63 Overheating?

[Lyle Hayer]

Hello to all
I recall someone(Joe,Wayne or Duke)discussing the vacuum advance and timing on the base engine 63 has a greater effect to overheating than the higher hp engines in a recent post. I can't find the post, maybe someone can straighten me out. My 63 Coup has the 327/250hp. I been running extremely hot lately. I replaced thermostat, checked water pump, flushed rad and engine and temp hasn't dropped. Even with an external block reading. Timing at 0 degrees at 700 rpm. Question: Could the accel dual point dist. without vacuum advance have anything to do with it. I came back Sunday and I found a tiny crack at the radiator top return elbow to the overflow tank. Air in the system no good. After repairing the leak, what next can I check. Thank you for any advice.

[Wayne W.]

Re: 63 Overheating?

Your running an Axcel Dist. with no vacuum advance at 0 deg.?

[John H.]

Re: 63 Overheating?

Your aftermarket no-vacuum advance distributor is definitely contributing to your problem (assuming you've verified your temp gauge reading with an I.R. gun so you know what it's really telling you). I don't know how much centrifugal advance it's adding for WOT total timing or what the curve is, but it's certainly severely retarded at idle, which will significantly increase coolant temperature at idle and in traffic. Chevrolet quit using centrifugal-only distributors after 1962 for good reason. The distributor your car was built with originally (#1111024) provided 24* of centrifugal advance at 4600, and, more importantly, its vacuum advance unit provided 15* of advance at idle, in addition to the initial advance of 10* or so, for total idle timing of 25* (vs. the 0* you have now). I'm surprised it runs at all with 0* initial timing.

[Lyle Hayer]

Re: 63 Overheating?

You guys are scaring me. I just went out and rechecked the timing and dwell. Yes, it's 0* @ idle(650rpm) and approx. 8* @ 2000. Dwell @ 32*. The engine runs great. Accelerates fine. I rebuilt the original WCFB twice looking for a little more juice from the secondaries with no luck. The powerglide kickdown needs adjusting. But all in all,very dependable. I left the dist. in because it ran so well. Other than the dist. and intake manifold coming from a early impala, all numbers match. What I don't know is what was put into the rebuild engine before I purchased the car. I'm not at that cross road to open it up when it performs so well, (until now). Wayne, what about the accel dist. 0*? Thank for taking the time.
Lyle