292 y-block distributor puzzler

Ummm, hate to tell you this, but the reason you are experiencing slipping of that linkage is because you are missing a tension spring between the upper and lower sprags of that kickdown element.
The reason they have that slot in there is so you can punch the gas pedal and achieve intermediate gear kickdown without damaging carburetor butterfly valve shaft and associated linkage. That spring takes up the slack, but during normal driving the spring holds that kickdown element steady.
I suggest NOT using your passing gear kickdown until you can replace that missing spring and pull that piece of plastic tubing out of there. Once that spring is put back, you should be good as new.
 
Here is a photo of '55 Ford Y-block with 2-bbl carb passing gear link. Notice the two movable plates with the spring pulling them together. That is the spring you are missing. The slot on mine is hidden on the backside.
 

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I was just about to look in the '56 parts book to check on that area. A missing spring (just broke and fell off most likely) would explain the problem. I put the hose piece there just to test my theory. I've been collecting and working on "older cars" for 40 years and this was one of the harder problems to figure out, even though it's simple in a way.

Bill
 
"And de-acceleration."




The dual diaphragm '56 only momentarily retards the spark in low manifold vacuum when accelerating. Deceleration is high vacuum. The text in the link I posted earlier explains how it all works.


Sal
 
I had a similar problem with my 56 TBird. I put and extra spring on it and it now works fine.


highcking said:
I discovered with the help of my wife that the throttle linkage is slipping at partial throttle. On the linkage to the rear of the carb, there is a hefty pin that goes through a curved slot which I think is the downshift activator at full throttle. My linkage is slipping that pin at partial throttle which means the actual throttle on the carb stops moving entirely. It also explains why pumping works - the pin resets itself and allows more movement of the throttle. What the heck? I haven’t messed with that mechanism at all.
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scicala said:
"And de-acceleration."

The dual diaphragm '56 only momentarily retards the spark in low manifold vacuum when accelerating. Deceleration is high vacuum. The text in the link I posted earlier explains how it all works.

Sal
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I only go by FORD info Sal, not someone's interpretation..
 
I believe that info was from Holley or Ford, and I believe it to be true from my experience. To each his own.


Sal
 
scicala said:
I believe that info was from Holley or Ford, and I believe it to be true from my experience. To each his own.

Sal
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I have no idea. The referring URL you posted expired. You cannot post a SEARCH URL as it will self destruct. Remember MISSION IMPOSSIBLE?
 
I guess I don't know computers that well. When I click on the link it says it's expired, but shows a link to go to it anyway. I've tried it twice and worked both times for me. If you can't see it, maybe just google "1956 Ford dual diaphragm distributor". That's how I found it originally.


Sal
 
probably not helpful to have that hose laying on top of the bellcrank mechanism. I would reroute it. Just to take that out of the equation.

Good luck with the issues, These vac advance deals with the 56 Load a matic are frustrating but can be solved with a lot of patience. And unfortunately some extra money sometimes. Hang in there.
 
The fuel hose is a problem. If you route it under the bellcrank mechanism, it is getting pinched against the intake manifoold. How did the factory do it?
 
highcking said:
The fuel hose is a problem. If you route it under the bellcrank mechanism, it is getting pinched against the intake manifoold. How did the factory do it?
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It is not supposed to be rubber hose at all. It should be metal tubing. Try to duplicate the routing shown in the '56 Ford car shop manual in various places, or you can actually buy that fuel inlet tubing (pre-bent) from various repro parts suppliers. I got all my undercar fuel and brake line tubing from a company called "Inline Tube", but they also carry a complete line of fuel and vacuum tubing for the engines.
The rule of thumb I like is: Use as LITTLE of rubber tubing as possible in fuel and vacuum systems. Rubber breaks down under heat and age and becomes damaged by contaminants in ethanol, so it needs to be checked for cracks periodically. Metal tubing lasts practically forever.
Some of your chain auto-parts stores have been offering copper-alloy tubing for a while now, so if you are creative like me, get some and bend your own for custom fit. And get new brass compression fittings too.
 
highcking said:
A few extra data points on my Loadomatic system. Timing results:

