Carb - Air/Gas Mixture Question
Thread Starter
Safety Car
Joined: Mar 2002
Posts: 4,366
Likes: 7
From: Las Vegas NV
Carb - Air/Gas Mixture Question
I can't tell by listening (not enough expereince yet) to tell if I'm running a little rich. How can I tell when I have the right gas/air mixture dialed in...is there a tool that I can purchase to hook up to the carb? SPECS: 1970 L46 (350/350), Holley Carb, Hooker Super Competition headers/sidepipes.
Thanks.
Thanks.
Racer
Joined: Aug 2001
Posts: 457
Likes: 0
Re: Carb - Air/Gas Mixture Question (Motor City Vette)
Use a vaccuum guage sensing manifold vaccuum. What you want to do is to start off with all mixture screws turned out 1.5 turns . Then, with the car running, you want to achieve the highest vaccuum reading by turning the screws either in a little or out a litte. You have to turn all of them the same amount whenever you do this. It requires some patience . After youve got the highest reading possible, take off your vaccuum guage and reconnect the hose you took off of the carb. Before you do this procedure, make sure your engine is at full operating temp. After you have done the procedure, you can adjust the idle speed to where you want it.
Dave
Dave
Racer
Joined: Dec 1999
Posts: 485
Likes: 0
From: MESA, AZ, USA
Re: Carb - Air/Gas Mixture Question (Motor City Vette)
Get an article on how to "read" your spark plugs. Doesn't take much driving to determine how things are going inside each cylinder. You do have to start with either new or clean plugs each time, but this is the way it was done before all those "high falutin'" computers.
Andy
Andy
Le Mans Master
Joined: Feb 1999
Posts: 6,807
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From: Hoosier
Cruise-In III Veteran
Re: Carb - Air/Gas Mixture Question (WATTAC)
An air/fuel gauge is the way to go. I have an Autometer gauge in place of my clock on the 72. Following the vacuum gauge carb tune procedure is pretty good for idle and low throtle but not close enough. My air/fuel is rich at low rpm's indicating that the air bleeds are too small.
