Is there a Tie?
By post 4 plus 9 and 10 the original question had pretty well been answered, but I'll still add my two cents on AFR's. Actually, 14.7 is a rounded number. Some sources differ a little but most quote the number 14.68:1 as stochimetric.
The standard narrow band Oxygen Sensors that are used on the standard Gen III small blocks (plus most other vheicles) switch back and forth at stochimetric (14.7:1 AFR) for gasolline/petrol (I'll check on E85). This is the most emission friendly AFR for the environment and is mandated by the EPA in the USA for most operational situations. Start up enrichment and Power Enrichment allow the mixture to go richer. For normally aspirated engines, I try to stay between 13.0:1 and 13.2:1 AFR. Engines with power adders typically run richer, even around 11.0:1 because the added fuel is used in some cases for cooling or to avoid knock.
The standard narrow band Oxygen Sensors that are used on the standard Gen III small blocks (plus most other vheicles) switch back and forth at stochimetric (14.7:1 AFR) for gasolline/petrol (I'll check on E85). This is the most emission friendly AFR for the environment and is mandated by the EPA in the USA for most operational situations. Start up enrichment and Power Enrichment allow the mixture to go richer. For normally aspirated engines, I try to stay between 13.0:1 and 13.2:1 AFR. Engines with power adders typically run richer, even around 11.0:1 because the added fuel is used in some cases for cooling or to avoid knock.
