Timing Issue 1964 327/365hp

[Bryan W.]

[Richard M.]

Re: Timing Issue 1964 327/365hp

Bryan, It's possible the counterweight spring(s) disconnected. You'll have to pull the rotor to check.

However, note the rotational position of the distributor. The window should be facing front somewhat. A photo with shielding removed would help.

Your timing test was normal. You'll get about 15* more Adv with VAC connected. It was not right because you retarded static timing too much with VAC connected.

You want to disconnect the VAC hose, plug the hose, then set static timing to spec(8* or so iirc), at idle RPM spec. You may need to raise idle a bit. When you reconnect VAC, you should see apx 15* more advance, around 23-25* ideal. You will have to adjust idle down a bit back to spec after VAC is reconnected.

If by chance the window was off the mark before you reset timing, it is possible the distributor turned by itself. This can be caused by a faulty tach gear. It can jam the mainshaft with enough force to turn the distributor.

Oddly this happened to me on a few occasions over the years. Once on my wife's '63. She was following me after a car show and broke down. I went back, It was backfiring on retry, flame out of the carb, etc. I pulled the shield, turned the distributor back by eye, unscrewed the tach drive brass housing/gear assembly, and she drove it home fine.

I rebuilt the tach drive and new mainshaft and all was well after that.

Rich

[Bryan W.]

Re: Timing Issue 1964 327/365hp

Bryan, It's possible the counterweight spring(s) disconnected. You'll have to pull the rotor to check.

However, note the rotational position of the distributor. The window should be facing front somewhat. A photo with shielding removed would help.

Your timing test was normal. You'll get about 15* more Adv with VAC connected. It was not right because you retarded static timing too much with VAC connected.

You want to disconnect the VAC hose, plug the hose, then set static timing to spec(8* or so iirc), at idle RPM spec. You may need to raise idle a bit. When you reconnect VAC, you should see apx 15* more advance, around 23-25* ideal. You will have to adjust idle down a bit back to spec after VAC is reconnected.

If by chance the window was off the mark before you reset timing, it is possible the distributor turned by itself. This can be caused by a faulty tach gear. It can jam the mainshaft with enough force to turn the distributor.

Oddly this happened to me on a few occasions over the years. Once on my wife's '63. She was following me after a car show and broke down. I went back, It was backfiring on retry, flame out of the carb, etc. I pulled the shield, turned the distributor back by eye, unscrewed the tach drive brass housing/gear assembly, and she drove it home fine.

I rebuilt the tach drive and new mainshaft and all was well after that.

Rich

[Owen L.]

Re: Timing Issue 1964 327/365hp

Since the distributor appeared in the correct position, could this be a timing chain issue? The original plastic coating on the camshaft gear wears out, disintegrates and allows too much slop in the chain...

[Duke W.]

Re: Timing Issue 1964 327/365hp

It's virtually impossible to check/set initial advance on a 30-30 cam engine because the centrifugal starts at 700. Good luck getting it to idle stably below that speed long enough to get a decent reading much less actually adjust.

For this reason instead of setting initial advance, set total WOT advance by revving the engine to above the point of maximum centrifugal and set it in the range of 36-40 that the Chevrolet Power Manuals state is the best power range. Since the full OE centrifugal on this engine is all in at 2350 you only need to rev it to between 2500 and 3000.

Of course, all of the above is done with the VAC signal hose disconnected and plugged with a golf tee.

Say you set total WOT advance at 38. Then if you want as a reference you can try to check initial at below 700. OE full centrifugal is 24 so initial should read 14, however it will probably read 16-17 because the OE timing tap is NOT accurate on SHP engines with the 8" torsion damper. If you use a dial back timing light and move the damper notch back to zero on the tab the reading should be accurate.

Connect the VAC and set idle speed to 900. Total idle advance should read in the low thirties - 14 initial, 16 vacuum, plus 2-4 centrifugal because it starts at 700.

Of course I have no idea if this engine has an OE equivalent 30-30 cam or the OE spark advance map, but you should be able to determine the entire spark advance map with a dial back timing light and compare it to OE specs in the shop manual and AMA specs.

The single point ignition system is quite reliable - in my experience more reliable than any electronic system including the GM TI and HEI systems, which can fail suddenly without warning. The single point system usually gives you some warning, but the distributor is the most overlooked system on the engine even though its set up and performance are critical to achieving maximum performance and fuel economy. There are probably many out there that have never had a decent overhaul since they were assembled by GM decades ago.

I don't know if the distributor is in the correct position as you say, so post a photo. Also state the position of the #1 wire in the cap terminal. The OE '64 cam sprocket was cast iron. The nylon tooth sprocket didn't come along until '65. Of course I have idea what type of timing chain set is currently installed.

Duke