Well I have searched several different key words here and have come up with several close examples of what I am looking for, but nothing that really hits the mark. I need some pictures, drawings, ideas for a 4x2 inline carb. linkage set up, with the center two being primaries and running the outer two as progressive secondaries. I have carb risers, so the linkage can go below the throttle bases. I have the Eelco linkage for this, but the long rod that links the two outboards does't come close to reaching...no big deal, just make a longer rod...or am I missing how this linkage kit is supposed to work? Any help, ideas, experience? Here is picture of what I've got...old pic., the carbs are done and I am ready for linkage. http://www.directimagehost.com/is.php?i=151411&img=100_1055.JPG Also any ideas on linking the two primary chokes? Kurt
If a straight linkage would do it, here's one way. Granted, triples, but another rod etc. would pick up another carb. Take a look at Edelbrock's dual quad progressive linkage. It's a nice piece and could be easily expanded to four 2 bbls. Not hard to make your own with the right Heim joints. There is a double sided Heim joint that really makes life easy once you get into triples and beyond. Progressive isn't hard to make either. I'd copy a good commercial design, use good quality Heim joints and thread my own rod etc. As far as hooking up two chokes, you may not need to. Factory installs of dual quads usually have only the rear carb set up with a choke. That said, I hooked up both chokes on my dual quad setup. I may try hooking up only one next time I run this intake, but the dual chokes worked great so I may leave em. Simple enough if the carbs you want to choke have the brackets & clamps. One choke cable is all that's required. Run the cable - using smooth and large radius turns if you can - to the rear carb. Make the short run to the front carb. Once you're happy with the cable layout, mark the outer sheath, remove the inner solid wire cable and cut the outer sheath to length. It should be long enough so it will be set up for operating the rear carb. Clamp the outer sheath in the rear carb bracket. Cut a short piece of outer sheath from the leftover cut off piece. This gets clamped into the front carb bracket making for a guide and brace for the inner wire. If you look close at the 3rd pic you'll see the guide outer sheath on the front carb. Best pic I have right now, seems I never have quite the angle I need. Install the inner wire, when it exits the outer sheath push it through the choke operating arm clamp, leave the clamp loose. Push the wire through the short front carb outer sheath then through the choke operating arm clamp. Make sure the chokes are fully open and the choke knob isn't quite seated on the inside bracket. Leave about a 1/8" gap. Clamp the inner wire to the rear carb, then the front carb. Give it a try and see how it works. Shouldn't feel any different than a single carb manual choke setup. The 1/8" gap between knob and bracket is so you can feel the chokes fully open. You can set the knob up so the chokes are open when the knob is seated, but I like being able to feel them seated. When driving, check the knob once in a while to make sure it hasn't backed off which closes the chokes. More than likely it won't, but once upon a time I had a flathead powered car that would vibrate the choke closed so I got in the habit of checking the knob now and then.
Are sure you don't have the linkage for a Weiand 4x2 like the one pictured below? Wish i Had a better pic. Sorry Troy
Duane, thanks for the pictures. I did come across your picture of the Horne earlier. I am having a hard time seeing how the primaries pick up the sencondary linkage. The log manifold set up looks like something I could use for an idea, but still, even in that picture, I am having trouble seeing the link between primary and secondary. I look harder again. Kurt
Duane, I see how you have connected everything up but I am confused about where are you suggesting that the throttle peddle linkage attach, either cable or rod?
Hello..I know you can't see through the carbs, the two primaries are connected together with center pull ball, on the regular linkage side, a cable with ball snap works great.. plus the choke..Not to hard to figure out.. Duane..
Here is what I have. I am ***uming that the linkage set up here as pictured is how it should be set up on the carbs. To me, it appears that each primay is independantly connected to a secondary and the secondaries are linked to each other. What is the advantage/disadvantage of this versus what Duane has got going. Who is a supplier of cables with ball snap ends?
O.k., from the Eelco website. Description states that the leg for front carb is folded in for packaging...so forget the previous post. Now, which leg is the one that is folded in? I know it shouldn't be this difficult, but its got me scratching my head.
Hello..I will get a picture of the ball linkage with center ball pull..When you see the picture you'll understand..Lokar makes the cable with the ball snap end.. Duane..
Here is a staggered 4 x 2 linkage...looks a lot like what I've got less the throttle extensions. These linkages are the same...can't work for an inline 4 x 2. Well, its off to the hardware store to get some rod material for linkage Another feather in the Eelco cap...Will Eelco be at the top of the list if it ever gets made?
I have an inline 4 setup and I was going to run the middle two together in sync (or linked together). That means the middle two will have an attachment somewhere in the middle link to the gas pedal. You then need to figure out how to get linkage to the outermost carbs. The radius from the pivot to where the linkage attaches on the outermost carbs will have to be less than the radius of the pivot to the linkage of the middle two carbs. Use a slide linkage then for the outermost carbs. Don't expect you to really follow this, but maybe try sketching and taking measurements of your set up. Trial and error may be best for this. Good luck
unless...could this linkage work if the carbs. were set up with the primary and secondary carbs. staggared (but in line)? Primary-Secondary-Primary-Secondary in a line... What will provide better fuel distribution during primary function and also while all 4 are dumping...P-S-P-S or S-P-P-S? I may have to eat crow on that last jab at Eelco.
My 4 in a row progressive's do primary (rear), secondary (2), primary(3), and secondary(4). I think this gives good fuel distribution throughout the intake plenum.
Your Hemi will be happier with straight linkage, and mileage won't be noticeably worse...besides, it's a hot rod right? Why make things harder than they have to be? Straight linkage:
Hello..If the linkage is for a Hemi..NO prgressive, the engine will need all the gas... Didn't know it was a Hemi.. Duane.
