Packard Forum Index » V-8 (1955-56)

If you spend too much time on this site, you may recall that I have been having what appeared to be cooling issues on my 5682.

It now appears that the cooling issues are in the past, but some adjustment is needed for dwell and timing.

In the manual under specifications, timing is listed at 10 degrees BTDC, but in a service adviser engines before D-1834 should remain at 5 degrees.

Can anyone explain the why? If the distributor was improved/changed how do I tell which I know have? Or can the mechanic divine timing on his own?

According to SC 29-5, "the engine plant stamps a number on a milled boss at the right rear corner of the right cylinder bank. these numbers can be seen by looking upward at the boss, which is in back of the exhaust manifold." Would it be easier to pull the engine, or can this wretched number actually be read in situ?

Puzzled here.....

And to add to the confusion, bulletin 56T-14 changed some of the specs again.https://www.packardinfo.com/xoops/html/downloads/STB/56T-14.pdf andhttps://www.packardinfo.com/xoops/html/downloads/STB/56T-17.pdf

You can tell which is applicable on your car by having the mechanic find the distributor number stamped on the plate and then go with whichever specs might be applicable -- original or one of the revisions.

The Utica number on the engine is a royal pain but here is a photo showing the actual location. With the heater so close, I don't know whether from above with help of a mirror or from below is easier.

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Since the engine number is related to the car serial number, can the engine number be deduced, divined or extrapolated from the car number?

How?

Oh what a tangled web we snare
When all we want is to repair

The engines and the pump fuel has changed so much since 1956, the specs no longer apply directly.

I'd set it at 10 degrees and listen for ping. If a keen ear can't hear any rattle in a long pull up a steep hill on a hot day, leave it there.

If ping is present, try 7 degrees and then 5, until ping is gone.

jack vines

Let me add my two cents worth. Firstly the engine number. With my car the engine number is exactly the same as the body number stamped on the door placard. Secondly, timing. I have a Pertronix kit fitted and started out with the timing at 10.5 degrees, backed it off to 10 and am about to go to 9.5 as I've heard some very occasional pinging, which suggests that it's not far off the right spot. At 10, I can drive for ages without hearing any pinging at all but, as I said, occasionally it happens. Perhaps of interest to us aussies, if I am to hear any pinging it's more likely to occur when I've had to put Shell petrol in the tank. Over here we have three basic grades of petrol - one standard and two premium, and I think the RON octane ratings are 91, 95 and 98. I usually use the mid range 95 as the car seems happy on it, and she seems to have a particular preference for BP. Cheers, John

JP, just to clarity with regard to engine numbers. There are two, the "motor number" which should match the vehicle number, and the Utica Plant number. The Utica number is sequential for the particular engine type (the prefix letter) and then numbered sequentially. The service bulletins and counselors which refer to running changes in the engine use the Utica numbers to show at which number certain change were made; of course the motor numbers can't be used for that purpose and the finished engines weren't necessarily installed in the same order that they were produced.

As noted, the very best method for timing correctly is the "by ear" method finding that point at which "ping" is barely noticeable under hard acceleration with a hot engine. Doing it this manner eliminates the issues of changes in compression ratio from prior engine rebuilding (decking, head resurfacing), gasoline brands and octanes, spark plug choices, etc. My 56 Carib does not tolerate 93 octane premium with timing at 10 degrees but gives good performance with no excessive ping at about 7 degrees. It would be unrealistic to find a single timing which is best for all engines even of the same type

Thanks OD, I wasn't aware of that. The number I was referring to is the number that is stamped at the front of the engine near the water pump. When I get a chance I'll see if I can identify the Utica Plant number. Cheers, JP

See this
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=2789&forum=14&post_id=28980#forumpost28980

i also have a petronix in my 55 with 374 pistons and a custom cam grind and valve springs. My dad and I could only get it to run really nicely at about 9-10 when the book was trying to say 6. i finally did get it to 6 and would idle, but it isn't very happy. i plan to go back to 9-10 and start from there when i am finally able to drive the thing.

Something new and different....

Duane came over today with an electronic setup to get this timing business cleared up for once and for all.

Ha!

I'll spare you the dramatic buildup; the issue now is that the centrifugal advance isn't working.

How would you proceed? Are there any parts available?

Max lists new bushings, which seem like a useable idea that is worth doing while we are at it.

Or would you send the unit to advance (or someone else????) and have the deluxe rebuild?

Then what?

This saga will be a chapter in my book.....