The outer ring on your harmonic balancer is more than likely not in the position it used to be in. The rubber gets old and the outer ring moves. After that your timing marks are no longer accurate. I have found that used balancers usually aren't any better than the one you are replacing.
Bill Vander Werf -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Krister Meister Sent: Wednesday, June 30, 2004 12:40 PM To: The Chevelle Mailing List Subject: [Chevelle-list] Timing? I understand the mechanics on timing (but I'm sure there's more to learn). All printed publications for my car (396 360HP option) says to have timing set at 4 degrees BTDC. I put my light on it for the first time and found the timing mark not even hitting the timing pad. My guess is that was set at 12 - 14 degrees BTDC. I adjusted it down to 8 degrees and brought RPM to 900 - 1000 and on any acceleration the exhaust just snapped the whole time. Moved it back to 10 degrees and it seems to run fine. Now for the questions: does 10 degrees BTDC seem reasonable? Any pros and cons for running here or perhaps 12 degrees BTDC. Not knowing the engine history - it runs like it has a mild cam in it as it does not idle below 900 RPM. My service manual says to pull and plug the vacuum advance and plug on the intake side when checking the timing - doing this - the car barely runs. Just looking for some feedback. Thank you. Krister Meister Bloomingdale, IL '66 SS #'s
