Stovebolt.com Forums The Shop Area The Engine Shop Rochester 4 Jet versus Quadrajet

Maybe I’ll consider EFI. I need to investigate what intake is required before I spend any money.

QUOTE Lugnutz:

"I could swap to a correct SBC intake, but then I’d need to change valve covers for the oil fill and then my 283 would look just like every other 350. I wanted to keep the vintage 283 look."

"Maybe I’ll consider EFI. I need to investigate what intake is required before I spend any money."

?????

Jon

A Carter WCFB would probably be the best compromise between performance and OEM appearance, followed pretty closely by the Rochester 4G.
Jerry

Would the Carter WCFB be compatible with this intake?

Not sure I agree with your priorities.
You spend far more time driving it (when the manifold and valve covers are anything you say they are) than conversing with admirers with the hood open.

Yes, Jon should be able to provide a part number for a WCFB that would be a direct swap for the OEM Rochester. They will both have the same footprint on the manifold.
Jerry

EFI?
You have a new job: learning EFI...

I’ve done EFI on a run stand with a 2003 LM7 Silverado truck engine. Wasn’t bad at all. Just needed to follow the Holley Terminator X instructions.

Holley also makes an EFI kit to replace a carb.

As far as appearance goes, versus changing the intake and valve covers (which make it look like a 350ci) . . . .
I started with a pile of original 283 parts. Rochester 2Jet carb, valve covers etc. Got 15 MPG city last time I checked. Power isn’t what I thought it would be, but it drives nice. Since I have a 4 barrel intake I thought I’d search for a carburetor too. Looks like a R4-Jet would bolt up but I wanted to explore what other options I might have. Seems the adapter plate is NOT a recommended option. Now I understand my options.

I like the way the 283 looks with old school valve covers and oil fill tube. To each his own I guess.

For what it may be worth, in high school I bought a nice used 1958 BelAir. It had the 283 with stock four bbl and after 6 months I decided it was a horrible carburetor. Extremely hard to get it set right and extremely easy for it to get out of adjustment. Wasted a lot of gas and a lot more time. Two years after I did that, a friend bought a 1958 with a 283 and a stock 2bbl carburetor. His started easier, ran better, did better in cold weather (which we got plenty of), got better gas mileage and required zero tinkering. I mean he never had to do anything to it. If fiddling with an old and probably over-worn carburetor is what you enjoy, I'd say that 4bbl will be a lot of fun for you. But I would bet the Rochester 2bbl (which I've decided was a very good carburetor) might be the best choice. Later another friend bought a 1966 Malibu with the 283 and 2bbl...same exact story. It ran better, got very nice gas mileage and wasn't needy of attention. I rode in it on a 300 mile trip once and at 70 it had plenty of power left. Plus by that time GM had abandoned the rope rear seal and so the engine didn't constantly dribble oil everywhere. Good luck no matter which direction you go.

Caviat - I no longer build carburetors, so the following is information, NOT an ad:

If you were to acquire a professionally restored ORIGINAL Chevrolet 283 Rochester 4-G, AND a professionally restored ORIGINAL Chevrolet 283 WCFB; and take them both to a mechanic you trust.

Instruct the mechanic to install his choice on your engine AND LOCK THE HOOD without telling you which one he installed.

Drive 1000 miles, and keep records of fuel used, driving impressions, etc.

Return to the mechanic and have the other carb installed and lock the hood.

Repeat the 1000 miles over similar conditions, taking notes.

At the end of the second thousand miles, compare the notes. You will not be able to tell if the mechanic actually changed the carbs, or not.

Yes, the Q-Jet is slightly more advanced in design than the 4-G; but the real argument for the Q-Jet is the spread-bore design for LARGER engines. The spread-bore design has no significant benefit for a basically stock engine as small as a 283. How much is slightly? Well, maybe give the Q-Jet 95 out of 100 and the 4-G 89 out of 100. BOTH would be a letter grade of "A" (pretty good ), but the Q-Jet would rate a A+.

Yes, the AFB (the real ones, not the modern imitation) is slightly more advanced than the WCFB. How much? Give the WCFB a 90 and the AFB a 94 (the Q-jet gets the 95 because of the spread-bore design (for larger engines).

Both the Q-Jet and the AFB can be tuned more easily than either the 4-G or the WCFB, but for a basically stock engine - who cares? If you are building a race car, then other priorities (what kind of racing, etc.) would need to be considered.

As far as NEEDED CFM is concerned: Carter published CFM ratings on only one WCFB, the 2493s, specifically designed for RACE ONLY on a Chevrolet 283 in 1957. This carburetor was rated 380 CFM.

WCFB flow ratings [thecarburetorshop.com]

My guess would be if Mr. Duntov thought he needed more than 380 CFM, he certainly could have had it!

Jon