>>An Idiot's Guide To....Multiple Carburation!!! (Weiand WC4D 4x2)<<

Those power valves I believe have to be modified when running progressive linkage. But I could have swore that I read somewhere that 97's also have a vacuum operated PV type mech that opens up but at a much different flow rate so it doesn't effect it all that much.

 

The best thing is to pick up cores for 94's here and there, to get extra parts. Cores are cheap. And if you need something small that you don't want to buy a core for, Vintage Speed sells almost every part of a Holley 94. Never checked 97's, but they probably have parts for those too. Never messed with 97's, though. Couldn't tell ya' anything about what's available. Getting good rebuildable (and complete) carb cores is the key, though.

Good thing TV's come free with games now!

 

(snicker)

 

Oh I have hopefully enough 94's to make 4 work in the garage. I think I have something like 20 (6 of them are on my HEMI intake) 94's out there that are all in pretty good shape. The trick is getting 4 of those to be matching ones I guess right? Vintage speed is bookmarked in case I need them. I'm hoping that they get those damn fuel pressure regulators ready by the time I need it as well!

 

I'll suggest Mcmaster Carr if you're to piece together your own linkage. Look up "rod ends" and you'll be set. Left and right thread in stainless even, if you want to get fancy.

 

The folks that make the new 97's (NOT Speedways) sell every part for one as well, and every part for the new ones is interchangable with an orriginal. Very nice quality

 

Kingpin

 

Dude, I have a ton of 94 cores, so if you need help making a matching set gimme a yell.

 

He got "Muncied" right into that "incident"!

 

If you look @ the pic, they do interconnect, but not in a meaningfull way. Same as on thier 4X2 inline hemi intake, nonprogressive is the way to go.

 

They do have vac power valves. They need to be converted to "dump" carbs when used with PROGRESSIVE setups, and usually the idle circuits are not used. Also true is an issue with lack of vacuum. Your setup with the cam won't be an issue. Now if you had chosen a duntov 30-30 cam. We would need to talk a little more. You would still run the straight setup, but the power valves would need some attention.


JJ, you are gonna have so much fun playing with this. I'm jealous..a little

 

I hope so Jaws! I'm thinking straight linkage as of right now but I would like a few people with this particular intake to step up and add to the thread before making my final decision. I hope the 94's are going to run well together with my engine.

I'm going to add this part of the thread again to see what people like in terms of Linkage arms.

1.


2.


3.


4.


5.
​

 

The ball end linkages (3) are the best, but I've seen plenty of great intake linkages done with the simple set-screw barrels (2). You're just opening ****erflies on the carbs, not steering a car. But the ball-ends (3) tend to be smooth operating and allow for any mis-alignment in your linkage, should you have an arm that may not be in-line. Some people will also say the ball-ends are "not traditional", but if you look back at early EELCO catalogs they were available just about from the beginning of after-market multi-carb linkages.

The bell crank (5) is used for cross linking between parallel carb rows or changing linkage directions to get to a blower top. They can be used for other purposes as well, though. The same bearings are available through Aircraft Spruce if you don't mind making your own arms. These bearings probably originated in the aircraft market to begin with.

The linkage arm (4) with all the holes are often used in progressive linkage applications but I've also seen them on cross-shafts for the input arm.

Never seen the first arm you've shown (1), but I suspect another progressive type application for the secondary carbs.

 

Your engine will probably flow 1.5 times the air of that flathead as you go over 4000 rpm. You are building a Hotrod right?

 

In the even that 94's are being run in a progressive manner, what is done to the secondary (or "dump" carbs) to eliminate the idle circuit? I ***ume more is involved than simply replacing the PV with a plug, correct?

 

I have his same setup and am going to run 4 97's. If i remember corectly you wont be able to run a progresive linkage due to the fact that the intake runners dont share the same plenum design.

 

I have the same setup with 97's running non progressive linkage. I had a hell of a time getting it too idle. The problem was the throttle shaft extension were not staying in a true line as they projected towards the carbs on the driver side. My solution, was to create a plate that goes across the driver side carbs with a hole drilled centered on each throttle shaft (extended and not extended).

This kept all the throttle shafts on the same plane as the linkage. Thus, curing the problem of binding.

I have some NEW (still in package) Eelco linkage for this setup that I will sell for $85.00 plus shipping.

I'll take some pictures of my current linkage setup. These are old when I had the binding problem.

 

Finding someone running this intake with 94's is going to be difficult I bet. 61cad, I have those pics saved on my computer. Even though I may not go 97's it's still very much a nice setup that I strive for. You've definitely got some cool ****!!!

