Author Topic: Is my carb too big for my 383?  (Read 22531 times)

Offline 734406pk

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Re: Is my carb too big for my 383?
« Reply #90 on: September 27, 2015 - 02:53:03 PM »
Man you have chased your tail on this thing for quite some time. Made a lot of changes, non that worked. Your constant is the plugs if I am not mistaken? You need hotter plugs. Those autolite racing plugs run cool. You said they had a brownish "film or glaze" on the porcelain. Classic symptom of a plug not hot enough to burn off deposits, and cause misfire. This will cause the problems you are describing. Do yourself a favor and put in hotter plugs. I am sure the edelbrock tech line can get you close. I have been there. This will fix your issues.  good luck

Good call on those plugs! :cheers:
1973 Challenger 440 6 pack auto 3.91 rear
2012 Dodge Ram 3500 dually 6.7 Cummins Fleece EFI Live
1973 Challenger 318 2bbl auto 2.73 rear 22.5 mpg RIP
1970 Challenger TA 340 4bbl auto-Sold and sad
1999 Dodge Ram 3500 dually 5.9 Cummins Fleece tuned VGT-sold
1995 Kawasaki ZX1100E & still alive




Offline Strawdawg

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Re: Is my carb too big for my 383?
« Reply #91 on: September 27, 2015 - 03:26:34 PM »
Whether it was plugs, timing, or both, I am glad you got it running right after all this!

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Offline Bluemonster71RT

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Re: Is my carb too big for my 383?
« Reply #92 on: September 27, 2015 - 04:24:45 PM »
Excellent news! Which plugs did you go with? I checked the Eddy instructions on the Performer heads and they recommend RC12YC Champion (or equal) as a starting point. Major difference is the heat range (+4 steps hotter)and projected tip electrode. Drain the fuel out of the Eddy AFB carb and save it for something stock to mild. They work fine for that application as thats what they were designed for. Now for the tuning of the Holley SA... Set up your float levels and lock out the secondary with the black spring. Jet the primary on the rich side to start with and work you way to lean checking sparkplug color.  Its safer that way. There are plenty of threads and Youtube videos on the process. Congrats! :bananasmi

I went with the AR3934's and AR3935's I put the 35's in to see how they go. They are the hottest of the series for Big Block Mopar. I re-adjusted the rockers. I got one clacky one but it was set the same as the others. I guess I'll go one more 1/4 turn and see if that helps.   
1971 Challenger RT 383 4spd

Offline 734406pk

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Re: Is my carb too big for my 383?
« Reply #93 on: September 27, 2015 - 05:09:58 PM »
Ok see how it goes with AR3935. AR 3923 and AR 3924 are progressively one step hotter yet.
1973 Challenger 440 6 pack auto 3.91 rear
2012 Dodge Ram 3500 dually 6.7 Cummins Fleece EFI Live
1973 Challenger 318 2bbl auto 2.73 rear 22.5 mpg RIP
1970 Challenger TA 340 4bbl auto-Sold and sad
1999 Dodge Ram 3500 dually 5.9 Cummins Fleece tuned VGT-sold
1995 Kawasaki ZX1100E & still alive