A/F Ratio

[foxtrot]

Is it true that most cars run an A/F Ratio of about 14.5/1?
Should cars with a lower compression Ratio be run a little richer?
Does an Edelbrach carb out of the box run a 14.5/1 A/F ratio?

 

[megaladon6]

for emissions purposes, modern cars usually run 14.7:1, however the best power is considered to come from about 12:1 in most cases. it really depends on the engine build, operating range, usage...

 

[Doober]

Most carburetors are set to a specific range, meaning for the ideal a/f it will have to be tuned for your specific engine (but you could probably get by with putting one on so long as it's a reasonable cfm rating). Instead of using a computer with efi and changing fuel tables (how much fuel is applied depending on throttle position & rpm, in a nutshell), jets and other things are changed to tune the fuel curve of a carburetor. People don't believe it, but for many engines you can tune a carburetor to run almost as well as fuel injection. You can read books & books on carburetors and still find there's more to learn, just as with fuel injection.

 

[megaladon6]

People don't believe it, but for many engines you can tune a carburetor to run almost as well as fuel injection

actually it's a proven fact that carbs can and do produce as much power as EFI when properly tuned. the only problem is that when the temp, humidity, or altitude changes, the carb is now out of tune. EFI retunes every few milliseconds.

 

[Doober]

Yeah, that's my only qualm with a carburetor.

 

[foxtrot]

Does any1 know what the stock a/f calibration would be for an 800CFM Edelbrach carb?

 

[Doober]

It depends on the engine combination, heads, cam, displacement are all factors. But if you mean the stock jetting, I don't know that, you can probably find it on their site though.