Clocks and Springs and Carbs

[Lee B.]

Late 1967 Convertible 327/300 4-speed with A/C
3 Questions:
1. My aunt was in car and tried to adjust the clock and pilled the adjuster right out of the clock. Is there a way to reattach it without taking the clock out (i.e. glue it back in place)?
2. Are the springs different for a 1967 convertible small block with A/C than one without?
3. I have set my timing to 36 total, 14 static, and the vacuum advance brings in 12. I set my carb air fuel adjusters to where the vacuum gage says I get the most vacuum. The car runs great for 20 minutes or so and then when I get on it, it stumbles as the rpm's get above about 2500. As long as I drive it sensibly, it drives fine. What do I need to do to get this car running right? I know that is a big question, but any help is appreciated.
Thanks
Lee

[Ed S.]

Re: Clocks and Springs and Carbs

Lee,
I don't have an answer to your questions but while I am sure your aunt is a very nice lady, I do not recommend that you let her adjust your ignition timing or your carburetor. I'm sure others will provide more relevant technical advice. Good luck.

[Joe L.]

Re: Clocks and Springs and Carbs

Late 1967 Convertible 327/300 4-speed with A/C
3 Questions:
1. My aunt was in car and tried to adjust the clock and pilled the adjuster right out of the clock. Is there a way to reattach it without taking the clock out (i.e. glue it back in place)?
2. Are the springs different for a 1967 convertible small block with A/C than one without?
3. I have set my timing to 36 total, 14 static, and the vacuum advance brings in 12. I set my carb air fuel adjusters to where the vacuum gage says I get the most vacuum. The car runs great for 20 minutes or so and then when I get on it, it stumbles as the rpm's get above about 2500. As long as I drive it sensibly, it drives fine. What do I need to do to get this car running right? I know that is a big question, but any help is appreciated.
Thanks
Lee

Lee------

The front and rear springs for a 1967 small block were the same with or without C-60.

[Dennis O.]

Re: Clocks and Springs and Carbs

The same thing happened with my '67 clock. I tried to fix it a couple of times (super glue, JB Weld) and had no luck. You might be able to make it work by enlarging the hole in the clock lens so you can get more glue in there, but that's not a viable option for me. I have a battery shut-off switch on the car, and can now set the clock twice a day (I set the alarm on my cell phone for 5 minutes before what the clock says).

As to the stumble; do you have the gasket between the air cleaner and the air horn? Mine was missing, and I had the same problem.

[Jimmy P.]

Re: Clocks and Springs and Carbs

If the inner workings of he 67 clock are the same as the C3s you will need to take the clock out to fix it. There is a small brass gear at the end of the adjusting rod. There is also a very small spring on the rod. When you pull back on it to adjust the clock the spring retracts so the small gear can mesh with another main adjusting gear to turn the hands in either direction. Then when you let go the spring raises the adjusting gear up away. There is a small notch (groove) on the end of the rod that holds the brass gear in place. When your aunt pulled on the adjusting rod, she pulled the gear and spring off. They will be inside the clock. If the gear cracked it will not stay on the rod when you pull it to adjust the time. You will need to take the clock apart to get to these pieces. I had an extra clock that came in a box with extra parts with my 73, when I took it apart to see why I couldn't set the time I found what I just described to you as the problem. The small (very small) brass gear had just a hairline crack in it and every time I pulled the rod to set the time it pulled off. I did get super glue to finally hold it in place, not sure how long it will last. Hope this explanation was helpful. You'll probably need to send it out to get repaired if you don't want to try to fix it yourself..

[Frank D.]

Re: Clocks and Springs and Carbs

An off-idle stumble at WOT on a warmed up car can be several things (ignition or carb related) - what kind of carb are you running...?

[Lee B.]

Re: Clocks and Springs and Carbs

I am running the original Holley 3810 that was rebuilt by Eric Jackson.

[Timothy B.]

Re: Clocks and Springs and Carbs

Lee,

Many times problems that seem carburetor related are actually ignition related. How old are the spark plugs and wires, if the mixer was professionally rebuilt I would start elsewhere.

Does this 300hp engine have it's original camshaft. What is the advance curve because the original slow curve is 6* initial and 30 centrifugal all in at something like 5000 rpm but what you describe sounds good to me.

[Jim D.]

Re: Clocks and Springs and Carbs

Many times problems that seem carburetor related are actually ignition related.

An old friend in the auto parts business for many decades once told me "half of the carb. rebuild kits we sell are because of a bad coil". Since the O.P.'s problem starts after 20 mins. and everything is warmed up, that's where I would start.

[Gerard F.]

Re: Clocks and Springs and Carbs

Lee, Tim,

That 14d "static" does not sound right to me. Is that "initial" without vacuum advance. If the distributor is equivalent to the original for a 327/300 (like mine) the centrifugal advance should be 30 d all in. With 6d initial and 30d centrifugal, you should have 36d all in without vacuum. With a 15d vacuum you should be looking at 51d all in with vacuum, under no load. At idle with high vacuum you should be running about 21d with a 15d vacuum can.

I recently timed my 67 327/300/3.08 to 6d initial, 36d total without vacuum (all in @3000 rpm) for a 2800 mile trip California to Denver.
With a 16d vacuum can, I was getting 52d advance under no load (just cruising). Not a stumble on the trip, and did 16.5 mpg average for a trip with a lot of high elevation, mountain driving at 65-80 mph. Going across a high desert with 100d weather with the Vintage Air blasting, the 327/300 ran as cool as a cucumber.

Lee, maybe your timing is off. Perhaps the centrifugal is not right under load at 2500.

[Lee B.]

Re: Clocks and Springs and Carbs

Just tried retarding the timing to 6d. The car will not run. Runs okay a 10d. At idle the vacuum brings it to 22. Biggest improvement was a new coil. Got rained out. Will try a long drive tomorrow to see if the coil was the problem.

[Lee B.]

Re: Clocks and Springs and Carbs

On the clock issue, do I have to remove the dash to get the clock out or can you get it out by taking the panels off on either side of the dash?

[Gerard F.]

Re: Clocks and Springs and Carbs

Lee,

To remove the clock you just have to take the passenger side radio side panel off. Then reach in over the radio and slide off two clips that hold the clock in and remove the wiring connectors.

Pretty easy. (if you have eyes on your fingers)

[Lee B.]

Re: Clocks and Springs and Carbs

Thank you. Exactly what I was looking for.

[Duke W.]

Re: Clocks and Springs and Carbs

As stated by others your spark advance map doesn't sound anywhere close to OE, and what about the camshaft?

You need to use a dial back timing light to record and report the centrifugal curve. Also, what is the number stamped on the VAC? Does it hold vacuum?

The engine should idle very smooth at 450-500 with the AC compressor engaged at high manifold vacuum. You apparently have a vacuum gage, but did not report idle speed @ "Hg. What is it?

Without some basic test data all anyone can do is just guess.

Take off the cap and rotor, snap a photo of the centrifugal mechanism and post it. That might offer a clue.

Gerry has his spark advance pretty much optimized - 30 centrifugal all in by 3000, a 16 deg. VAC (correct for manuals, but PG should use a 12). The only thing I'd recommend is another couple degrees initial to bring the total WOT advance to 38, which dyno testing has proved to be optimal.

Duke