bore/stroke (was Re: [T3] 74/78 crank?)

[Greg Merritt <gregm@vwtype3.org>]

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	So I went to a modern manufacturer's Web site and looked up 
specs on their 4-bangers.

	Standard model:  1.7L, 115hp @ 6100rpm, 75mm bore x 94.4mm stroke
	Sport model:     2.0L, 160hp @ 6500rpm, 86mm bore x 86mm stroke

No, I didn't reverse the bore and stroke numbers for the standard 
model!  Isn't this funny?  In the air cooled VW world, the tiny 75mm 
bore is smaller than used in a 40horse 1200cc VW engine, and the 
stroke is a super-duper mega-wild 94.4mm.

	Also, compared to modded VW engines, this modern 
manufacturer's (ok, it's Honda) sport model has a "small" bore (very 
close to the stock VW 1584cc's bore, half a mm off) and a fairly big 
stroke.  The numbers for bore and stroke happen to be equal, too -- 
don't people call this 1:1 ration a "square" engine or something?

	Ok, I also just checked VW's modern 2.0L specs -- 82.5mm 
bore, 92.8mm stroke.  Skinny and long, just like the Honda.

	What do the modern-day VW and Honda know that we don't?  Is 
the issue that the aircooled case just doesn't lend itself to long 
strokes, so people -- even when building a "stroker" motor -- end up 
favoring a relatively fat bore?  Could I even easily get the parts to 
build, say, 85.5mm pistons with an 86mm super-stroker crank, a lot 
like the Civic Si?  And, if I did, would it be a super-torquey, 
cool-running dream to drive?

-Greg

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