advantage of the mechanical advance version at lower levels of rpm is hard to overlook".



Steve,



While I agree the later mechanical advance distributors deliver superior performance (quicker advance/not slowed by restrictive vacuum passages), I still wonder whether the Loadomatic's higher allowable initial advance setting (no throttle activated retard with centrifugal) might cancel much of that advantage if tuning was truly maximized?




6 VOLTS/POS. GRD. NW INDIANA

Don't avoid the use of the later mechanical advance style distributor on account of a lack of a "ported" vacuum source on the carb - it can and will work just fine. Tuning is slightly different with the live manifold vacuum at idle (versus the ported) but the system will behave just fine on the road. When the throttle opens, the behavioral differences mostly disappear.......but the torque advantage of the mechanical advance version at lower levels of rpm is hard to overlook.

There are some articles (provided by our Mustang enthusiast brethren) that show the differences and similarities of the Autolite and Motorcraft versions of the Ford distributor - but not really much is found about the earlier "Load-O-Matic". You could re-bush it if parts are available and get everything back to original - it will just take a bit of effort.

http://www.mustangmonthly.com/techarticles/mump_0904_how_to_rebuild__autolite_motorcraft_distributors/index.html

http://www.mustangmonthly.com/techarticles/mump_0702_ford_mustang_distributor_rebuild/photo_17.html

 
 Steve Metzger       Tucson, Arizona

Your right! The original Carter thats on the engine has a vacuum port in the front that has a spark control valve that goes to the primary vacuum diaphragm on the distributor. At the rear of the Carter has a manifold vacuum source with a brass block that has two ports. One port goes to the secondary vacuum diaphragm on the distributor while the other goes to one of the vacuum assist on the fuel pump. Thanks for all the input - AR

You cant use the one that worked with the stock distributor because its controlled by a  "spark advance " valve in the carb.