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

Dave, see my PS above.

356:
#1-1.34375"
#2-1.1875"
#3-1.1875"
#4-1.1875"
#5-1.6875"
#6-1.1875"
#7-1.1875"
#8-1.1875"
#9-2.09375"

Total length: 12.25"

I don't have the length specs for the later 9 main engines, just the diameters, which are the same for mains and rods on both styles of engines.

I believe the main bearing specs for the 359 are in the specifications, the first service letter. I have it upstairs and will check later this evening.

PS, yes the bearing widths for the 359 are given inthe 1954 specifications, my copy isn't legible enough to read but I believe there is a good copy available right here on this website.

Kev - you probably have a good crisp copy of the 1954 specifications, could you add up the lengths of the 9 mains on the 5406 engine?

Am not sure the one posted is very good blown up so here is a crisp one. You guys can do the math.

Attach file:

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  (15.20 KB)

Are the counterweights lead or cast iron???

Thanks HH56, did I add correctly, 1 inch less main bearing length on the 359 engine? that would be 1/8 inch per rod throw.

Are the counterweights lead or cast iron???

Forged steel. Lead, are you kidding me again?

Ok, that makes

#1-1.21875"
#2-1.0625"
#3-1.0625"
#4-1.0625"
#5-1.59375"
#6-1.0625"
#7-1.0625"
#8-1.0625"
#9-2.0625"

So that is 11.25", one inch shorter than the 356.

Keith, the counterweights are steel, like the crank.

Now another question on my mind is, did any other manufacturer use a 9 main crankshaft?

Sure, lots of Classic-era makers used a 9-main crank. Chrysler's and Pierce-Arrow's 385 engines come to mind immediately, also I believe the big Nash series of 1931-34.

Also the Chrysler 323 engine, the Pierce 366 engine, and a few others. Not sure about Duesenberg but there are others too.

Ok, just wondering. My main "specialty" is Packard and Hudson, don't know much about the off-breed stuff.

So, back to the subject at hand. Since my engine's assembled and I don't have any way to get the crank out to measure it right now, I'm presuming that since the cranks should be the same length, and everything else being considered, that since the mains are "longer" so to speak, that the counterweights are wider on the 356 as compared to the 359? If so, I would also presume that this was done because of the long rods and therefore more weight as compared to the 327/359 engines. Since the counterweights are wider, this would explain the need to make them removable. The extra width wouldn't matter to the rod, as the rod itself is narrower through the length compared to the rod journal. Am I getting the "gist" of it all?

Boy, I never thought this topic would occupy half my evening! I really thought most everyone except the V8 crowd would have known about the counterweight issue on the 320, 385 and 356 engines. Fortunately Nebraska is clobbering Arizona so I don't have to pay that much attention.

If what you're saying is that since more counterweight was needed and since the weights couldn't be larger in diameter because of clearance issues to the block, the only choice was to make them wider, then I guess I agree. Without getting into all kinds of stuff I don't understand too well like piston weight, big and small end rod weights, etc., I can't comment on why larger weights were required.

I need a break from this topic for tonight. I'll see what develops tomorrow.

PS - without bothering to look it up, the 356 stroke was 4-5/8, that couldn't have been much more than the 359 as the bores only differed by 1/16th.