Maybe somebody can help me figure this out. I've got a '70 Chevelle with a 327 engine supposedly from a '67 Corvette (based on block numbers). The car is new to me so I've been doing lots of maintenance. Yesterday was ignition day. The car got new plugs, wires, distributor cap, rotor, points, and condenser. I did this not just because the parts were old, but I was getting some knocking (even with a bottle of 104 in the tank), and the car was hard starting, like 'rumph' then stop while cranking. I concluded this was probably the result of having too much advance, so it was my plan to deal with that once everything was replaced.
After getting all the new parts installed, I disconnected the vacuum advance and plugged the tap at the carb, and set the dwell at 30 degrees. It moves less than 2 degrees from idle to high RPM, so it seems alright. Now this is the thing I can't explain. I have an advance timing light (with the knob). I checked the timing at curb idle with the vacuum advance disabled, and found that it was running at 38 degrees! I definitely was on cylinder #1 (front driver's side bank), and the wires are all hooked up according the 'normal' factory diagram. I was afraid that there wouldn't be enough adjustment to get back to just a few degrees, buy we tried that, and got as low as 10 degrees, but the car would hardly run. Also, after you raced the engine, it wouldn't go right back to idle, but would hang up a high RPM and eventually drop to idle. To make a long story short, we set the timing back to where it was, and backed off 5 degrees. This is probably near perfect as I now just get an occasional knock under hard acceleration, and the starting problem has gone away. I'm frustrated though because the 'science' doesn't seem to be working. The plan was to verify about 4 to 6 degrees at curb idle, and with the springs off the centrifugal advance, at about 2000 RPM (or so) check for 36-38 degrees of total advance. The centrifugal advance parts look ok, and I operated them by hand. Could they be bad? Also, the harmonic balancer is keyed to the crank shaft right? It can't be put on wrong (or can it?). Any input is appreciated. Gary ----------------------------------------------------- To Unsubscribe please visit www.chevelles.net/list.html To start a new topic, send mail to: [EMAIL PROTECTED]
