Some years ago I converted my '63 Fury from a 2 to a 4bbl with dual exhaust. Having encountered some engine stumbling problems when coasting or at idle I've pretty much ruled out a vacuum issue; but can't say 100% after doing more research on the carb I have on my motor. I had also switched to electronic ignition some years back. I can't recall where I got the carb anymore; but the # is 4131S Carter AFB. I find this was the carb put on 426 and 400 motors between 1964-1967. I had installed a riser as the rear throttle plates were too large for the manifold to chew. Seems like too much carb for the car but yet earlier 318's as many of you know (late 50's) actually had a factory dual quad option think with a pair of 400CFM's. Anyone have any advice for the better carb to put on my motor? I'm going to trick the motor up a bit more when I rebuild it; but only a mild upgrade in mind right now. Thanks.
Carb for Poly 318 Motor?
- Thread starter Ron H
- Start date
rumblefish360
Well-Known Member
Use a thick Edelbrock carb gasket?
There in the area of .333 thick.
There in the area of .333 thick.
I was wondering what size (CFM) carb is preferable. My guess would be btw 500 and 600. The thicker gasket sounds like a great idea for ensuring no vac leakage. What I had read on the Carter AFB's Quadrajets is the primaries shaft can wear and create an vac internal leak. Then rebuild is necessary. Since I'd be facing this it would be a good time to just change out carb for one that's more in line with the motor. Since the one I have is for the 426/440 motor it's more than I should be running on my 318.
rumblefish360
Well-Known Member
Well, not exactly. Size of the carb that is. It depends on what exact carb you have because the 440 did come with 630 AVS's, 600 AFB's and the large TQ, as well as 750 cfm units. In order to use ANY carb, it has to be jetted properly.
The thick gasket recommendation was because the factory used a thick gasket. Not the thin 1-16 paper gasket commonly used.
Oh, ether the 500 or 600 would be just fine.
The thick gasket recommendation was because the factory used a thick gasket. Not the thin 1-16 paper gasket commonly used.
Oh, ether the 500 or 600 would be just fine.
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I would get a new Edelbrock 1405. Troubleshooting an old carb is for the birds. I am running this carb on my poly with several mods and it screams. Running it at 17* initial, opened up the manifold, head work, valve job, headers out to 2.5" exhaust and it has never acted like it needed more or less carb. It is 600cfm and is plenty for my my car.
I opened my manifold up to accept it and am using a 1" phenolic spacer .
I opened my manifold up to accept it and am using a 1" phenolic spacer .
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