The push rod is "bent", not really "twisted" and not "bent" that bad. It did not gouge out the bottom of the rocker so I'm kind of puzzled over what caused it to bend. Pretty radical motor so I'm guessing the best quality push rod material. I think it was the really BIG clearance the rocker had AFTER the roller failed that caused the most damage.
However, in both cases (roller breaking and shaft cracking) I think this damage is a direct result of the .040 or greater tappet clearance the car was running when I got it. I think that BIG clearance set things up to "break".
I've got the motor torn down now, examining every part carefully. The block is a hydraulic lifter late model 427 side oiler block. It has a "restrictor" at the begining of the lifter
oil galley to limit
oil flow to the solid rockers. I suppose the restrictor would be removed if a guy was running hydraulic lifters. I suspect the roller lifters were getting plenty of
oil, but at 10 to 12,000 miles their "life" was up!
I'm looking into having the pistons milled (there pop-ups) flat to lower the compression. BUT, I'm not sure this will drop compression enough, so I may go with new "dished" pistons. 63 cc combustion chamber and current C.R. is 12.5 to 1. I would like to see 10.5, 11 max.
Also going with a "Level 5" Crower cam with a lower rpm range. 2500 to 6000 with a 7000 redline (but after 6000 the cam is "done"). This should bring the useable rpm of the engine in line with my rear gear and tire size to optimize cruising and low end torque. Dumping the BIG pressure valve springs and going with far less seat pressure springs.
The 660 center squiter drag racing carbs are out, 600 cfm dual Holley with vac secondaries are "in".
I figure horse power will drop from 667 to a mere 500 or so. But a much more "useable" 500!
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