Technical 283 intake on a 327

As you noted in your post, the bores of many 283 intakes were too small for the larger carburetors without the use of an adapter.

One word here: DON'T

More words: if you follow NASCAR, think restrictor plate racing. The intake manifold will be the limited factor; however, the curvature of the adapter is such that the adapter is a further restriction. Result: any of the newer AFB's, either genuine Carter or other will actually run WORSE on that intake with the adapter than either the original Carter WCFB or the Rochester 4-G.

Now, in your words the "moral advice":

The genuine Carter AFB carburetors are slightly superior technologically to either the WCFB or the 4-G. Also, more tuning parts are available; BUT, much as I love my genuine Carter AFB carbs, both the WCFB or the 4-G, professionally rebuilt, are more reliable than the AFB. When I was still restoring carburetors, my shop offered a 1-year UNLIMITED mileage warranty with either the WCFB or the 4-G. Ask you modern salesman for the same warranty, and see what he/she has to say

Don't know why you are having issues with a 4-G; and not throwing rocks at anyone. You say you are having problems, so I believe you. Shouldn't, but you are.

My suggestions (moral advice ) would be:

(1) Get the 4-G professionally done (NOT an ad, I no longer have time to restore carburetors)
(2) Acquire a professionally rebuilt original WCFB
(3) If either a genuine Carter AFB, or other, is your goal, do it right, and change the intake manifold.

Jon

 

Jon,

Assuming that I do go with a new Edelbrock carb: Suppose I kept the original intake (283), and it ended up that it didn't need an adapter, but only a fiber heat spacer. That wouldn't cause an extra restriction would it, as compared to using the other period correct intake for a 327, but still used the fiber heat spacer to help with percolation, correct?

 

The raw exhaust would burn through it eventually.

 

Also, an AFB style carburetor won't directly bolt to your current intake manifold anyway.

 

Getting your current carb completely rebuilt by a professional is good advise. But are you sure that the erratic performance is the carb and not a fuel system or ignition issue?

 

IF the throttle bores on the new unit are larger than the throttle bores for the original carburetor in the intake, there will be a restriction, regardless of the spacer. If this is true, then milling the spacer to blend the flow into the intake would help somewhat as it would reduce the eddy currents created by the mis-match, but it would NOT remove the restriction.

Jon

 

Just went back and read the entire thread.

As a general rule, real carburetors, such as the 4-G, go bad over DECADES; whereas ignition components can go bad in the blink of an eye, or be intermittant.

From your comment about you doing the carb, and another gentleman doing the carb; I would highly suggest some ignition testing prior to throwing rocks at the carb.

If it ran good for awhile, it will continue to run good for awhile.

Jon.

 

I agree 100% + with this. A well done carb properly filtered should be a set it and forget it item for 10s of thousands of miles. Caveats for "us" are long periods of storage (weeks or months), modern fuel that evaps and turns to powder, and finding a proper fuel stabilizer to help mitigate that. Only regular running and a proper set up from the start will relieve carb woes. In 50 years I've run across 2 carbs that no matter what is done they remained faulty. 1 was a side draft for a Vette 6, the other was on a MK II Continental. Checks perfect, doesn't run right, verified with exact replacements. Other than some scientific xray exam nd wet flow testing I don't what coulda been done.

 

I got the edelbrock 1403 in and also the heat insulator gasket # 9266. Of course the edelbrock will bolt directly to the Rochester intake, but the butterflies are too large in the secondaries and won't fit in the openings. I was going to attempt to see if the heat insulator gasket was tall enough to allow the blades to clear, but it didn't occur to me until the gasket came in that it only has 4 mounting holes, and they're spaced for the AFB spacing, so the spacer won't bolt to my intake. I got online and checked Edelbrock's website, but they don't offer an insulator that will fit the Rochester carb mount spacing. So it looks like I will end up needing to find a 300hp 327 intake, casting # 3799349 after all. I should have known it would be too easy to not have to change the intake!

 

As it turns out, I may have to use an edelbrock intake after all. I definitely want to use the heat insulator, but I don't think Edelbrock makes a heat insulator that fits the smaller 4 1/4" bolt pattern of the older carbs. The only heat insulators I see they offter are 5 1/4". That means I don't have a way to use an original cast iron intake, an edelbrock and a heat insulator, unless someone knows of some options I'm not aware of. I don't want to use an adapter or spacer due to hood clearance issues.

 

Hey guys, have a head scratcher I figured someone might have run into in the past. I just bought a 283 to run in a project of mine, it is a 3849852 casting, I have several of them, the strange deal with it is that it has F03I6XF stamped on the pad. According to what I can find, that would mean it is a 69 350...it has the vent tube on the rear. Came out of a 56 Chevy, looks like they bolted the 56 intake and all peripherals on the 283 as it has the old school distributor and a Rochester 2 barrel. I am including a pic of the stamping so you can see I am not just drunk...anyone run into this kind of thing before?