4g61t.org

A friend of mine has an old set of HKS cams that do not have the duration stamped on them. The part number on the intake cam is M003 704 and the exhaust cam is M006 704(I am not sure about the "6", it is chewed up). When I whip out the 'ol micrometer I get 1.180" for the smallest dimension of the lobe and 1.413" for the largest dimension on the intake cam and 1.400" for the exhaust. Subtracting the two gives me lift values of 0.233" for the intake and 0.22" for the exhaust. These are no where near the 0.385" lift of an HKS 264 cam, but are more than stock.

Are these old re-grinds from HKS? Did HKS offer something less than a 264 back in the day? I cannot find any information about old HKS cams and HKS USA is out of business so there is no one to call. Hopefully someone on here knows something... Thanks guys.

Nevermind. Found the answer to my problem. All the companies measure the acutal distance the valve opens. The rocker acts as lever when opening the valve so you have take any measurements from the cam and multiply by 1.7 to find what the valve lift will be.