No vacuum lines connected: 6 degrees BTDC
All vac lines connected: retarded into ATDC range
Ported vacuum only: same, retarded into ATDC range
Manifold vacuum only: 6 degrees BTDC

The problem I am trying to solve is a strange form of poor performance. Engine starts instantly, never misses, backfires, etc. and idles smooth. Problems? Hesitates on sudden acceleration, though I can see the accel pump jets squirting. Weirder problem is that engine rpms do not come up with pressing down the accelerator pedal slowly. (Linkage is free and moves fine by hand.) You can get all the way to the floor and be going 35 mph. If you pump the pedal, you can get the car moving to higher speeds. Without pumping, you’re dying on a hill. With a 200 hp Y-block!

Holley 4000 is a Suter rebuild from a few years back. Electric choke works fine, choke plates open when warmed up. I have another rebuild I can slap on if need be. I just can’t figure how the engine can be turning low rpms (albeit smoothly) with the pedal almost to the floor.

Bill in Luray
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Just wondering ~ has the problem been found with the spark retarding (with vacuum connected ) at idle??
 
Stiggy - no. None of the reference manuals say anything about the correct vacuum readings except the reading of 6 degrees BTDC with vacuum advance shut off. But the ATDC reading may be correct anyway. In a regular system, when you check timing at idle, there may still be a small advance contributed by the centrifugal advance weights in the distributor. I’m not sure about that. There’s no obvious way to check timing under true load conditions Where manifold and ported vacuum change as soon as the engine is put under load. I’d like for others to report their vacuum reading at idle with the vacuum lines connected. I still could have a faulty unit though it seems to work ok.
 
highcking said:
None of the reference manuals say anything about the correct vacuum readings except the reading of 6 degrees BTDC with vacuum advance shut off.
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Look in your SHOP MANUAL under SPECIFICATIONS and you should find the advance specs there.
 
It shows the base reading of 6 degrees BTDC for no vacuum to the advance unit. I can’t find a reference anywhere on readings for other conditions. This was a one or two year item that depended on the teapot with the spark control valve. In 1957 the whole system was dropped.
 
highcking said:
It shows the base reading of 6 degrees BTDC for no vacuum to the advance unit. I can’t find a reference anywhere on readings for other conditions. This was a one or two year item that depended on the teapot with the spark control valve. In 1957 the whole system was dropped.
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I am trying to figure this out- (but I am old) ...

You went to the SPECIFICATIONS SECTION of the FORD 1956 SHOP MANUAL and under IGNITION did not find the curving and vacuum values?

I understand the LOAD-O-MATIC SYSTEM, so no need to post the description.

BTW - LOAD-O-MATIC was used on six cylinders until the 1968 model run.
 
Even if you have the specs on how much vacuum to the distributor inner diaphragm, and how much spark advance that vacuum level represents, I don't think you will be able to check it with a timing light unless you have the engine on a dyno, or the car on a chassis dyno since all the specs are based on light to heavy loads on the engine and not racing the engine in neutral. I can tell you based on my Holley carb manual that the most vacuum you will see is about 4" hg. And that is at high RPM and basicly wide open throttle. At that point the vacuum signal is mostly from venturi vacuum (suction)and not manifold vacuum. Manifold vacuum at wide open throttle will be no more than 2" hg at high RPM.


Sal
 
Not to over-ride you Sal, but actually the values in the SHOP MANUAL are intended to be used on a DIST ANALYZER.

The complete system (DIST and CARB) is so complex, I don't see how anyone (without wild guessing) could calibrate one on the car as you can a DUAL ADVANCE. You might get it somewhere operational but not to spec.

The ONLY USE I can see to use the LOM if the car is a dedicated restoration. Even then (if a driver) I would have the two systems on hand if I wanted to drive it.

But the values are in the MANUAL.


407481
 
I agree that loadomatics are probably all over the place as far as two working the same.


The specs I have are from Holley for their distributor, but they give the specs for the '56 Teapot carb vacuum, and are all based on distributor RPM versus engine load (manifold vacuum).


If it were my car, I would probably have an aftermarket or '57/later Ford distributor on it.


Sal
 
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