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Barry_R · #12 (**permalink**) 02-22-2011, 01:41 AM

Reading Rick's stuff makes my head hurt - even when I agree with some of his writing. I am going to buy him a paragraph key for his computer....they gotta make those somewhere...

Anyhow. Breaking rocker shafts is pretty common as Excalibur noted. It always happens where the end bolt goes through because it's the weakest spot. Factory 427s have steel stands which add support - so Ford was aware of the weakness of the design even 45 years ago.

End stands are similar to the normal ones in his picture, except that they are "U" shaped - having an added piece that wraps around the end of the shaft giving additional support. You can still break a shaft with end stands - but you need to try a lot harder.

http://ep.yimg.com/ca/I/yhst-4987827...2_2137_1291526

Stands are not really adjustable per se, but they should be checked during installation to be certain that they are all level and touching the head before being torqued down. I have seen bent shafts (not broken yet...) and mis-machined parts cause problems. I have also seen and experienced using fasteners that were too long, bottoming out in the hole before reaching full torque. I really prefer mounting studs for that reason.

Cam bearings are never "pinned" in an iron block - not sure where that came from, but doing so in an aluminum block is a good idea. I have used oversize cam bearings before - using the cam bearing set for a Genesis block in positions 2 through 5. The aftermarket Genesis 427 block has all five cam bearings the same outside diameter, as oppposed to the factory block where bearings are smaller in diameter going from front to back.

I don't subscridbe to the bazillion pounds of oil pressure, magic additive and submerge the heads deal - that's where Rick and I part ways. That's OK - we all have opinions. Your 65 pounds hot seems just fine to me - I'd like to see a little more at higher speeds, but that oil pressure ain't causing the rocker shaft breakage. A Chrysler oil filter is shorter or a Ford F700 truck oil filter is longer - one of those might help your installation issue.

Odds are that the shaft simply broke from fatigue. Lots of mile driven causing it to flex and work harden. A simple replacement might last another 20 years, although I'd add the end stands myself.