I am in the process of converting from fully direct, to progressive linkage on my 250. Does anyone have an pictures of a working progressive setup with three one barrels?

PLEASE HELLLP

Check the directory; "chopped 40" could help you on all that, aka Rap-Rap.

Good luck.

Which direction do your throttle shafts rotate? Parallel or perpendicular to the long axis of the engine? Do you want to use stock linkage or a straight aft pull? I just completed a 5 X 2 progressive linkage on a 261 with five Strombergs, using parts on hand and from Charlie Price's Vintage Speed. My throttle shafts are perpendicular to the long axis of the engine, so that made it fairly easy to adapt a V-8 3 x 1 design. linkage

Have you seen the linkage on the PedalDoctor's nice 292 in this post in Engines?

What he is after is where the other carbs come in after a certin point and Not run all the time.Like
most do when it comes to multi carbs.

Hi,

Instead of trying to "tune" a progressive system to work well, I used the Holley/Weber "Progressive" carbs. These carbs have a progressive linkage built into the carb so you can adjust when the secondaries open. My carbs run on all primaries until I floor it then all the secondaries open. If you want to save gas, you can disconnect the outer secondaries and not starve the outer cylinders!

RapRap
1940 ChoppedChevyCoupe

I'm looking for flat top pistons for my 250 and having a hard time finding them. The block is in really good shape and never bored. Were can I find theses? Lockesblue72

Here are some detailed photos of my Tri-carb linkage set-up. It is very simple and basic and it works great. I am using an Offy 3x1 intake with 2 Barrel adapters and 5200 Holley/Weber Carbs. I am also using a stock V-8 Lokar Throttle cable and bracket hooked to a Lokar Gas pedal. A stock pedal would work too but you would have to attach a mounting bracket so it would activate with the cable. All carbs, manifold, air cleaners, carb adapters and linkage were purchased from Langdon Stovebolt Co. Buying all the parts from one reputable supplier assures you that everything fits and works!


Front of the motor is to the right. This shows the stock straight linkage set-up provided by Langdon.


With center air cleaner removed, you can see how the straight linkage bar and adjustable linkage arm attaches to the throttle cable bracket.


Close-up of the adjustable linkage bar & throttle cable bracket


Where throttle cable from gas pedal attaches to the throttle cable bracket. Make sure there are no tight bends or kinks in the cable.


Top view with air cleaner removed to show the Holley/Weber 2 barrel progessive throats. NOTE: center throttle bar support bearing(bottom of exposed air filter element)

Hope this helps.

RapRap
1940 ChoppedChevyCoupe

Offy makes a progressive linkage setup for the 250 intakes. part number is 5414 and should be included with the intake when buying one new. it is designed to work with a carb that you need to pull down on the linkage, so a set of mid-sixties Monojet carbs would be in order, otherwise you will need to modify carb linkage.