chev 350 carb question

Hey Guys, Dumb question time.I have a 4 bolt main 350 bored 60 over,9\1 compression stock cam, What size carb should i use for this engine? It's just for average drivability aplication. It currently has a holly 4360 450cfm carb on it now. Thanks for the sugestions.



- Gregg

 

500 cfm would be perfect. Vacuum secondary for ease of use and fuel economy.

 

There are formulas for this, but here is what I have.
350, 10:1 comp ratio .030 i have a holley 600 vac secondary basic model 4150/4160? not sure about the number.
Anytme I've seen similar motors calculated that was about what was recommended.

 

Or your basic 685 Quadrajet, I think Summit sells units based upon engine year. Go with a 1969 Car Carb and you will have good throttle response and mileage with all the CFM you will ever need when you stomp it. Make sure the intake is spreadbore though. The later year Quads lack adjustable idle enrichment screws, well they are covered up anyway.

 

Carb Calculations

CID X Max RPM divided by 3456 = CFM

or

CID X 2 X .8 = CFM

Both will work

MDM

 

carb calculation: 350 street engine gets a 600 holley or a 625 AFB or a Qjet

big block street engine gets a 750 holley or AFB or a Qjet

 

Exactley,,,I'm using a 1406 Edelbrock(Carter type)---600 cfm with no issues on a pretty stout SB.

 

I never had much luck with a 600cfm vac. sec. on my 350. My motor was fairly mild and I had to add a rear metering block and increase the jets sizes primary and secondary too many sizes to get it to not run too lean.

i switched to a 750 DP and like it way more.