A few thing we've discovered over the years. The forged rockers with chrome faces offered the most strength and longest service life at a much lighter overall weight.
Porsche abandoned them early on because they were quite expensive and caused catastrophic failure with that all too common "money shift".
Cams and rocker used in the later engines 66-83 or so, were both fairly generic cold castings, similar material running in contact with each other lubricated by a spray of oil.
In or about 84 the rockers were redesigned to a heavier configuration and I believe a lower quality metallurgy.
Before 84, we rarely saw rocker wear without an oiling issue. This is also the time we started seeing the "Green Idiots" removing lubricating compounds from engine oil.
Cam lobe failures were relatively rare until people started chasing huge horse power. Higher lift meant increased friction and from higher load rates.
Although welded cams have been a common modification on high performance cams, this process started having undeserved negative reputation.
Moving to more modern times, we start seeing billet cams flood the market. Although China would seem to be the likely culprit, most new billets are actually cold cast in Turkey.
Given the great collector value of the older cars, more and more are being restored.
That means more and more companies are looking to cash in on after market parts.
Some very good and some just plain horrible. Poorly designed with low quality metallurgy.
That is what we are seeing in the rocker market.
While other are experimenting with "new " rockers we are rebuilding our cast rockers to a higher standard than even the Porsche factory specs.
For those of you who like the early forged rockers (money shift and all) we have taken them to the next level. We bore them for out proprietary DP4 bushing, regrind them to the proper radius, re-chrome them and finish with a dry film coating on the pad.
Thousands in use and no complaints "YET". 3-2-1
