Leon Posted January 8, 2013 Share Posted January 8, 2013 Actually, a quick look in the EM section of the 1972 FSM shows valve lift for a twin-carb'd L24 to be 11mm (0.433"), FWIW. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 8, 2013 Share Posted January 8, 2013 73 shows 11 mm also. I've looked before and can't find the ZX (P79, P90) numbers in the FSM's, so can't compare those. Who knows from where the numbers came. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 9, 2013 Share Posted January 9, 2013 I'd like to measure my P90a M cam. I bet I get about the same valve lift. Quote Link to comment Share on other sites More sharing options...
Xnke Posted January 9, 2013 Share Posted January 9, 2013 It's actually the lowest valve lift of any of the cams I've measured. The P90 hydro cam (M stamp) I have in my bedroom works out to be .390" valve lift, including the rocker ratio of 1.48. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 9, 2013 Share Posted January 9, 2013 (edited) .390" = 9.9 mm. That's what the atlanticz table shows for exhaust valve lift for the J cam. You're actually measuring .4 mm over what's shown for the M cam. Odd. It's also odd that the part numbers both end in E4126 for the L24 and L28E A cams, in the table, and show the same specs, but the FSM numbers are different, 11 mm vs 10.5 mm. Maybe someone assumed that the A's were the same. Just goes back to verifying what you read. Maybe someone could start a "measure your valve lift" thread and get some more verified numbers. Just for fun. Edited January 9, 2013 by NewZed Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 15, 2013 Share Posted January 15, 2013 How was your experience with Delta Cam? I called him today and it's crazy inexpensive, about $100 to do the cam and rockers less shipping... Quote Link to comment Share on other sites More sharing options...
Xnke Posted January 15, 2013 Share Posted January 15, 2013 NewZed, the cams are probably the same...it's the rocker arms that changed. I have some here that are either ground funny or are made different...the same M stamp P90 cam measures out .390" to .393" with 5 sets of 12 arms, then I have two sets (from earlier engines, no less...one came from a 1970 and one from a 1972...all the rest of my rockers are 78-84) that with the same cam, in the same head, with the same valvetrain, show lift numbers of .384" to .385". I can't find any consistant indicator though, the only reason I know they all came from the same engines is that I kept them all on a string through the hole in the rocker post cup, and labelled. These are all the 2-piece arms, I don't have any of the real early single-piece forgings. Quote Link to comment Share on other sites More sharing options...
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