Early Piper DOHCBP270H  (higher lift but less duration)

in 11.48 20/60 (260°)
ex 11.18 58/18 (256°)

Later Piper DOHCBP270H (longer duration and less lift)

in 10.87 22/62 (264°)
ex 10.03 60/20 (260°)


Now the Piper DOHCBP285H cams

in 10.87 25/65 (270°)
ex 11.07 62/22 (268°)


Now I have spent over 15 years working in engineering so I'm fairly good at measureing stuff.
I have a digital vernier gauge and a full set of manual micrometer gauges (all calibrated).
My inlet cam is defo 10.87mm lift (I don't have the gear to measure the duration)
BUT!!!! the exhaust cam is defo 100% 11.07mm lift.

Both cams are stamped BP270 on the ends. My engine revs really well, well past the quoted 6200 rpm as stated in the Piper catalouge. I was thinking that maybe there was a mixup and I have 285 spec cams but stamped 270?

To recap they BOTH have the lift of the 285 cams they rev like the 285 cams, but are marked as 270 cams :? 


STD cam

in 11.10 13/51 (244°)
ex 10.90 43/16 (236°)