Packard Forum Index » Project Blogs

the price is right on - glad to see that they are line boring it. My shop couldn't do that - hope it doesn't come back to bit me in a few years.

I don't recommend drilling and tapping the head for 14mm plugs. Reason being that you will not get good thread length as the 10mm plugs had a very short thread length. The 14 mm plugs will then stick through the head too far and be in danger of being struck by the exhaust valve. Of course you can fix that with a thick copper washer under the plug but that is a bit cheesy for a racing engine.

A good bet is to find the latest head you can find as Packard finessed the combustion chambers year by year for flow and turbulence. The 54s are different than 53s, even tho rated for the same compression on the 327s.

The 14 mm conversion is more or less non-negotiable. Considering the race happens in the middle of nowhere, I have to make the car accept commonly available replacement parts. Keeping the 327 is what makes the car unique, but it will also be the primary weakness, so I have to upgrade it to live in the modern world as much as possible. Using modern plugs also means more reliable spark.

Speaking of which, who's got suggestions on upgrading the oil pump and pickup? From what I understand the oiling system is one of the primary weaknesses of this design.

I'm not aware of any "weakness" in the oiling system of this style engine and can't even recall ever hearing a discussion about it. Do you have some reference for that concern?

I agree entirely with Ross about the 10mm to 14mm plug conversion. I know it was done rather commonly in the day, but the web thickness where the plug threads are is thinner for the 10mm plugs so not only is there the risk Ross speaks of, but also the protruding threads can accumulate carbon and be difficult to remove, not to mention less thread contact area to secure the plug. It's water of the dam now, but I think a better solution would have been to just carry some extra 10mm plugs in the car. Perhaps you might just keep you eye out for a suitable head with 14mm plugs, the changeover from 10mm to 14mm occured during (late in) the 23rd series model run.

Potentially, at the same time, this will be a semi-spare head come race time. I'm getting a 288 head for the higher-compression ratio. I guess I'll see if i'm happy with the result from this conversion. By the way the cup is caste now, drilling and tapping will probably result in an extra course of threads compared to the 10mm.

There's always the option of adding material via heliarc the re-drilling and tapping.

My point was that all of the later heads already have the 14mm plugs and do not need that remachining. Also I have never encountered any oiling problems with these engines.

I caught your point Ross, but like you said, kind of water under the bridge. The cylinder pressures are so low though that I'm not super worried. If it was an 11:1 or 12:1 compression ratio or supercharged it would be one thing, but around 7-7.8:1 I cannot imagine the thread or plug failing.

There are plenty of these heads around though, so I'm not terribly worried about getting a replacement if I need to.

Sweet Mother of God, the carb was filthy! Every time I take something on this car apart I can't believe I drove it home, that it was smooth as silk, and that it kept up with modern traffic.

Gallery:http://imgur.com/a/JrPj2#0

Ran across this fascinating video from the 1950 Carrera with some short bits of bathtub Packards careening about. Original private footage gives a nice feel of what it was like.http://youtu.be/sXk1jQU7Kxg

Interesting film, but not too encouraging. Many Packards can be seen broken down alongside the road, and the comment at 9:14 referring to the contingency of Packards from the local dealership with "uno, dos, tres" on the sides, "they didn't stand up."

Attach file:

---

  (42.03 KB)