Quote:
Originally Posted by dataway
I wonder how many HFT failures were using stock grind cams, or modern replicas of stock grind cams, as opposed to modern profile cams.
If you filter out high performance cams and high spring pressures I wonder what the failure rate would be.
I'm curious .... did high performance cams of 40 years ago use similar profiles to modern HFT cams, or are modern cams more abusive to the valve train?
|
There were failures long ago .... in 1983 i bought a 1970 espirit bird 350 4speed it ran ok but letting out the clutch i could feel a uneveness in the power did all the tune up stuff then got to watching rocker arms while running .... turned out the original 254 cam had 3 still operational but shaved lobes and concave lifters and the 254 cam has even less lift than std 4bbl cams
HP cams have had a sort of stepped evolution XE. was a step then a group before that and then 60s to early 80s time frame roughly each new generation has pushed lobe intensity higher in search of more overall torque and this stresses out the fragile lobe and lifter dance