Vacuum Signal


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By Rono - 5 Years Ago
I'm planning on changing out the valley pan on our 56 Ranch Wagon and eliminating the road draft tube. The car runs GREAT with the original Load-a-Matic and modern Edelbrock 500 cfm carb. I hate to pull the distributor when it's running so well. The PCV port on that carb has been capped, but if I run the PCV line from the valley pan PCV valve to the port on the carb will it interfere with the vacuum advance signal to the distributor?  I am running electric wipers and a more modern fuel pump so no vacuum needs there.
By miker - 5 Years Ago
If your going to use the PCV port on the front center of the carb, and either the full or ported vacuum port to either side of it, it’s never been a problem for me. The key is the right PCV valve that does create a huge vacuum leak. Charlie has an adjustable one, and I think Steve Metzer uses a drilled orifice. I’ve never had a problem with one for a similar size engine.

You may have to do a little idle screw adjustment.
By charliemccraney - 5 Years Ago
If you use the correct ports, it will not interfere.  There is a PCV port and there are manifold and ported ports for the ignition.

However, it's not running great with the mismatch.  If you think it is currently great, put the correct distributor in and be amazed.  Timing is totally incorrect right now with the mismatch.  I'm wondering if you're kidding because I'm surprised that someone who is fairly regular here would do that.
By miker - 5 Years Ago
Oops, I missed the loado comment. Charlie’s right. 57 up distributor works fine with the correct use of the ports.
By Rono - 5 Years Ago
What I can tell you is that I have not touched the dizzy or the carb since we bought the wagon. It fires right up with the Lodomatic and will smoke the tires if you put your foot in it. It doesn't bog or stumble. The way my wife drives (easy-peezy) this works for her. I was always of the opinion; "if it ain't broke don't fix it". We just want to stop the oil puddle on the garage floor from the road draft tube. I have a 57 and later dizzy. When it starts running like crap I'll change it out.

By PF Arcand - 5 Years Ago
Re the oil loss from the Draft tube;  The most likely reason is that the "drain back tube" on the inner side of the unit is plugged. U can unbolt it from the  block to clean the tube, or possibly clean it out with a flexible wire inserted in there, but that is very difficult to do.  Also check the gasket to block & the condition of the draft assembly.  Another contributing factor could be that the oil filler cap / breather is completely plugged up & there's also a removable filter screen in the draft unit also. Those items have been an ignored service problem for years, contributing to sludge buildup in the engines...      
By Florida_Phil - 5 Years Ago
If you have an unmodified Loadomatic distributor running with a modern Edelbrock carb in your engine, your timing advance is not working correctly.  You may be compensating for this by running more timing on your crank.  I have had many drag cars where we locked the distributor at full advance and they perform well 1/4 mile at a time. This is not something you want on a street car. Doing so could cause detonation and idling problems.  If you are happy with what you have now, I wouldn't change a thing.  If you make changes, you could be opening up a whole new can of worms.   The ultimate fix is to match the distributor and carburetor.  Better yet, replace the Loadamatic.  Some day your mismatch will become a headache.  Just my two cents.
By Rono - 5 Years Ago
Phil;
I agree with everything you are saying. I have no idea whet the previous owner did with respect to the distributor. It does idle fine. I have not checked the timing because I haven't had the need to. Maybe I will wait until the dizzy takes a dump and then change the valley pan and put the later distributor in. I have had the entire road draft tube assembly off the block, cleaned in my parts washer and replaced the filter element. Didn't make any difference with the oil discharge from the tube.
By oldcarmark - 5 Years Ago
I just sold a 1957 Distributor to a Guy who bought a 1956 F100 with 292. Previous Owner installed an Edelbrock  4bbl but left the Loadomatic. Now the Truck runs like it should. I changed another One last Week for another Guy for the same Reason. Beautiful 56 Victoria with 292. He had the Intake and Carb changed to get away from a Firepot that was causing all kinds of Trouble. He's been driving it for over a Year with Loadomatic. He said it ran OK but it would "Surge" at Speed which I guess was the Vacuum coming on and then cutting out when the Accelerator was increaseed.  It took some convincing to get Him to spend the Money but now it runs the way it should. I don't know how the Loadomatic works with later Carb. My understanding is they shouldn't work at all.
By Gene Purser - 5 Years Ago
Two-three years ago I bought a '55 with a 272 that had been changed to a Edlebrock carb and still had the Load O Matic distributor with a pertronix module. It was set on 15 degrees initial and the vacuum advance added another 20 degrees as soon as vacuum hit it. It ran "OK" at lower RPMs but would go "pop-pop-pop" out the exhaust instead of rapping when the RPMs got higher. I immediately bought a '59 distributor for it. Now it runs great and the Smithy mufflers sound like they should.
By Florida_Phil - 5 Years Ago
When we were kids in the sixties, we would swap out our toilet bowl carbs for Holleys or AFBs. Our motors never ran right.  We always knew V8 engines out of 1957 cars ran great, so we were on the look out for them.  1957 Fords were common. There were always one or two behind someone's house or in a field.  (I grew up in the South).   I remember buying compete running 1957 engines for $50.  You could buy a whole car for $100. 

We never knew why 57 YBlock engines ran so good until much later.  The Loadamatic was one of the reasons the scruby's got the jump on us.  Once Ford fixed that piece of junk, things changed. (Lemans 66-69)
By Stiggy - 5 Years Ago
Rono ~ I had the same problem with oil dripping from the breather. The "O" ring looked fine so to
            did the gasket on the block. I put grease on the block gasket but it still leaked.
            It turned out that someone had put a used gasket on ~ it had a barely noticeable impression
            in it that allowed the oil to leak.  A new gasket fixed the problem..
            Hope this may be of some help..   
By KULTULZ - 5 Years Ago
Rono ~ I had the same problem with oil dripping from the breather. The "O" ring looked fine so to
            did the gasket on the block. I put grease on the block gasket but it still leaked.
            It turned out that someone had put a used gasket on ~ it had a barely noticeable impression
            in it that allowed the oil to leak.  A new gasket fixed the problem..
            Hope this may be of some help..[/quote]

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