I have a 1966 327/350 Vette with 4spd & currently running a Edelbrock 1405 without a choke. The engine was rebuilt (26 yrs. & 28k miles ago) and was bored .030 over with an OE replacement cam installed. The distributor is single point type with <.010 end play and a new VC-1810 (B-28) vac. can.The car has developed a banging noise & virbration at start-up. As the car warms and/or the rpm exceeds 950-1,000 the noise subsides.
Timing is set at 12* BTDC / 800 rpm / vac plugged (timing will fluctuate 2* while running). Advance is all in at 2200 rpm & 34*. Vacuum at idle is 18-19" (full-manifold) and steady except for a very faint flutter (about 1/2") that seems to coincide with the timing change. On quick acceleration the vac. drops briefly to about 3" & then back to 23". Settling back to 18-19" on de-acceleration. I have used carb. cleaner to look for vacuum leaks around the intake but have not found any.
Valve lash has been set to 3/4 turn past zero. Engine cold.
Is there something obvious here that I have missed ?
Timing is set at 12* BTDC / 800 rpm / vac plugged (timing will fluctuate 2* while running). Advance is all in at 2200 rpm & 34*. Vacuum at idle is 18-19" (full-manifold) and steady except for a very faint flutter (about 1/2") that seems to coincide with the timing change. On quick acceleration the vac. drops briefly to about 3" & then back to 23". Settling back to 18-19" on de-acceleration. I have used carb. cleaner to look for vacuum leaks around the intake but have not found any.
Valve lash has been set to 3/4 turn past zero. Engine cold.
Is there something obvious here that I have missed ?
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