Which is the correct A/F ratio ?

[Gaz64]

Originally Posted by Stephan427SC

Hi guys,
I want to set the correct A/F ratio or lamda for my engine ( Ford FE390 stroked to 445cui with 48 IDA Webers). I installed a oxygen sensor in exhaust on passenger side.....

I was told to set the A/F ratio while idling at about 14.9....what do you think ?

Is the engine with a 12 A/F ratio too lean ?

Can you get me some more information or tricks ?

Thanks,

Stephan

You won't achieve a satisfactory idle at 14.9:1.

12:1 is rich not lean.

12 parts air, 1 part fuel. Both by weight.