Friends:
This is my first post to this forum, but I've owned a 1965 Giulia Spyder for about 14 years. A few years ago my mechanic installed a pair of 45DCOE Webers on the 1600-cc engine, which has no other mods except higher compression. It runs fine at 5,000 ft altitude but not above 8,000 ft, where it runs rich and fouls plugs at low rpm. It's also hard to start at high altitudes (8,000 to 12,000 ft). First jets we tried were 180 mains and 120 air. Then we went to 190 and 115. Current jets are 200 and 110, respectively. All without much change--plugs are sooty, starting is getting harder.
Questions:
1) Is the stock Alfa ignition system capable of firing the plugs (NGK BP7ES) if the mixture is too rich? When starting at high altitude, the plugs seem to get wet, but the engine won't fire unless they are perfectly clean and dry. I'm considering a Centerline electronic distributor. Any experience there?
2) Is a 45DCOE too much carburetor for a stock 1600 engine? I don't know what venturis are installed.
3) I drive the car at altitudes from 5,000 to 12,000 ft, and I'd like it to function throughout that range even if I do have to change jets. The more I think about this problem, the more I think the ignition system is inadequate. What say you?
4) Is there a Weber 45DCOE jet size vs altitude chart somewhere? Any other appropriate archival posts would be helpful, too.
Thanks for your help.
Frank
This is my first post to this forum, but I've owned a 1965 Giulia Spyder for about 14 years. A few years ago my mechanic installed a pair of 45DCOE Webers on the 1600-cc engine, which has no other mods except higher compression. It runs fine at 5,000 ft altitude but not above 8,000 ft, where it runs rich and fouls plugs at low rpm. It's also hard to start at high altitudes (8,000 to 12,000 ft). First jets we tried were 180 mains and 120 air. Then we went to 190 and 115. Current jets are 200 and 110, respectively. All without much change--plugs are sooty, starting is getting harder.
Questions:
1) Is the stock Alfa ignition system capable of firing the plugs (NGK BP7ES) if the mixture is too rich? When starting at high altitude, the plugs seem to get wet, but the engine won't fire unless they are perfectly clean and dry. I'm considering a Centerline electronic distributor. Any experience there?
2) Is a 45DCOE too much carburetor for a stock 1600 engine? I don't know what venturis are installed.
3) I drive the car at altitudes from 5,000 to 12,000 ft, and I'd like it to function throughout that range even if I do have to change jets. The more I think about this problem, the more I think the ignition system is inadequate. What say you?
4) Is there a Weber 45DCOE jet size vs altitude chart somewhere? Any other appropriate archival posts would be helpful, too.
Thanks for your help.
Frank