Packard Forum Index » Post-War (1946-54)

Good Afternoon...You could easily have the wrong spark plug for today's fuel. Look to see what plugs from other manufacturers will run a bit cooler. Perhaps give Ross Miller a call if he does not happen to see this post. 410-357-4561. Another Packard specialist is Custom Auto in Santa Ana, California. 714-543-2970. The owner, Robert Escalente, started there sweeping floors, many years ago. I'll bet if it's an odd problem, not well known...These guys will have the answer. Ernie in Arizona

I would want to establish TDC with certainty. Timing marks on dampers can shift. The position of the vacuum advance can vary somewhat, and it is not a reliable guide for timing. The distributor responds to engine speed and load, and it may be over-advancing the spark due to issues with the mechanical advance or a vacuum advance that is out of adjustment or improperly connected at the manifold end, or a stuck advance plate. Improper timing is the commonest cause of pinging, with an overly lean mixture being second. Older carburetors have mechanically operated metering rods. Newer ones may have metering rods operated by a vacuum piston and they have been known to stick.

Point gap affects timing.

53Cavalier, thanks again for your questions. What happened was that I hadn't been happy with the idle for several years but it wasn't bad enough to chase after. One day in October it suddenly wouldn't idle at all, stalled the instant I took my foot off the gas pedal. That had to be something in the carb idle circuit so I had the carb overhauled. I put it back on and it would idle but it was about the same as it was before. I decided to go after it. I checked for vacuum leaks that could be causing it to run lean, couldn't find any but the vacuum advance might have a pinhole so I replaced that. The advance Max sent was identical to the old one. I R&Rd the distributor to replace the advance and didn't see any evidence of worn bushings. After this is when I noticed the pinging. I had been thinking of putting a Pertronix system in for a couple of years so I did that, their Ignitor II module and the Flamethrower coil they recommend for the Ignitor II. The engine does start a lot faster than it did before but it still pinged. I contacted their technical support and they said there was no adjustment that could be made, look for a cause outside of their module. That's when I found that backing off the distributor position will stop the pinging but the idle quality and the vacuum gauge reading suffer. As to a problem with the mechanical advance, if the weights were stuck in the full advance position wouldn't the pinging happen all the time and not just when under load? I agree that this most likely is a timing problem and I just need to find that sweet spot where the pinging stops and the idle is smoother.

56Clippers, thanks for that question. I don't have an exhaust gas analyzer so this hasn't been done. I can say that I don't see any smoke coming out of the tailpipe.

Thanks, Ernie for your suggestions. Maybe I should check other manufacturers to see if they make a colder plug. I've watched Ross's video several times on timing the '51 through '54 eights. Since I have no pointer I used his trick of putting a coin over #1 spark plug hole when cranking the engine. He said to use a penny but I found that that jumps every time the piston is on the upswing. A nickel worked better for me, it would move a little whenever the piston was coming up, but when it was on the compression stroke the nickel would flip up a couple of inches into the air. When this happened the rotor was right at the #1 terminal on the cap. So I'm confident timing is close even without the pointer.

Thanks, 53 Cavalier for your further comments. The missing pointer is certainly an annoyance. I looked into these pointers. I thought maybe I could make one out of a piece of wire that would loop around the timing cover bolt, but looking at pictures of them the actual pointer is offset from where it fastens to the bolt. A further complication is I can't even see or reach the bolt that it fastens to. It looks like at least the radiator would have to come out as well as the auxiliary pusher cooling fan that I installed in front of the radiator and who knows what else, just to put the pointer on. That's a can of worms I'd rather not open if there's another way to do it.

Maybe you can figure out another way to do a temp pointer. I can understand not wanting to pull your car apart to put a pointer on! I'll have a look at my car tomorrow, you should be able to rig something up. My thought is still that checking the timing with a light is a good/important next step.

As I recall, the pointer goes under two of the bolts for the front cover (I believe they are special bolts with a threaded stud on the head-side too and act as standoffs) and should not require moving the radiator to attach it but you may have to remove the generator to gain better access. It and the bolts should be very easy parts to find but be sure it’s for your engine in case there are differences between them (although the parts book should clear that up).

I suspect the pinging is timing related. I suspect the idle issue is not directly related to timing, and may be related to a vacuum leak. You need to establish with certainty where TDC is. Your car may have timing marks on the flywheel. If not, you can put # 1 cylinder on TDC and make some kind of mark on the crank pulley to indicate 0 degrees, if one is not already there, or if it is out of sync with the position of the # 1 piston.

Is the car hard to start when the engine is warmed up? Improper (over-advanced) initial timing can mimic a dragging starter, especially when the engine is warm.

As for a lean mixture, adjusting the idle mixture screws will have little effect on the fuel/air mix except at idle.