I have been struggling yesterday afternoon and all day today with the stock linkage throttle linkage on the 57 Bird Fordomatic and progressive linkage for the 3x2 carbs. The combined spring resistance of the 3 accel pumps in the carbs is enough to limit the secondaries from opening and full throttle on the primary. There are no return springs on the progressive linkage. When attempting full throttle the spring tension actuates the throttle control rod off its detent at about half throttle and the carb link rod stops moving with the secondaries still closed even though there is pedal travel left. Anyone have some suggestions or illuminations?

57 Black Tbird 312/auto

Somethings back the front, any pics mark.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

The Demon carb I have has a very stiff internal return spring - so it does the same thing. Makes the Ford-O-Matic "overtravel" slot active before the main throttle. So I put a locking stop in the slot - bolt through a thick washer.

But ....then the kickdown lever - at right in the photo - doesn't have enough travel. I've been experimenting with a bolt-on arm extension  to get more downward movement of the operating rod - but no complete answer yet. 

 
 Steve Metzger       Tucson, Arizona

Steve, you pretty well nailed my problem. Your photo shows it perfectly. I was thinking of doing the same bolt down on the slide as you have done. Kind of a half-way fix. I was trying to determine if any trans damage would result having the kickdown restricted. I learned to drive in a 57 Fordo and know how to shift it down to low over 25 or so to get second gear and then shift it back to drive for third. At this point that would be fine. I really need to get my carbs dialed in and if something comes to light later about the kickdown then I will deal with it.



Thanks, getting jammed up with problems like these is frustrating. Annoying time killers. Without this forum I would be up the veritable sh%$ creek without a paddle.

57 Black Tbird 312/auto

Mark - I think the way the kickdown in the fordo works - is that the operating rod is rotating a lever on the tranny that raises the regulated pressure in a "comparator" circuit. When that comparator circuit matches rear pump pressure(?) or something like that - the transmission kicks down. Anyway.......it isn't controlling the band apply pressure - only the comparator. Its not like an AOD or something like that where slippage occurs - it just won't "power" downshift without a comand from the shift lever. 

I tried to send you a PM - but it says your box is full.......

 
 Steve Metzger       Tucson, Arizona

I had the same type of problem with just a stock set up - maybe a worn detent? I put another spring on it (making two) and it works okay, downshift also.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I did put a bolt and nut, washer on the kickdown detent slider. That took care of much of the problem but I spent all day today rearranging the progressive linkage to get the geometry right enough so I can get full throttle with the secondaries open. That meant a lot of trial and error including searching Google Images for Y blocks with 3x2 and progressive linkage. Once that was done it meant more time re-doing the fuel lines to clear the linkage. Tedious stuff. Lots of quality time with a tubing bender, cutter and talking to myself. I did start it but immediately ran into fuel pressure problems. No fuel leaks though. I am using a Spectre low pressure fuel regulator which once out of the packaging revealed it was made in Korea. Doesn't seem to be reliable or working properly. Have to adjust it up to 5PSI to get any fuel to the carbs and it isn't enough. Will start and run now for about 15 to 20 seconds then runs out of fuel. Runs like crap. Missfiring, hard to start, had to prime it several times to get it started the first several times. Worried there was/is contamination or blockage in the regulator. Will get back to it again to tomorrow to figure it out. Local auto parts store owner/old school rat/hot rodder with a 30 Coupe with 4 Strombergs on a Flathead uses a low pressure electric fuel pump that has a 1 to 4 PSI range. Doesn't use a regulator.

57 Black Tbird 312/auto

My personal 2 cents - get a good mechanical pump and stick with that. The FE engine pumps fit and work well (assuming you don't want a vacuum assist unit) so one off a late sixties 428 police interceptor engine will do fine. They are virtually identical to the Holley 80 GPH mechanical pumps (which is graphed below) that are still available too.

 

The number to know is 30 GHP -at pressure - will feed 300HP (the police engines were 335 HP rated).

The line to the carbs can be 5/16 (at pressure) - think of how small the needle/seat orfice is - but the suction line back to the tank would work better at 3/8.

 
 Steve Metzger       Tucson, Arizona

Steve,



The TBird mechanical pump was/is working fine before the intake/carb change. I checked the flow on the inlet side of the pressure regulator yesterday. I will stick with it until I find what the problem is. Going to start by checking fuel bowl on the center carb, disconnect the secondary linkage to make sure they are not opening prematurely. They have no idle circuits. I didn't modify the center carb per Ted's instructions. I put a power valve block off on the spark delay port an block the upper port to the distributor on it as well. I hooked manifold vacuum to the distributor. I also need to check the fuel filter.

57 Black Tbird 312/auto

Update. Found the major problem which was a clogged fuel filter. Simple things can lay a person away. Also found the secondaries not closing completely. Readjusted and added a light weight return spring. Replaced the power valve block off on the spark delay just because. Still won't run below the 5psi setting on the Spectre fuel regulator but it runs and isn't flooding the carbs. Tire shop here found some Michelin Pilot Exaltos and had them shipped in so new American Torque Thrusts will get mounted maybe this weekend. Oh yes....while I was running the engine topping the coolant and adjusting the carbs, a header pipe burned through the rubber brake line running from the Midland power booster to the brakes. Tomorrow I turn the age to officially qualify for Medicaire so taking the rest of the day and weekend off from this project.

57 Black Tbird 312/auto