In reading Colvin's Corvette by the Numbers book, I've been intrigued by the camshaft profiles for the L78, L72, L71 & LS6. Can someone explain to me why the lift and duration were changed slightly in these years and what advantage might have been achieved or not by this.
In the L78, the lift was different for intake and exhaust respectively, .497 & .503, however the duration remained the same for intake and exhaust 348/348.
In the L72, the lift was the same for intake and exhaust, although higher at .520 & .520, however the duration remain the same, but lower for the intake and exhaust 336/336.
In the L71 & LS6, the lift was still .520 for both intake and exhaust, but now the duration was split for intake and exhaust, 316 & 302, respectively.
Of course on the L78,L72 & L71 we have about 11.0 to 1 compression, what does the 9.0 to 1 comp. ratio do to the LS6 in this circumstance? All the car magazines of the "era" say that the old '143' solid lifter cam was used in all these engines, but there are different part #'s as well as casting #'s, must be something going on here.
In the L78, the lift was different for intake and exhaust respectively, .497 & .503, however the duration remained the same for intake and exhaust 348/348.
In the L72, the lift was the same for intake and exhaust, although higher at .520 & .520, however the duration remain the same, but lower for the intake and exhaust 336/336.
In the L71 & LS6, the lift was still .520 for both intake and exhaust, but now the duration was split for intake and exhaust, 316 & 302, respectively.
Of course on the L78,L72 & L71 we have about 11.0 to 1 compression, what does the 9.0 to 1 comp. ratio do to the LS6 in this circumstance? All the car magazines of the "era" say that the old '143' solid lifter cam was used in all these engines, but there are different part #'s as well as casting #'s, must be something going on here.
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