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Old 12-03-2010, 10:23 PM
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4x4_Welder 4x4_Welder is offline
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Join Date: Dec 2009
Location: Poulsbo, WA
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Quote:
Originally Posted by franklynb View Post
In particular I'd like to see an approach to measuring cylinder wear that's more technical/accurate
than "the cylinder isn't scored and looks round".

The tolerances would imply the use of a custom bore gage to "get it right". And
measuring taper in a deep hole ain't the easiest thing to do.

So, take lots of pictures, and explain your method! Cylinder fitment is key to good
power, especially on a N/A diesel.

--frankb
As mentioned, telescoping bore gauges, AKA T gauge or snap gauge. Set it, pull it out and measure with a micrometer or a good set of calipers.
FWIW, the 617 isn't a deep bore. When I rebuilt my Ford 300-6 (the third or fourth one I've done) I did four measurements per bore- Two 90 degrees apart at the top just below the ridge, and another two 90 degrees apart at the bottom of the wear area. Due to wear, I had to bore it to 4.080" and use .030" oversize pistons for a Ford 360, bumping my compression to 9.8:1, but that's a whole other story. That was a 3.98" stroke vs the 3.5" stroke of the 617, with a taller deck height as well. It was a little easier due to the larger bore, but I've measured out Subaru engines with an 82mm bore vs the 90mm bore of the 617.
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