Quote:
Originally posted by cstreit
There is no documentation in the technical manuals about deck height at all... nor in BA's book. Hmmm
Well I'm digging around in the factory manuals and have noticed that acceptable rod variance is .002" between centers... THis being the case, one could expect to see variance in the deck height by this much, in fact if ajoining rods where + and - .002" (.05mm) you could see variance up to .004" (.10mm)
They also list acceptable cylinder height groups. Each group lists acceptable standard cylinder install height as a variance of .025mm (.00098" or .001" rounded) meaning the cylinders within a group can also vary by a thousandth... Add this in to the rod measurement and you see a total DECK HEIGHT variance of .0025" on a single cylinder and .005" (!!!) between adjoining cylinders.
Since the factory only offers cylinder shims in incremental sizes of .25mm that do not account for variance in the rod dimensions this MUST then be acceptable.
What would concern me is if the variance was due to varying cylinders (not likely) or varying case dimensions, so I should not only check the case spigots, but also the cylinder heights, those two would be the show stoppers!
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I am a little out of place here on this board as I am not building a flat six right now, but in this circumstance, I believe a method to deal with the problem mentioned is to move parts around the engine until you have the optimum set up. On a 4-cyl motor I built, I had a similar problem and combined parts until they matched up. I mocked up the motor 3-4 times until I finally had to just work on one cly to get it the same as the other three. After all was decked correctly, I sent it all out for balancing. People have been mating the long rod with the high wrist pin for a long time before us.
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