Technical Best 4 barrel for a 3000 lbs car CHEV 283 with two speed auto and 3.3 gears

Namely Studebaker Daytona Sport Coupe
Has 2 barrel Rochester now.
I was thinking a factory 4bbl inlet with 780 Rochester.
Has Power Pak heads, cast iron exhaust manifold into dual pipes.

Your thoughts?

 

A 780 on a 283...NOOO, that's WAY too large.

An Edelbrock 500 cfm AVS 2 will work just fine.
This would be a perfect fit -
https://www.edelbrock.com/avs2-500-cfm-carburetor-with-manual-choke-in-satin-non-egr-1902.html

Yeah, you "can" put a larger carburetor on...but why ? By doing the math, the 500cfm carburetor is even a little large. But it's a very good compromise for power and mileage.
Good mileage, good drivability, good power when needed, good adjustability.

A larger carburetor, you will give up many if not ALL of the above driveability situations. You want large, sure, you can put an 800cfm Holley on the engine. But everything mentioned above, will go to hell.

Sure, some will tell you that "his" car (actually engine !), runs great with a 650 carburetor. MAYBE it does. BUT, see above, the 500 will work...better.

I've tested a LOT of carburetors on various engines over my 58 or so years (I'm 73) of driving a hot rod of some sort. Unless you have a LOT of engine modifications, a light car, a low gear ratio, do yourself AND your engine a favor...go by the math and stay smaller.

Try these, BE HONEST when writing the numbers -

https://www.carburetion.com/Calc.asp

or

https://www.summitracing.com/newsandevents/calcsandtools/cfm-calculator

or

https://www.inchcalculator.com/carburetor-size-calculator/

Mike

 

Rochester 4GC is a natural
I dug the hell out of mine, back then.

 

Not only no b ut HELL NO. Actually the best carb for that engine is the WCFB that came on a 283 power pack. Anything over about 500 cfm is going to be to big for the pretty well stock 283 with two barrel heads.
A quadra jet might work if that is what you are thinking about as the air valves on the secondary are only going to open for the amount of air the engine wants no matter what the throttle position.

 

Put a q-jet on it . Won't give you more than you need .

 

That's what I thought , with the small primaries it'd maximise Torque up to around 4000rpm, and the secondaries would only dump as much fuel and air in as required,
Combined with a regraphed distributor to come all in at 3500-4000rpm and the closed chamber Power Pak heads, What's wrong with that combination.
Remember how a Quadrajet operates?

 

I have ran the Holley equivalent for years on a BBC. I have a shop local that does my stock Q-Jets, money well spent.

 

That 780 Holley should work just fine............................at about 10,000 RPM.

While a Q-Jet or a TQ, either with the appropriate intake manifold change (NO adapters) would be fine, difficult to beat either an original Rochester 4-Jet or Carter WCFB that the Corvette (other than dual quad) 283's came with originally. About 380 CFM.

Like Mike said above...........do the math!

In building an engine, math and physics are your two best friends; turn your back on your two best friends, and then your only friend is MONEY!

Jon

 

Ditto!

Pat

 

I ran a Q-jet from a 350 on a 283/4-speed with a factory 350 iron intake, no adapter. Ran great!

 

Just curious about your distributor advance all in RPM. How did you arrive at that choice? Seems very late.

 

Q-jet! Had this on my friends '63 Impala back in the late 70's. Ran great, good MPG's, NO bog!

 

The only issue with all these old carbs, is finding a good one. If you can do that, the WCFB would probably run great. A Qjet would probably run great.

Old carbs have been abused for decades, with wrong parts, worn parts, missing parts, and warped housings. Just beware.

 

I’m partial to the Summit carbs that are a copy of the old Autolite. No gaskets below the fuel level, so one less thing to leak. And they look pretty period correct. I’m running a 600 on a 302 Ford, it does a great job, not too big at all.

 

As stated above WCFB is a good one to use,but don't rule out a Q-Jet if you can build one, when done right they are hard to beat for all around use.

 

I'd look for a transmission that has more than two gears before I worried about the carburetor. Lot mor driveability and performance with better gearing. I have to wonder if more carburetion will do anything with only a two speed transmission.

 

I don't know where you're from, but I always see late '50s to mid '60s Chevy 4GC and WCFB carbs at the swap meets I attend in the northeast. The 4GCs are cheaper, and I bought a couple that were complete and free moving last year for ten bucks each.

 

I agree that a properly sized carb with vacuum secondaries is what's called for. I also have favorites in this group, but so long as you keep these criteria in mind, any will work. The deciding factor after purchase and installation is one YOU can tune. If you are more comfortable and have a bunch of spares for Holley, great. If you have the knack for Q jets, fantastic. If you or your buddies have WFCBs, parts and knowldege stacked in the garage, super.

 

Yeah! Because a 3 barrel has to use less fuel than a 4 barrel . . . right?

 

My problem with q-jets is that I can take them apart alright, but have never gotten one back together.
Holleys, webers, Strombergs and Carters i have no problem with...not sure what my problem is.

 

Large base or small base? Large base are still pretty easy to find, but the small base are getting difficult to find. IIRC, I got my last one from you.

 

My similar combination seems happy with a 570 Holley Street Avenger vacuum secondary carb.

Gary

 

It's that damn choke lever!.... Been their, done that...

 

Large. Chevrolet V8 engines used the larger base 4GCs right from the beginning.

 

Here's an interesting carburetor event that happened by accident. This may not be received well by all but since everyone is cloning everything I'll throw it out there. Recently we bought a "good" used Edelbrock that internally looks like it went down with the Titanic i.e gas was left in it for a long time. I got a little upset and went looking on Amazon for a rebuild kit and fell into the best 600 clone I have seen and it sells for $168 from Geluoxi Auto in TX. This thing works like a charm, comes with extra jets and other items and has sight glasses on both float bowls. It is in fact an exact clone of the Edelbrock 600 but I personally think quite a bit better. Since they are both made in China I assume what's the difference. Just saying you might want to take a look. Yes, I know it is not original or made in the USA but let's be honest, what is. The thing works.

 

Hook the internal lever to the choke rod. Drop it down in thru the hole in the top.Turn the carb up on it's side.
Align the lever with a screwdriver, thru the hole in the side of carb. Pop the choke mechanism on.

BTW, GM put Q-jets on the 230 inline SOHC Pontiacs... Same cfm rating as the one for the 500 Caddy. ;-)

 

Personal problem ....

 

Holley 600cfm 4bbl #80457S

 

Not beating up on you, problem is you don't understand how they work,, get a Cliff Ruggles book and you will be well informed