super six intake and 318 carb

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bad440

bad440

everything,all the time..
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installing a 2 barrel intake and a teener 2 barrel carb.will it be noticably better power wise?already has an electronic dist with an orange box.
 
well damn ,it's running.so heres your answer...yes it has a noticable power gain.but,the idle is just a little too high.the idle adjustment screw is all the way out not touching the stop.needs to be 100 rpm slower.i adjusted the mixture screws with vac gauge.the engine runs much smoother with the two barrel.sounds better too.the carb came off a 318 itsa carter.it has a hole in each butterfly like you would drill in a holley so it will get more air at idle with a big cam.think it will idle down if i plug those holes?
 
Something's not right. I would put the carb on the bench and give her a look,before I started drilling holes. But before you do that,have you checked for vacuum leaks around the carb ?
 
Been a while since I worked on the BBD, but if the mixture screw is all the way OUT, you have a vacuum leak or you need to plug the holes in the butterflies. Solder works well ( bonds well with brass )
Did you rebuild the carb before installing? might want to go through it just to be sure you're not trying to adjust something that has issues to begin with.
The timing being a little too advanced can also keep the idle high.
 
it dont have a vacume leak,the mixture screws are adjusted with a vacume gauge to highest vac.19 inches .the idle speed screw is all the way out.
 
Those holes are used in 318's because they need more air at idle. You should be ok if you plug them. If you want a real noticeable gain in performance now that you have a 2BBl open the exhaust up and see how much better it runs.
 
Plug them.

Remember your 318 carb has different choke linkage than it's slant six brother so you'll have to fab up some sort of linkage deal if you want the choke to work correctly.
 
Put a piece of tape on the holes for testing, wont jack up anything if it gets sucked in. And ditto on the head pipe diameter, the old one is like a 1 5/8 puny weld slag choker. Install a 2.25 and rock and roll.
 
I've been running a 318 BBD on my slant for a year now. Great power (as you've reported) but keep an eye on that mileage, mine dropped considerably. I have the same issue with the idle screw all the way out, but its not worth me plugging the butterfly holes when I'll be going to EFI soon.
 
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