Do 5.3's have flat top pistons?
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I am trying to figure out the engine that I bought. It's either a 4.8 or 5.3. I was told that the 4.8's had dished pistons and the 5.3's were flat tops. Is this correct?
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If I remember correctly the 4.8's have flat tops and the 5.3's are dished. The stroke of the 4.8 is shorter, so the flat top pistons help keep the CR up. Both engines are 9.4:1 CR, and the bore is the same.
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From Handzel's book:
LR4 - 4.8 - 3.267" stroke
LM7 - 5.3 - 3.662" stroke
Both have 3.779" bore
LR4 is 9.47:1 CR
LM7 is 9.49:1
The book doesn't have any details on the pistons, but with the shorter stroke, the 4.8 has to have the flat pistons to keep the CR up.
LR4 - 4.8 - 3.267" stroke
LM7 - 5.3 - 3.662" stroke
Both have 3.779" bore
LR4 is 9.47:1 CR
LM7 is 9.49:1
The book doesn't have any details on the pistons, but with the shorter stroke, the 4.8 has to have the flat pistons to keep the CR up.