I am not sure if I understood you. Did you check the timing with the weight off?? Anyway here goes 1) The springs and the weights may have been modified. 2) At 2000 the weights could be advancing. If very light springs are being used on the weights 3) Yes the harmonic balancer could be bad.
To check the harmonic balancer, get the piston at TDC on #1, the harmonic balancer mark should be at 0(zero). If it is not then the outer ring on the balancer has slipped. Look to see how many degrees it is off zero mark, subtract this from your timing reading and this is your real timing.I would replace the balancer if it checked bad. ----- Original Message ----- From: "Gary Treible" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, October 13, 2002 10:27 AM Subject: [Chevelle-List] Timing Help > 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] > ----------------------------------------------------- To Unsubscribe please visit www.chevelles.net/list.html To start a new topic, send mail to: [EMAIL PROTECTED]
