New 350 290hp crate eng. 3 Rochester 2G carbs totally rebuilt. Edelbrock manifold. Eng. TDC -verified piston position, dropped in new Pertronix dist. with No.1 pointing to No. 1 cyl. all good right? Start engine and checked timing and vacuum with vacuum line going to gauge. This thing will only run well with 55 degrees advanced indicated @ 900 rpm idle and with only the middle carb working below 3000 rpm. To stay running I have to close the choke 2/3 of the way closed. Both of the outside carbs are ****ing air even though the throttle plates are all the way closed. If I block off air to the two outside carb the thing dies even with the choke wide open. How are the 2 outside carbs ****ing air with the throttle's closed? I have 18 in. of vacuum with the choke 2/3 closed. With choke open about 8 in. If you put it into gear it drops 500 rpm and barely runs. This engine shouldn't even be able to run with all of the above going on. I'm at a loss on what to do. I've been chasing this problem for weeks. And trying everything I can think of to make it better. Any ideas ?
Make block off plates and run the engine on just the center carb. You may have to block the idle circuit on the two outboard carbs and use a progressive linkage. Once you get the engine tuned and running right on just the center carb you can add the next carb get it running right, then add the third carb. read this... http://www.hotrod.com/techarticles/...ter_tri_power_tuning_secrets_1932_ford_coupe/
Both of the outside carbs are ****ing air even though the throttle plates are all the way closed. If I block off air to the two outside carb the thing dies even with the choke wide open. How are the 2 outside carbs ****ing air with the throttle's closed? Well they aren't closed then are they? Have your outside carbs had the full conversion done to them?
I thought this sounded familiar. http://www.jalopyjournal.com/forum/showthread.php?t=856636 Did you try the other advise?
I've got the same set-up on my roadster. And had pretty much the same kind of problems you're having. Here's my advice. Remove the two end carbs and make a block off plate to replace each of the carbs and make a solid gasket for each. Bolt the block off plates on and start the car. Set the timing and adjust the primary carb, get it to run good on just the primary. Then check your throttle plates on the two secondary carbs. There should not be any idle mixture screws on those, block off the idle screw holes with set screws and you can even epoxy the set screws in. You don't want ANY air leaking into the intake from those end carbs as this causes a lean problem, the more they leak the bigger the problem. Next it's time to see if the throttle plates seal up when closed, check that with a light under the base in a dark room, any light you can see around the edges of the plates is not good. You can also get some leaking through the throttle plate shafts. Those are the three most common sources for air leaks, it won't do any good to put the secondary carbs back on until you fix those problems, and the car won't run good untill you have good tight secondary carbs. Now, after telling you all this, my best recomendation is to have a good carb guy do the bases, unless you are well versed on Rochester 2GCs. I bought two new end bases from Charlie Price at Vintage Speed in Florida three years ago, put them on and the car ran perfect and the idle and throttle response is great. You'll notice I also have some 1 inch thick aluminum spacers under the carbs that I got from Dashman here on the HAMB. Once again, block off those outside carbs and get it to run on the center. The ends should not have any idle circuits in them, they are only for off idle use. Good luck. I'm going to bed!
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