Have a Holley 750cfm model 4150 - 9379 on a 427 so. I decided instead of guessing that I'd take it somewhere and have them adjust it. Went to Carburetor Specialists in Marietta, GA and they basically took the emissions inspection computer and used it to tune the carb. Stuck the sensor up the side pipes and then ran the numbers for:
HC - Unburned hydrocarbons
CO - Carbon Monoxide
CO2 - Carbon Dioxide
When we first set it up we were getting roughly the following readings:
HC - 7000
CO - 7%
CO2 - Don't remember, but they were mainly adjusting using the HC and CO numbers
When they finished the numbers were:
HC at idle = 3200
CO at idle = 4%
HC at cruise (3300 rpm)= 650
CO at cruise = 5%
Wanted to know if other folks had used similar services and what results you got.
All I know is that the car idled and ran a lot smoother as I apparently had a mixture that was really rich. It also cut down on the backfires I was getting.
Other thing they recommended was to install a PCV and take the oiled K&N filter out and go with a higher flowing paper filter (with a note to change it frequently). Said the vacum level and richness was pulling
oil past the rings and also mixing fuel into the
oil.
Appreciate any comments and thoughts on this.
Thanks!
Holley carb tuning using emission computer
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