Hey all,
I know this will sound a lot like other questions, sorry. Just converted my old 302 with a 2 bbl Motorcraft (bad internals, had to be rebuilt or replaced) to a 4 bbl Holley. I must say it is a sweet carb, and even got me through emmisions, something the old motorcraft couldn't. Well now I have a problem, the kickdown linkage doesnt quite line up perfectly. I did adjust it at the bottom, and it will stay on the position which it should, but when it kicks down, it stays down. Is this right? I don't want to be going like 75 mph in passing gear.

Also, I used a 4bbl to 2 bbl intake conversion plate, due to a lack of money to get the 4 bbl intake. How much different would a 4 bbl intake be, considering the vehicle is 6300 pounds, and chugs gas.

Thanks everyone,

Carlo

 

You would have a much better top end with the 4BBL intake. Check out the classifieds here, or try scouting the junkyards in your area- it's amazing what people will just throw away.
As far as the linkage, without actually seeing it do this, the best guess I can give is that the adaptor is making the carb sit to high, and the linkage is binding.

 

I have not tried this before, but I have heard that the kickdown linkage from Fairlane models with a 302 adapt real well to modified/swapped Ford truck engines (small block) with 4bbl's. Might be worth a trip to a junkyard?

 

Should the kickdown linkage spring back up by the power of the transmission? Because I should be fine then, beings hieghtwise it hasnt changed much, (Vacuum Governor removed as well as large Carb Spacer).

I'm gonna go play with it a bit, and if you guys think a 4 bbl intake would be worth my money, I may do it, but right now, money=limited.

Thanks guys.

 

OK now let me get this straight. Are you saying that your kickdown is sticking, and you don't have a kickdown return spring but are relying on the throttle return spring? The "nexus" between throttle return and kickdown is usually linked, but not exactly "together" or "in sync." If you have a kickdown linkage, you should have a return spring independent of the throttle return spring...meaning, you should have two return springs: throttle return, and kickdown return. At least it is designed that way on Autolite and Holley 2bbl's for Ford V-8's. I always make it my practice to have return springs on both. BTW, I believe a kickdown return spring will also act as a throttle return spring, but not the other way around.

PS-The kickdown should return the weight of the linkage on its own when you move it back and forth, but it won't have the return ability you get with a separate spring and bracket on the carb and manifold.

 

I recently replaced my factory Motorcraft/Holley with a Quadrajet, Yeah, yeah, I hear you all, but I still think it's the finest street carb ever devised. Anyway, the factory Holley 4180 had a separate return spring for the kickdown, running between the two pieces of the throttle linkage. I had to study this thing for a bit to figure out how to make the Q-jet work. What I came up with wasn't elegant, but works. I did manage to measure some inportant things though. At closed throttle(idle), the kickdown rod end was almost lined up with the ball for the throttle cable, resting only 1/4" behind it. The throttle cable moved a total of 1-1/2" linear movement from idle to WOT. The kickdown began to move at 2/3 throttle, and moved a total of 1" linear travel. The return spring was very light, and very small, but any universal throttle return spring from the parts house should work fine, although on mine, even with the adaptor plate, the kickdown returns to NEARLY it's proper resting position with no spring at all.
BTW, when it kicks down and the Q-jet secondaries snap open on the 351, otherwise all original, have it pointed where you want to go!

 

Check out ebay for a goo used intake, but look for a dual plane intake and not a single plane, and you should pick up a lot crisper throtle responce and more low end tork which will help in something that heavy. DW

 

you can bed the tubing to make it fit better, I have done this numerous times. Chuck the adapter and get either a stock 4bbl intake or something like an Edelbrock performer dual plane manifold.
To compair the manifold to the spacer, try pouring a quart of oil into a funnel, see how it slows way down at the small end of the funnel? This what the spacer does to the air-fuel mixture.
There should also be a spring that attatches to the kickdown linkage on the carb to the carb itself to make sure that it returns. I would look for one in the bag of parts that came with the carb. Also, read the directions that came with the carb, it will help you figure out the linkage.
Jimmy