Owen Posted June 25, 2002 Share Posted June 25, 2002 If I have a degree wheel and dial indicator, can I get the specs of a cam? From everything such as lift to duration to overlap? Thanks, Owen Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted June 26, 2002 Share Posted June 26, 2002 Not having actually done this, I think it should be possible to get close. Are you thinking of checking it in the car or on a bench? If in the car, it is going to be tricky to get accurate lift readings using lifters and extension rods and such. It would be better if you could pull the cam and put it on a surface plate with some V-blocks. Mathmatically, if you can accurately measure each lobe (intake and exhaust) in 5 degree increments (maybe closer around the opening ramps), the other parameters can be calculated. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted June 26, 2002 Share Posted June 26, 2002 If it is a stock cam, tell me the letter on the back and I will tell you the spec's tomorrow. Quote Link to comment Share on other sites More sharing options...
Owen Posted June 26, 2002 Author Share Posted June 26, 2002 It's a custom grind and I just wanted to double check the specs. If it's 440 lift, 208deg@0.050 and 112LSA, can I find out what overlap and intake centerline are? Thanks, Owen Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted June 26, 2002 Share Posted June 26, 2002 I think the LSA and the intake lobe centerline are the same. I think. You should be able to get overlap, but I am not real sure on that. Have you checked some of the cam makers websites to see if they have any tips on figuring that out? I know you can do it with a dial indicator, but have no idea how. Frankly, I shoot from the hip on cams. I don't like wide lobe centers, and like more lift and less duration. Quote Link to comment Share on other sites More sharing options...
Owen Posted June 26, 2002 Author Share Posted June 26, 2002 Haven't been able to find anything so far. I coulda sworn I had a magazine with this info but I can't find it.... Owen Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted June 27, 2002 Share Posted June 27, 2002 What you want to do is possible Owen. It will take careful measurements and lots of data points. When you are done you will plug the numbers into a spreadsheet and then create a graph with the crankshaft degrees on the X-axis and the lift on the Y-axis. Both the intake lobe data and the exhaust data will be on the same graph. Wherever the lift of the two valves overlaps on the graph, then you have your overlap. Where the lift is greatest on the intake lobe, that is the intake centerline. The difference between the centerline of the intake lobe and the centerline of the exhaust lobe is the lobe separation angle. The intake centerline (experessed in crankshaft degrees) is dependent upon how the cam is mounted in the motor. It can be advanced, straight up or retarded. The lobe separation angle is ground into the cam and is not adjustable by the installer. Quote Link to comment Share on other sites More sharing options...
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