Originally posted by CTX-SLPR
I'm going to agree with George here, they also say that all machine work should be done after the treatment. I'd do the parts individually and then check the tollerances afterwards because I have to disagree on the deminional shift, any time you change the temperature of a metal it changes size, some metals moe that others. When cryroing it the metals will shrink and relax the internal stress then when they are returned to room temp they will expand again and it is not garenteed that they will return to the percise orginal shape. I'd tear the engine down, cryro the crank, rods, cam, lifter, timing chain, pushrods, rocker shafts, valve springs and valves and leave the heads and block out. I'm not sure how this works on Aluminum so I'd do more research before trying it on pistons, rocker arms (unless they are steel), and the front cover, though I think it would likely help, but with Aluminum's greater coefficent of expansion I'd be leary about keeping tollerances and potential cracking in the complex passages of the front cover. Also shotpeen or tumble your valve springs before you cryro them, this will also help increase their fatique resistance.
more penny's for thoughts for me,