Big Block Weber Linkage
 

I am working on a Weber setup for my FE and curious about the linkage. I have the linkage components as supplied by Pierce Manifolds. It is a center bellcrank on a stand with individual arms to each side, pushing on the carb lever arm. Both sides are adjustable so as to set idle. I've attached a picture of it.

Looking at some of the other setups and Jim Inglese' site, I am seeing the bellcrank only connecting to one side then a cross bar connecting from one carb bank to the other - ala small block style.

Looking at Comp's catalog and the eBay stores, I see they are selling big block linkage that again uses individual arm connections from the bellcrank to the carbs.

So, doing my research, I don't find many pictures of Big Block Fords with a canted manifold and Webers. To the guys who have them, how about a few pictures?

I did find a thread condemning the crossbar style linkage, saying it would not correctly sync one side to the other. Not sure I buy this 100% unless the user's linkage didn't have his geometry correct.

How about pictures of comments on the best linkage setup for a canted big block

Thanks

Paul

Hey Paul,

Sorry I don't have any of the pictures you seek, but if I were seeking info on linkages and sinking TB, I can strongly recommend EFI Hardware.

Here's a quick link to their "linkages" page.
Linkages

I have first hand knowledge that they have fixed inherent mechanical problems in other supposedly "reputable" systems (both weber and EFI 8 stack).

I have a Jim inglese supplied system with the crossbar type linkage It's on 289, not a big block, but for the sake of this discussion, that is not relevant. It absolutely opens each back of carb equally from idle to WOT. Don't see how others are having so many issues with this.

Now maybe in theory, there is some minor variation from side to side, I don't know. But in actual practice, with quality dial gauges positioned on opposing carbs, there is zero MEASURABLE difference from bank to bank with the crossbar linkage. At least with the one that Jim I. sold me. Now I can imagine that someone could try to cobble together a similar linkage, and get in ALL wrong if they didn't know what they were doing.

Z.

Paul I would try putting the connecting links on top of the Bellcrank, and swap the throttle shaft links to make it into a Pull type setup. If it is possible, may have to swap carb lever pieces to the opposite bank??

Linkage
 

With Pierces linkage on a FE you can reverse the male and female pcs but the lever only works on the bottom.
Jon

Yup
 

The setup is compounded by the 10degree canted mount. The levers won't clear the manifold bolts so they have to go on top. I wasn't real wild about the linkage in a "push" style but when I got all done, it is very smooth with no glitches.

I really feel sorry for the guy who put 48's on a canted manifold FE for the first time. I can't imagine doing it without the internet. :eek:

Paul

Actually the fact that the carbs are canted at an angle does not really matter as far as the linkage goes, the linkage just needs to make the movement from idle to full throttle. Here is the linkage I fabricated starting with the same parts you used.

Hi Paul
Pictures of my solution:

I've used both style of linkage, and I think they work the same with most manifolds. But not on a manifold where the carbs/TB's are canted. At an angle like that, the end of the rod will not move in a straight line, but in an arc. If you're using a linkage like in your picture, that will be OK because, they'll move in the same arc on both sides. If you have a cross bar, it will move in a straight line, and therefore open at a different rate from one side to the other. It will balance at idle, but the more you open the throttle, the more imbalanced it will become.

CompCalassics and Walter, those hoses have far too much bend in them. They will break down and fail on the inside. That will block fuel flow from one side to the other.

Walter, you would probably do better to eliminate that long cross bar, and connect it to the bell crank. If you measure it, I bet you'll find that they out board ends of the bars do not move in the same arc. It's hard to tell from the picture, so I could be wrong. But I would measure them to be sure.

When I first installed mine, I really struggled with getting everything to move right. In the end, I dumped most of the linkage that came with the kit, and built my own. I paid very careful attention arcs and throttle blade movement, using a dial indicator and digital calipers to measure linear movement. It was tedious work, with lots of trial and error. Made a huge improvement in performance.

Bob: I agree. I bought my set up used, and it came with a straight cut manifold. I had it milled for 10deg and the linkage no longer worked. Traced it down to the L & R throttle arms were going through different arcs at different times. I made a temporary fix by shortening one throttle arm and it all worked ok, but I plan on going to a center bellcrank when I can find one. System has been replaced with a 4 barrel set-up due to weber manifold sealing problem. (actually a head problem) on one side. Will be pulling engine for that and oil leaks, webers go back on when engine goes back in.

Ted

Hmmm, the carbs are canted on our installation, the linkage setup I fabricated works perfectly. Paying attention to shaft angles really is important to linkage operating performance. One thing that you did not mention that you use is a level, some angles will change with movement but if the initial angles are wrong to begin with you are fighting a losing battle. Quality hardware is also essential.

You two boys would be better off eliminating the bent hoses and fabricating a 180 degree hard line.

Much less chance of failure.

Dig up an old post by RoknDad, who has sadly left us. He posted an entire build thread on how he did his Weber setup on an FE.
A great guy and still missed....

I tried doing a hard line. But I wasn't talented enough to get it right. So I did this instead. It's completely different now, but this worked fine for a few years.

http://i13.photobucket.com/albums/a2...psa749e08c.jpg

Thank you for the picture.
How would you make the linkage in my case ?

to start with, I would leave the short arm where it's at. I would remove the long arm, shorten it, and attach it to the same place the short arm is.

It still won't be exactly right. because the two arms are different lengths, the arc will be slightly different. But I think the difference would be so subtle you wouldn't notice.

If you want it to be exactly right, make a new pedestal for the bell crank in the exact middle of the manifold base. Then the two arms would be the same length, and move through the same arc.

http://i13.photobucket.com/albums/a2...pshsnlht6u.jpg

The center pivot does provide a better pivot point point for the linkage.

Thank you Bob for the tips and suggestions.
First I want to change the 180 ° fuel line