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Or was the bore different for bigger or smaller engines?

Supposedly the V-8 was designed to go up to 440 cubic inshes... Again, could a current engine be bored for this or would a somewhat different casting be required?

There were three different castings for the three sizes as evidenced by the casting numbers.

With so many of the parts interchangeable between engines, whether the different castings was only to ease machining or whether the smallest could be bored out that large is a good question.

320, 352 & 374 all had the same stroke, the only diff is the bore. A 352 can safely be bored 1/8IN to 374. I doubt a 320 could be bored more than 1/8IN, so that would be 341 CID.

My guess on the 440CID would be 4.185IN bore and 4.000 stroke.

Craig

Engine designers want a certain thickness of cylinder wall. They accomplish this at the foundry by having different cores depending on the final product desired. The sand cores create the internal water passageways and determine the wall thickness of the cylinder. It would be impractical to try to bore a 320 out to a 374 as there is probably not enough material there to remove safely. If you ever get the chance to visit a foundry, take it and try to absorb as much as you can. I enjoyed the work there - it just didn't pay enough.

Aren't the external dimensions and bolt points on all the engines the same? If external dimensions are the same and they want a consistent wall thickness, would that mean the 320 with a small bore would have a huge water jacket or would they have done something else? I don't see an obvious external difference but if there is, where or what changes to make the engines swappable model to model.

I believe that all Packard V8s are externally the same. The bolt holes, etc all line up. The difference is in the cylinder wall thickness but that is an internal dimension. You could stick a 320 block in a 56 Caribbean and no one could tell from a cursory examination.

randy berger Quote:

Except for the engine color, of course. But, I'm sure you meant if were also painted ivory or bronze (depending on year) instead of red.

Craig

Hi Randy

Thanks for the explanation of different cores during casting to accomodate various bores. That makes sense in engine blocks of identical overall dimension, the most cost-affective way to do it.

Now, when it comes to different strokes in engine blocks of identical overall dimensions, are there casting differences internally to accomodate that change? I'm thinking of the 288/327/359 stroke differences.

Steve