Reply to "Questions regarding George's 275/285 Custom Street Cam Profile"

Yours is pretty simple.

37mm chokes.

Idle: 120 holder, 66-67 fuel. For that you need to use a 65 fuel and drill it out with a pin vise to get that size. 65 is too lean and 70 is too rich.

Main: 140 fuel. 160 air. F7 emulsion tube

Pump jet bypass valves: .55

You can run the mains down to 125 and up to 170 on the fuel. Try the 140's. They SHOULD be all you need even on a track day.

What is important is that you need to keep the proportion of the fuel jet vs. air jet the same as in the 140/160. 170f for instance would use a 195 air.

If you have an exhaust gas analyzer, throw it away. All it will do is confuse the Hell out of you. Webers are old school. They will not tolerate scientific analysis and will defy logic.

They also need a lot of initial timing. 16 degrees for a start, and like as fast of an advance curve as you can get octane for. Kind of difficult to get the car to idle at 650 with that much advance.

36 degrees total but they like it all in by 2,000 to 2,500 engine rpm. Most cars will ping really badly on that with pump gas these days.

Final suggestion. Iregardless of what you wind up with jetting on the carbs, they will have the tendency of fouling the plugs. Mostly from pumping the accellerator to start the car cold.

They can be difficult to start cold. Cold for Webers is under 70 F.

If it wasn't for starting a cold engine, you can actually run .9mm pump jet relieve valves but the car becomes very difficult to start cold. .55 is the best compromise.

Check what is in your carbs when you get them. Some have ZERO's, i.e., plugged up, in them new.
I recommend using the P-E Ignition with them. It is the only ignition that I know of that will fire a fouled plug. MSD will not.
It also retards the timing when starting the car so it is easier to turn over. A lot 10 or 12 degrees. Really helps on a hot engine too.

If you are running iron Ford heads and using an AF32 plug, go one hotter to AF42. It helps.