Tri-power on Ebay..progressive linkage set up


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By MarkMontereyBay - 12 Years Ago
I have been looking at this 3x2 setup and a few others to get some ideas for upgrading my linkage on the 57 Tbird. This linkage looks unworkable to me on a Yblock using the stock throttle linkage. Am I missing something?



http://www.ebay.com/itm/TRI-POWER-FORD-Y-BLOCK-272-292-312-EDELBROCK-INTAKE-NO-553-/300736376736?pt=Vintage_Car_Truck_Parts_Accessories&hash=item460548efa0&vxp=mtr#ht_500wt_945



This is his website. Seems to be doing some good work.



http://www.chevytripower.com
By Doug T - 12 Years Ago
It seems to be set up for a '54 to 56 pass car. So the action to the center carb comes from cross link at the back of the manifold which must pull the bottom hole of the pass side lever towards the back of the car.  On the driver's side the lever on the center carb. shaft with the sliding link rotates forward, eventually contacting the stop on the rod to the rear carb. This  pulls the back lever and that rotates both rear and front carb shafts together.  So I think this set up will rotate all three throttle shafts in a progressive fashion.

The front carb is interesting, it seems to have no idle screws or vacuum signal for the dist. With my3/2 setup I kept the front and rear idle screws adjusted out about 1/4 turn so that the air leakage passed the throttle plates had at least some fuel in it. The builder has plugged the vacuum signal port on the center carb.

BTW the levers on the front and back carb must be exactly parallel and positioned properly.  The link between them must be exactly the same effective length as the centerline distance between the carbs. The center lever must be longer than the two end levers and the sliding stop on the link to the rear carb provides the progressive action.  Most of the time you are driving on the center carb and the rear two don't come into it because the stop has not pulled on the sliding link opening the front and back carbs.  Also that set has the acceleration pump links installed on the front and back so there might be too much fuel dumped if it is stomped on.

Don't forget to get the vacuum signal for your distributor from the manifold, those carbs are intended for a Loadomatic dist. 

By MarkMontereyBay - 12 Years Ago
Doug,



Yep, that's what threw me. I have my set working pretty well but still using the funky Speedway linkage. Getting the leverage to open the secondary carbs with the stock throttle linkage and allowing for enough pull-back to close the secondaries on deceleration was a bitch but I got it finally. Eventually, I want to use the Heim joint, threaded rod, etc. arrangement for smoother action and more secure fasteners. The weak "link" in the Tbird is the stock throttle linkage from the gas pedal to the intake manifold. Lots of flex and not very positive action. Worked fine with a single four barrel but overcoming the tension of 3 carbs is tougher. My end carbs have no idle circuits, power valves or choke plates. Still using mechanical advance only advanced initial timing to get full advance. No problems so far.
By lowrider - 12 Years Ago
I'm using that manifold on my 57 Custom 300. Since I'm running a T5 I didnt use the stock 57 linkage and just used the linkage bolted to the firewall with a rod running to the center carb & progressive linkage on the left side (drivers) of the carbs. Also running just mechanical advance but I modified my center carb to run ported vacuum if needed. Took a bit of tweaking but its running good now.