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

This question was posted by Forum member flyntgr in the Chat Room. Just promoting it to the appropriate Forum where it's much more likely to receive a response. I'll PM flyntgr to advise him his query is now in the Post War Forum

"I'm a newbie of 2-3 weeks joinder. Can anyone tell me about the issues involved in welding cracks in 1954 aluminum head for 359 engine? If it can be done successfully, can you refer me to an experienced Packard shop who is successful at it?"

I wouldn't recommend trying to repair it, it is by today's standard a fairly primitive aluminum alloy and if you manage to fix today's crack, you'll almost certainly get another failure down the road. Unless you're hell-bent on keeping it the best choice is to replace it with a cast iron head. The change will affect the compression ratio so you may have to change ignition timing and deal with some distributor advance curve changes but for reliability it's the way to go, sad to say.

If it was "1" crack you might have a chance with TIG, but soon as you say "CRACKS", it's probably fatigued/corroded beyond service life. Would have to clean and use die penetrant test on it, first, to see where and how bad it is. If localized, maybe able to machine bad parts of it out and make/weld new machine patches, but $$.
Just another sad fact of flat heads due to the stress distribution even though they're somewhat low compression. Same applies for cast iron ones. Nature doesn't like flat, it tries to bend it under load, so that cyclic bending stress adds up over time leading to cracks. Al thermally expands a bit more also than the cast so when you try to hold it down on tight to cast, you're adding to it. That was one of the crowning achievements of the "hemi" head. Mimics the natural shape.

I remember someone was thinking about producing new aluminum heads. Not sure if this project ever came to fruition?

packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=14370&forum=12

The cylinder head on my '54 Convertible rotted out around #1 cylinder back in the Spring of '06, allowing coolant to overrun the head gasket and into the cylinder. I took the head to an automotive machine shop that the dealership I worked for used. They told me that they did not weld aluminum but would send it out to be inspected and welded. They found more rot around one of the stud holes also. They welded it up, then the machine shop ground the weld back to original shape and checked the head for flatness. They charged me $225.00 for the work and it's been fine ever since. The machine shop and the unknown welder were not Packard shops per se, but the machine shop did and still does build racing engines along with their general automotive machining work.

You might want to have such a shop in your area look the head over and see what they think. If there are multiple cracks throughout the head I'm sure they'd tell you to get another head. I hope yours is also fixable; for some reason I just don't like the idea of a 327 head on a 359 block.

A good friend had his Aluminum '26 Marmon Trans case welded up in the car recently by an experienced aircraft repair guy. Saved a ton of cash & hours.
The key is likely finding the right guy.

Even if the cracks can be successfully welded this is not a repair without risks. It is possible the welding will result in some warpage of the head which might have already been a pre-existing problem. Generally aluminum heads of this length are surface-milled and not surface-ground as the aluminum tends to load the grinding wheel. And especially if the head had been surfaced in the past you have a risk of uneven compression chamber volumes (differences in CR) and even the risk of not having enough remaining clearance for the valves to open without hitting the head. Been there, speaking from experience here.

I wonder if there are enough senior 1954s out there to make a new head project worth the investment? I heard a while back that such a project was being contemplated but never heard more about it since.

A reproduction aluminum head could be used on any of the straight 8's? 288, 327 or 359?

John

The head on my 1954 Patrician was welded decades ago without problem but as I recall it was to fix corrosion under the steel outlet tube. After the welding, I simply milled it flat again. Putting steel together with aluminum, then adding water, is a sure way to create electrolysis so I wonder why an aluminum outlet wasn't also used.

However, now that the car has been sitting untouched for decades I see there is much corrosion on the head so it will likely have to be replaced and I would prefer to use the original aluminum head or an authentic reproduction. I don't want a finned racing head. An aluminum water outlet that looks like the original steel one would also be great.

The worst time I had getting an aluminum head from a 359 was caused by corrosion between the studs and head, in some cases filling the cavity between the stud and head with a solid mass or corrosion products. Were I do to another 359 head job (unlikely) I think I'd paint the stud shanks with shellac or similar to make life easier for the next guy.

ptv, a reproduction 359 head could not be used on ANY of the straight 8s, but is interchangeable with the 288 and 327 with just changes in compression ratio and cooling efficiency.