View attachment 5654554 HI, fellow hambers can I get a procedure on how to get the three deuces set up to run on my hopped up 327 corvette engine in my 1934 5 window ford coupe. OR SHOULD I GIVE UP AND GO ANOTHER DIRECTION LETS SAY MAYBE SINGLE CARB??? View attachment 5654554
Lots of threads here with similar question. Of course the ultimate solution is not always the same. A common starting place is the suggestion to block off end carbs and get it running well on the single center carb.
Direct or progressive linkage? What size of power valve and jets installed? Have you synchronized the carbs? Distributor type? New or aftermarket carbs??
Here is a thread that Clive from Stromberg participated in. Worth reading, he knows what he speaks of: Let's build a Stromberg 97 3x2 | Page 2 | The H.A.M.B. (jalopyjournal.com) Ha! Asleep at the keyboard this morning....just realized they are 2GC's but still a good read!
On what appears to be an open hood car, I would get the 3x2's working right and not consider a single four barrel. Shouldn't be too hard to get those 2GC's tuned correctly as compared to dealing with old worn out Holley 94's or something like I fought for a while before I remembered I never open my hood anyway. And, nice looking engine by the way. Amazes me how many Corvette engines are in hot rods.
I believe there is a vacuum leak , all three carbs have idle screws is that correct or what? someone says blocking plates where do you get them?
John you can make your own out of scrap sheet metal. That is what many of us have done. A pic of the other side showing the linkage would be helpful. A true progressive linkage set up runs on the center using the outside carbs as secondaries or dumpers. In that vein they usually do not need idle adj screws unless you are running all three while idling with straight linkage. As dumpers a few mods are required especially sealing the throttle blades so that there is no leaks past the blades. First we need to know how this is set up to run.
..If they all have mixture screws and have no chokes; take end 2 off and blank them. Plug the fuel lines and run each one in the center and set it to your satisfaction. Do it with each one. This proves you have 3 good carbs no matter where you got them. Now add one at a time and set with unisyn. Summit sells them. If the outer 2 do not have mixture screws, disconnect the linkage and set the center to drive as 2 barrel. With the idle screws off the stop. With no air passing thru at idle a Unisyn doesn’t help. You can always turn in the mixture screws if you have them to use the system All the jets should be 52-54 and the power valve actuator spring free. The carbs need good vacuum to hold the actuator spring off the power valve plunger. Hopefully you don’t have a cam that cuts the vacuum too much. Good luck, I’ve run 3/2’s on a 350 with 9-1 and an RV 268 cam. The 3 carbs were from a 348 Chev and worked perfect.
I bought a 3 deuce setup from Charlie Price in Florida that was supposedly ready to run. I put it on a healthy 327 in a deuce pickup and fought it for 2 years. I sold the pickup to a man in England and when I shipped it I included an Edelbrock Performer intake, 650 Edelbrock Carb, Gaskets and Air Cleaner. After he'd had the truck for about 6 months he sent me an e-mail thanking me and said the 3 deuce setup looks good on his shelf.
I fought the 2GC carb set up on the 327 in my Roadster but have eventually gotten there. The center carb is...think of kind of it like the primarys on a 4 barrel. It should control the idle and set for light throttle driving and cruising. Best practice is to have bases for the outer two that do not have idle screws. They are available aftermarket if yours are not set up that way. There are original tri power 2GC carbs out there but $$ The two outer carbs have to have the butterfly valve plates close totally and tight up against the body. I had to hand work the plates with a file to get them to seal...no light visible thru them at all. If they aren't totally closed off tight, you will get lean cylinders as air leaks by them. Setting idle adjustment on the center carb will be unachievable too if the outer two are leaking air past them at idle. Then...pay attention to the geometry of the accelerator pump linkages. They need to allow for full throttle opening and will mess with your bell crank to shaft position...especially if the throttle shafts have been replaced and the accelerator pump bell crank is affixed to the shaft with a threaded fastener. Improper accelerator linkage geometry, if it is too short, can rotate the bell crank on the shaft where it looses its index and the throttle plates don't return closed all the way after full open throttle operation. This will again cause lean fuel conditions. Good luck...tri power carbs look cool..and can be made to work
You will find they ain't fun. I can offer you the 3 things that it takes, or took me, to get them dependable: ----absolutely, positively no vacuum leaks-anywhere-period. ---a bone stock center carb, no jet mods, cute tricks, etc., just a base carb. ---the end carbs MUST be for the ends, meaning the bases are blank with no idle screws etc. and the butterflys must seal tight, totally tight-see point 1. I got mine from Price, alum. base with brass Bfly that seals tight. After you have all this, make some block off plates, 2 ea., block off the ends and make the thing run perfect on the center carb. Drive it, don't idle it. The put one carb on, hook it up and repeat the run step, then add the 3rd one and repeat. If all is well you're about 70%. You'll find discussions about fuel regulators, linkage setups, line size, filters, air cleaners, spacers, and on and on. Did i mention flooding??
I have that in boxes if a trade can be made to save someone from the grief...Just saying it I can ease a burden.
If your your not using the outside carbs to idle and they were once a single. The mixture screws must be in all the way and the idle screw must be out far enough to not open the butterfly.
Make sure the end carb throttle plates are returning to the idle position. The ones on my 58 Impala would sometimes stick a bit open. That gives you a large vacuum leak at idle. I would start by disconnecting the linkage to the end carbs. Back off the idle (throttle plate position) screw until the plates close completely in the bores. Look down the carb throat to verify. Now adjust the idle screw until the throttle plates are just barely cracked open. Adjust the linkage to the end carbs to line up with the now adjusted throttle setting. See if that fixes the vacuum leak.
Front and rear carb should not have Idle circuits, nor should they have power valves. Bottoming out idle ckt screws doesn't work either as you need those two carbs to have the throttle blades 100% sealed at idle. You may have a cobbled up tri power someone tried to make work. You can buy the proper bases from Speedway or Vintage speed.
Your first post: different direction? - Dual quads (like Chevrolet used) are MUCH easier. If you are set on tripower: If your time is worth more than "Do you want fries with that cheeseburger?", the absolute cheapest way (regardless of the cost) is to find a set of factory 348 carbs. If you time is worth nothing, you may be able to cobble something together (many have). Jon
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