Riser Plate for Block

[Stuart Giles]

Jamie. Its not something I have done, but  was considering a block skim to restore the height of valve seats... 

This is something I have done quite a few times, seems pointless wasting  some of the valve lift with exhaust valves pocketed into the block. I've not always found it necessary to skim the piston crowns on A7 motors after doing this. When the pistons do need skimming I use this home made jig.





This  jig locates in the piston  ring lands and could be used on a lathe faceplate if a milling machine isn't available. The one here has done all sorts from small Jap bike pistons right up to American "big block" items. Do not be tempted to just put pistons in a lathe chuck as the skirt is likely to be squeezed out of shape at best, and may fly out of the chuck, bounce all round the workshop, and be transformed into a piece of mangled scrap metal as one of my brothers proved right in front of me whilst  "decking" a Ford 10 piston when I was a kid.