Quote:
Originally Posted by Isaac Zackary
All I know is that a lot of guys report lower temps at 16:1 AFR and leaner.
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Yes exhaust gas temperature drops off pretty rapidly once you go leaner than 16:1.
It appears that some where around 16:1 is the best mix of the highest temperature and most free oxygen required to burn exhaust valves.
About 13.2:1 makes the best peak torque, 12.5:1 to one makes the highest horsepower in a naturally aspirated gasoline engine. (turbocharged or supercharged gasoline engines use lower air fuel ratios)
I try to stay between 12.5 and 13.2 when the gas petal goes to the floor. But this doesn't always happen.
Does this carburetor you are going to use have a primary and secondary setup?
Or is it single barrel?
If its just single barrel with a metering screw adjustment then you are only going to be able to tune your idle air fuel ratio a little and you will be stuck with one air fuel ratio that stays fairly consistent through out your entire operating range. Unless you get creative. If the single barrel carburetor has a metering rod and spring setup then you will have some ability to tune cruise, part throttle and wide open, but you wont be able to run lean cruise, then go a lot richer for WOT like you want to.
The primary and secondary carburetors give you more built in ability to tune cruise, part throttle and then accurately dump much larger amounts of properly portioned fuel and air mix into the engine at WOT when you need power.