Let me ask you what engine that running on? 265/283/327/350? Is it a pretty hot motor?

 

1966 Stock Corvette 327-350 HP. Not really a "hot motor". Stock heads and cam (and yes it really is a 66 vette motor, the block has not been decked).

I had a bunch of trouble with the extended throttle shafts. I asked around to everyone I could find about this intake and they all said to run a plate thourgh the throttle shafts to keep them aligned. It was like night and day after I added the plate.

Jay

 

I'd say that's a pretty hot engine....350hp!

 

Here ya go holmes.....

My set-up...progressive '97's. Linkage from Eelco (swapmeet)
http://www.jalopyjournal.com/forum/showthread.php?t=217308

You need to have your fuel pressure set under 3 psi. and the most common Holley regs will not adjust down that far, but they do make one that's 0-4 psi.

 

Those pics you posted are fantastic! Thanks for posting them!

 

I have seen the idle screws turned all the way in on some and others have plugged p***ages and modified bases.

The most recent setup that I was doing didn't use the 94's or 97'. It was a tri carb 348 using carters.

The outside "dump" carbs were period correct and set up correctly for the sixpack. The outside carbs had no idle circuitry at all. Bases were just blades, the carbs were gutted of the power valve also. Meaning only when throttled fully would they pull fuel through the jets, although they did have accelerator pumps for the "hit".

The problem was the engine builder put waaaaaay too big a cam in the 348. .010" less than the 425 horse 409 cam on the exhaust side profile. It had just as much duration too boot, with even more valve overlap than the big motors cam. Translation, 7" of vacuum. Not enough of a signal for low rpm or idle. Really hard to start also. The linkage was progressive, so the little center carb had to do all the work of covering the intake track area with little vacuum.

The solution was to change the bases out on the "dump" carbs so they had idle circuits again. Then with the low vacuum signal, fuel was close enough to the cylinders, so it could maintain and idle and start.

GM new this was a problem, in fact they even had custom cams ground for the 3 deuce carbs motors and vacuum canisters were also installed on the drivers inner fender for the accessories.

Sorry to ramble on.

 

Wow! HAHA! Thanks!

Sorry if I'm going off on a tangent from JJ's thread, but have been trying to think of a way to block idle ports without it being permanent. I have a carb arrangement that I'm setting up as progressive first, but may end up going to a straight linkage later, depending on what I do with the motor. Heard JB Weld will do the trick. I suppose that wouldn't be bad to drill that out of the ports, if needed.

 

Not to steal the thread, but my question seems in the spirit of this thread...

Is THREE 94's gonna be enough to satisify a mild 350 SBC?

PS
I Too have over 30 old 94 cores, so if some swapping is needed to make sets, count me in.

 

I'd think so. The Rochesters have a bit more CFM's which is what was used on GM tri powers but a ton of people run 94's on 3x2 SBC intakes and they run great!

 

Here are just some samples of heims (male) and hex tube drilled and tapped for linkage..
Remember, there is a lot of friction when using several carbs, all pivotes are metal to metal. I recomend using heim joints over more pivote joints as in picture 3. You will get a much smoother feel. Left and right threads on the heims will give you adjustment for throttle plates to open and close correctly.
There is a picture of what the heims and tube looks like. There is also a picture of Eelcos heim joints, the center falls out, poor..
Duane..

 

OOPS, forgot the pictues..
Linkage is inexpensive to build just lots of labor..
Duane..

 

Thanks Strombergs97! That linkage looks great. I'd like to go with the smoothest operator that I can because with me being an amateur/novice car guy I don't need to invite more issues then I already have.

 

JJ, let's clear up some of this mystery about the Weiand WC4D 4x2 intake. Yes, you can use it with progressive linkage. Yes, it does have an open plenum area from the front to the rear carbie. I have built dozens with every kind of carbie. The Offenhauser iss the one you Can't run progressively without leaning out some cylinders. There are a few things needed to be successful such as Sintercustom Josh has found out, you DO need a support plate or other type of support for the 2 inboard carbies for 2 reasons, 1) so you don't put unreasonable pressure on the shafts, and 2) so you don't get irratic running because of the shafts flexing. Linkage is a breeze to make and actually the carbies are easy to set up as true drone secondaries, just like GM intended them to be. Also, the 94's for your little 265 will be just fine, especially running progressively as you are talking about less than 350 CFM for general running and the second 350 not coming in until you reach 60% throttle. The secret to multi carbies is not to OVER THINK the whole thing.