It's easy to over-carb at my al***ude...I think it was just killing me to figure out this Eelco set up....with it working properly, I should also be able to lock them all together if needed. Of course that would also mean re-jetting my secondaries if needed when I come down out of the clouds...I am at an average of 7500 ft. I still would like to see some of those other pictures you mentioned Duane
JM2¢: All 2 × 4 360° manifolds (divided single plane) use the rear carburetor as the primary and choke - the fact that the 2 barrels aren't centered in the manifold doesn't seem to hurt, every manifold is like that including the original hemi. Based on that my preference would be to use #3 (counting from the front) as the sole primary, then #2, then # 1 & 4, but the linkage will be a bit complicated. Next choice is #1 & 3 for low speed, 2 & 4 for secondaries. As to simultaneous ("straight") linkage: which engine it is isn't relevant, and they're all going to be at full throttle together regardless of what linkage is used. The only thing progressive does it retain the best starting, idle, & part throttle characteristics, and good enough fuel distribution at mid-range for good mileage. More carbs open = less vacuum = more gas. Not what you want. Straight linkage will need richer jetting than progressive for good response at every throttle position except full (where they will match), idle quality will be worse - even though mixture distribution looks better, the reduced vacuum signal ruins it. The proportion of arm lengths determines how far the primaries can open before the secondaries open, but all must reach WOT at the same point no matter what. Typically, the progression varies from the primaries 1/3 to 2/3 open before the secondaries crack - and that means that the connecting point secondary must be 1/3 × to 2/3 of the length of the connecting point on the primary arm to do this. 1/3 primary only to 2/3 both ratio may not be enough for a small engine and heavy car to cruise without using the secondaries, using 1/2 - 1/2 allows higher engine RPM on primaries only for better mileage. The return spring should be at 90° to the primary arm at idle, and I suggest a second spring at 90° to the WOT position (but be careful that one does not pull the other over-center). All levers should be as long as possible for best accuracy in adjustment, and should be roughly vertical at mid-range. The levers from both primarys must be exactly the same length (between throttle shaft and heim joint), and operate at the same angle, the secondaries the same (although obviously different length and angle). If they were solidly connected, all that would happen is that all 4 would open together, and stop when the secondaries reach full throttle. The link between the primary and secondary slides freely until it reaches an adjustable stop. Adjust the individual levers first to the desired ratio: 1/3 - 2/3 means the secondary arm is 2/3 the length of the primary, etc. If you want 1/3 - 2/3, the block is at 1/3 of the link length, etc. Test, using 1/3 as ratio of choice: 1. move the throttle slightly from idle stop 2. both primaries should move immediately and exactly the same, but the link connecting them to the secondaries slides freely without moving the secondary levers 3. move the throttle to 1/3 open 4. the sliding stop on the connecting link now contacts the secondaries 5. opening beyond this point opens all 4 carbs, with secondary moving much faster 6. all carbs reach full throttle just as the linkage bottoms out 7. release the throttle, and all linkage returns to normal
Well put Panic. I've moved my primary carbs to #1 & #3 position. Secondaries now in #2 & #4 postion. Just finished primary linkage and now working on secondary linkage...I may be held up on my arms...I will need to dig around some boxes and see what I can find. I agree that running all 4 together is not the best for my situation...that is why I changed from a Weiand WC-245 to a Cragar open plenum design.
Forgot to mention...So far I have gotten around return springs. My pump rod fulcrums have beefed up springs which return each throttle closed very nicely...each carb has one of these springs.
Yeah, I know...this thing may end up in the odds-n-ends drawer. May also be entertaining for my 3 year old son to play with. I did manage to get it to function with some modifications. Several issues still present that need to be worked out. As it is, there is clearance issues with the center 2 carbs fuel fittings/lines. The 2 primary arms do not have identical hole spacing for linkage, so they are not truely in sync with each other. The secondaries are not moving fast enought and do not hit wide open with the primaries. I will have to work on getting a matched set of primary arms first and then get the secondaries dialed in. Any suggestions or comments are welcome. I do like the look of this linkage set up as opposed to others I have seen...I just need to get it to work. Remember, my carbs are set up now with the leading one being a primary, and then the next as a secondary, and so on...P-S-P-S. Here are a few photos from today. Feel free to resize and post them in this thread. I'm not picture posting savy. Thanks, Kurt http://www.directimagehost.com/is.php?i=151458&img=100_1069.JPG http://www.directimagehost.com/is.php?i=151459&img=100_1070.JPG http://www.directimagehost.com/is.php?i=151453&img=100_1064.JPG http://www.directimagehost.com/is.php?i=151460&img=100_1071.JPG
The 2 primary arms do not have identical hole spacing for linkage, so they are not truely in sync with each other. Tried flipping the arms end for end? The secondaries are not moving fast enought and do not hit wide open with the primaries. Use holes closer to the throttle shaft to speed it up.
Hello..Not sure about the primaries being 1 & 3..I would run 2 & 3 as the primaries. You should get better fuel/air distribution.. duane
Too many cooks in the kitchen. . . Figure out your linkage and run 'em the way I had 'em marked. They'll be fine. If you decide you want to run them all together, without progressive linkage, let me know and I'll send you the right jets and more extended bleed-screws. Plan on being married to them if you run 'em all straight. . .
I agree Max, I will run them progressive, that was never a question for me. The only change I am now considering is placement of the primaries. Instead of both in the middle, I'm thinking about staggering the primaries. I will consider you as the last word on this idea...I don't think it will make any differance really. As a note to everyone, Uncle Max did the build on the carbs pictured in my last post. I couldn't be more happier with the end product and Max is great to do business with. Please send him your business. Thanks again Max, Kurt
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