My 360 Magnum build thread

Took several more sets of measurements over the weekend, refining my process and accuracy potential, and now, finally, I can get consistent and repeatable measurements of each pistons' deck clearance within .0005"

I bought a digital dial indicator from harbor freight for $29. Re-mounted on my harbor freight magnetic base, squared up the rods and indicator, and took ALL play out of the setup. I also refined my procedure by rechecking zero after each measurement on a 3/4" sheet of glass that was lying around in the garage.

Obviously the last variable is the deck surface that I am mounting the magnetic base to and how consistent/square that is. Even though I standardized every other aspect of the process, this is the last variable (beside rod length and piston compression height) I have no control over at this point.

After repeated measurements that were all within .0005 I now feel confident in my ability to measure piston-to-deck clearance accurately, at least as accurate as the deck surface allows mounting of the magnetic base. Here are the latest and most accurate and repeatable measurements to date:
[FONT=Verdana, Helvetica, Arial]
1 .0040 (8 )----.0035/.0045
3 .0035---------.0030/.0045
5 .0035---------.0030/.0040
7 .0045 (T)-----.0045/.0045
2 .0050 (K)-----.0040/.0050
4 .0045---------.0040/.0055
6 .0070---------.0065/.0075
8 .0070 (A)-----.0065/.0070[/FONT]

These measurements are the result of multiple passes on each bank (minimum of 5) and then averaged together. The column on the right shows the lowest/highest per cylinder and the values in parenthesis are the rod markings, otherwise all rod/piston combos are in their correct bores.

Taking the averaging aspect one step farther, if I average each bank we see that 1-7 is on average .004 in the hole and 2-8 is .006 in the hole. The only reason this is vaguely important is that if the decks are relatively close to square already, which I doubt, and the minimum cut Kelly's can make is .005," then I know that some pistons may pop out of the bores by .001 or so, but until the decks are square and I mock it up and measure again this is all just hot air.

Next step will be taking the block in, next update after that, hopefully with pics of the square-decking process.