Packard Forum Index » V-8 (1955-56)

From some recent reading I have done, it seems that when Packard started design work on the V8, they started out with a design goal of 269 CID. It seems as the horse power wars started Packard then increased the engine size 303 CID, then to 333 CID. Thus as we all know ending with both a 320 and 352 CID engines for production in 1955.


John F. Shireman

I belive the Packard 352 was the largest cubic V8 engine of 1955. It was somewhat overshadowed by Chevy's introduction of their first V8.

From what I have read, the engine was 9 years in the making,
and was designed for future displacement growth in mind. Engineers claimed there were atleast 400 cubic inches possible, maybe more, as evidenced by the growth of the 1956 cubic inches.

Greetings,

The Packard V8 has a 5" bore spacing, the same as the 500" Cadillac. It would easily have grown to 500" and then some.

thnx, jack vines

The only thing i don't understand is why Packard did not leave some extra room for stroking growth. It looks like maybe that is what they had in mind if we consider the long gudgeon pin depth into the cylinder. BUT then they tightened up the crankcase real tight onto the crank and i'm not sure how much cam clearence there is for stroking if any.

At 352 cubes, even for 1955 the block and heads of the V8 are an albatrose in terms of size and weight. ALtho i like the Packard V8 engine it strikes me as something that was thrown together in 9 MONTHS, not 9 years. Something that only a group of very clever engineers could have pulled off.

FWIW, several Packards have been stroked to 3.75" and a few to 3.875" It does require grinding clearance notches to the bottoms of the cylinders.

It is pretty standard practice to modify the bottoms of the cylinders for a longer stroke. When Ford increased the stroke of the 289" to the 3" of the 302", they shortened the bottoms of the cylinders to clear.

IMHO, the small Packard engineering staff did a pretty good job man-for-man as compared with GMs thousands of engineers on the Chevrolet V8. It had as many teething problems in the first couple of years as did the Packard.

Another FWIW, the Packard V8 is tall and wide, but not as heavy as many make it out to be. Studebaker and the early Mopar hemis were the worst offender in terms of pounds-per-cubic-inch. The 374" Packard V8 weighs 705# ready to run, or 1.88#/cu.in. The Studebaker 289" weighs 695#, or 2.4#/cu.in. If one really wants to get porky, the Stude 224" and the Dodge 241" weigh 3.1#/cu.in

thnx, jack vines

Pardon my ignorance for a question. If the Stude 289 is 695# and the 374 is 705, then what is missing. In some of the car reports of the era, it was reported the Golden Hawk 56 being nose heavy vs 57 because of the engine. The 352 would be a few pounds more possibly and the 289 with supercharger would surely be about the same as the Packard so what causes the writers to review as they did.

I have a good deal of respect for Mr. Vines and I haven't checked out the weight of the Stude 289, but it couldn't weigh anywhere near the Packard V8. I doubt the 695 pound weight. ACOlds, can you shed some light on the weight of the Stude 289??
And the 56 GH was nose heavy. I drove one and damn near bought the farm on a sharp curve to the right. It liked to run straight ahead.

Hello Jack Vines! You seem to really know your stuff on the V8's. I'm new to the club, but old to owning Packards-30+ years and counting. I now have a 56 400 that currently is powered by a 55 320 and want to max-stroke a 374 to replace it. I am a skilled engine builder but don't know the crankcase limits or what crankshaft options are viable. I'm OK with any clearancing grinding but don't know about the cam or depth cylinders can be notched before hitting water jacket etc. Any Info. on the subject would be greatly appreciated.

The 374" block can be safely bored to 4.250". The standard cast steel crankshaft has hollow throws. If it is a street engine and not to be run hard, it can be welded and offset ground for another 1/4" of stroke. I don't recommend it.

There were a very few, very rare forged steel crankshafts made for service replacements. They have solid crankpins and can be welded and offset ground up to 3/8". Any of these stroker options will require clearance grinding of the bottom of the cylinders and relieving the bottom of the oil pan.

As to the weight of the Packard V8 versus the Studebaker V8; I weighed a 1956 Power Hawk 259" Studebaker V8, complete with bell housing, flywheel, clutch and a 1956 Golden Hawk 352" Packard V8 equipped the same way. They were weighed on the same scale hanging from a hoist on the same day.

Please go to the '56J site http://www.1956goldenhawk.com/ and read the '56J front end weight bunk article also, note the published shipping weights. The '56 Golden Hawk was only a few pounds heavier than a similar equipped '56 Sky Hawk or '57 Golden Hawk. There are two differences I have noted which make the '56J a bit more nose heavy. The Packard engine is longer and taller than the Stude and thus the weight sits slightly higher and farther forward. Many '56Js were also equipped with the Saginaw power steering, which adds another hundred pounds high and to the front.

I've owned and driven hard both the '56 Sky Hawk and Golden Hawk. The Golden Hawk will definitely accelerate faster, has a higher top speed and will keep up in the turns. Neither is a sports car, but both were the fastest cars of their day. The '56J with manual transmission was quicker and faster than the '56 Corvette and '56 Thunderbird. It was quicker and about even on the top end with the '56 Chrysler 300.

thnx, jack vines

Just out of curiosity, where does all of the weight in the 259 come from???? Bigger crank???? Is it an undersquare engine or what???