Ditto, great information, really informative, and productive info, despite the hardship, appreciate the resolve. Cheers, Drewfus
In my humble opinion you need to set the center carbs to around 1 turn or less, See how it idles. set the end carbs about 1/4 and set the butterflys to closed or just barely open. The end carbs should not be in the equasion for idle as you use them for WOT only As far as it wanting to die when you come to a stop. set the float levels down. As far as the flat spot this is a function of the Accel pump. Set it up so that any throttle movement makes it squirt. This is really hard because most carbs are set to do this when the idle screw is set up for a single carb set up One of the greatest problems with multi carbs is that adjustments are off the charts from a single carb set up. With one carb you get the normal vacuume signal to the carb but with multi carbs that signal is divided between the carbs. When running on the 2 center carbs you will notice you only have to turn the idle screw half as far on each carb because each carb is running half the air a single carb would. I run tri power on a SBF Falcon and 2x4s on my roadster I really hope this will help you Fuzzy
Great set of responses. I'm getting ready to put a 6 deuce setup on a 428 FE and currently I'm totally lost on how to set it up. FE tri-powers are easy compared to an Edlebrock 6X2. Movin/on
Dickster27 ROCKS! I will post an update and summary next week when the parts show up. I have learned SO much about multi-carb setups over the last few weeks. Hopefully this thread will help the next guy out as much as it has me. Thanks everyone.
I have also saved this thread and learned more than I could get from a book ! I guess matching the carbs up first will bring less confusion when trying to adjust them later on . dickster27 you are the man when it comes to the carbs ! I would have never figured out the difference with the spay bars being high & low This is the best multi-carb threads I have read yet ! Thanks to all for all the great information !
I got back from vacation and got to drive the car. IT IS FIXED!!! Thanks everyone...especially Dickster27 for all your help and suggestions. Multi-carb intakes aren't so tough, as long as you take the time to read up on and understand the carbs you're working with. I've learned so much about Holley 94's and tuning them I feel very confident in setting them up. I definitely helps to find someone who knows what they're talking about and really pick their brain. IN SUMMARY, HERE'S WHAT I FOUND WITH MY SETUP (of course every single engine is different but hopefully some of this will help the next guy). 1. Power Valves need to be blocked off on all secondary carbs. I installed PV blocks as well as soldered the vacuum ports below the PV's. Make sure the gasket surface of the PV and the carb are true and seal completely (use the correct gasket). 2. I am running 4.5 power valves, but may try to see how the standard 7.5's work now that everything else is dialed. MY engine idle vacuum is 15 inches so keep that in mind when choosing YOUR power valves. 3. Make sure to COMPLETELY disconnect the linkage to the primary carbs before you use the UNISYN. One little lock collar on the secondary shaft screwed me up for quite a while. You should be able to drop you idle to the point of killing the engine. 4. FINALLY, AND MOST IMPORTANT!!! YOU CAN NOT RUN 1st GENERATION NOZZLE BARS IF YOUR CARBS ARE MOUNTED BACKWARDS ON THE INTAKE (ie bowls to the rear). This is crucial. I bought my intake assembled from ages ago and it was probably run on a drab/race car. The carbs were mounted backwards but I liked the way it looked so I kept them that way. I did replace the linkage with a progressive linkage however. If you think about it, on a drag car all you care about is acceleration, not braking. The first generation nozzle bars look like an arrow, with the idle tubes the same height as the bowl lip. Whenever you decelerate the fuel continues to move forward with momentum and because the idle tubes are so low on the first gen. design it actually allows fuel to flow over into the venturies and flood out the car. The second and third gen. nozzle bars are totally different with the idle tubes almost 1/2 inch above the bowl lip so the fuel cannot flow over into the venturies on deceleration. Dickster and I both did bench testing on this theory and it is exactly what my problem was. I can tell you that with the 1st gen nozzle bars I could smell ultra-rich exhaust even when I let off the gas cruising down the highway at 60 mph, and it would literally flood out at stop lights. Now, with the second gen nozzle bars installed it has no hesitation during braking and when I let off the throttle at 60 mph it doesn't change the exhaust smell. I'm sure I've forgotten something on this list so I'll edit it over the next couple days. Thanks again everyone and good luck with your own 6X2 dilemma.
Best 6x2 thread EVER! Thank you for being so imformative and providing updates as you went. Happy endings are good and "I love it when a plan comes together!"
Another update for those who care.... I've put another 200 miles on the car this month and have come to the conclusion that you DO NOT want to run 94's backwards. Yes, it works and I don't have anywhere near the problems I was having with the 1st gen. nozzle bars, but it still isn't quite right. If I have to stand on the brakes because some grandma ahead of me thinks saving a squirrel is more important that getting rear-ended at 40 mph it will flood the car (not that it has happened.....but if it did). The only way to resolve the issue completely is to run the carbs the way Henry wanted....with bowls in front. I can say that the car runs great as it is, but it won't ever be perfect with them setup backwards. As far as running great, the car doesn't puff black smoke unless you are REALLY bumpin' the throttle and it smells nice a clean. I can listen to both headers individually (its a T so I can lean out each window as I drive) and they sound exactly the same with no pops, knocks, or pings. I really think the uni-syn takes full credit for that. The car still take a minute or two to warm up because there aren't chokes, but after about 30 seconds of 1200 rpm you can get out and let her idle on her own. Idle is about 680-700, but does seem to climb a little as she really gets warmed up. The vacuum gauge is reading a fairly steady 16 inch/lbs at idle which I'm happy with. If I make any updates or changes I'll definitely post to the thread. Once again I appreciate everything that everyone has contributed to this thread. Hopefully this will help the next guy overcome the "fear" of a multi-carb setup.
thanks for a good read Im running the same manifold but with rochesters still in the build up will save this thread
Ok, so it is cold here and that means I'm going back to work on the hot rod. I noticed that my linkage setup has a flaw....the main cross shaft that controls both banks of carbs is too small. The linkage kit from EELCO came with .25 inch shaft, with 2 pillow block bearings. The problem is that the shaft will flex causing the two banks to be out of sync. I want to step up to 3/8" shaft or something comparable but haven't been able to locate a source for small shaft (with a flat side) or small pillow blocks. Anyone know of a good source for smaller bearings/shaft? My local store is more industrial/agricultural based and doesn't show anything smaller than 3/4" or 1". Thanks.
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