Packard Forum Index » Pre-War (1899-1942)

Performed a dry and wet compression test on my Six with a pronounced smoky exhaust issue at the request of my mechanic. To my knowledge, the engine is the 4 liter inline flathead six. Dry test - cylinders 1-4 read 110psi, #5 reads 105psi, and #6 reads 80psi. The wet test on 5 and 6 gave me 110psi and 90psi, respectively. I would like to acquire piston rings, but have learned from experience that not all retailers know which parts are correct for this engine. Additionally, I purchased replacement spark plugs based on what the owner's manual (I have one that looks original, came with the car, on the front cover stating "For cars beginning engine B-1501") spec'd - AC-103 or Champion Y-4. Auto Zone had a "match" for the 103's in Autolite brand, but they physically would not screw into the spark plug holes in the engine block. I discovered the plugs that are in use are Champion UY-6. Which leads me to wonder several things; why the mismatch, is the engine perhaps not the original one, and will my search for piston rings, and other items I intend to acquire for a tune-up or repair, be influenced by this mystery. The engine serial/ID number is 23870A. Who is a reputable retailer to acquire piston rings and other perhaps Packard-specific repair and tune-up items from? Any insight would be much appreciated.

Before buying pistons you would need to ascertain whether the engine has been rebuilt in the past and possibly rebored so that you know what size to get. As for source, I have Egge in my 1954 Patrician along with their pistons but those were put in decades ago.

Has this engine run much in recent times? That compression doesn't sound too bad. Is the gasoline fresh?

I agree compression is not that bad, but I suspect this is a clear indication of a valve issue not a ring issue. These engines required a valve job as a regular maintenance issue back in the day. This was due mostly to the quality of the gas available then. Egge can provide rings but it would be necessary to know what engine you have first. A routine valve job is not a big deal and you could do it yourself if you have some mechanical skills.

Thanks to all for the insights. The gas is fresh, on my third fill (non-ethanol premium with a lead-substitute added by me) since acquiring the car in July. Suspect the car sat for some time at Burnyzz's in Ocala, Florida, before it's transport to Oregon. My mechanic is willing to work on it, next year, (he is very good, and so is very much in demand) if parts are available (a task he has given to me), which seems to be the rub, as ID'ing the engine with any precision is proving difficult.

Perhaps I missed the post where you described it, but what's exactly wrong that you're trying to solve?

Running rough? Driving user load issue? Idle issue?