I agree with you Flat Ram, I cannot figure out why Chrysler made so many variations when just a few would have done just as well.
About all I can say is that it allows a person to mix and match to build something to suit the need. I am amazed that these engines had such rod length variations, a rod for each stroke variant. It would have been much cheaper to vary the piston's compression height to accomodate a +/- in stroke. Yet, for each bore series, you have only one piston of the same compression height - regardless of stroke, @1.978" from the wrist pin center.
I have never seen a canadian block, nor heard of one besides the truck book. I suspect them to be long blocks with thicker sleeves/cylinder walls than the US counterparts. The strokes of the Canadian and US long blocks look suspiciously similiar to me.
And I also agree, that really only four of these variations represent the majority of concerns to us, whether restoration or hot rodding a bit. The 217/230 short blocks and the 251/265 long blocks. The resulting differences in crankpin diameter in these two engine series are the source of my glee in concocting hop ups.
Its just nice to know, that within a particular series, a person can up the torque output over the range of the engine by swapping rods from lesser stroked engines.
Lets add a little more confusion to the mix, if that's possible. I was just cruising the Silvolite piston website, Chysler OEM in the 50's, and found a little morsel. Going back to Frank's mention of offsetting the wrist pin, the Slant 226 piston is listed as being slightly offset. The 226 slant piston is 3.400 bore, 1.740 comp height, and available up to .060 overbore. The amount of offset is not listed, just mentions "offset". It may be possible to set up a flathead engine combination that uses the best bore, rod, stroke combination and utilize this piston as an "off the shelf" component. A person could at least utilize a 251 rod length on a 265/4.750 stroke and get the advantage of a longer rod and a little wrist pin offset. By the way, a 226 piston will fit the 3.375 bore as the difference in fit is only .025".
The Silvolite link to chrysler 6 pistons:
http://www.kb-silvolite.com/slvpg36.htm Hudson
[This message has been edited by Hudson (edited 08-30-2001).]
