360 engine machining specifications

[dwhip361]

Hey everyone , I'm looking for the engine specs for allowable cylinder taper and out of round so I can tell if boring is necessary or if I can just hone the cylinders . Thanks , Dave

 

[nm9stheham]

1965 FSM service limits for all engines was .005" out-of-round and .010" taper. But I guarantee you won't want to run these numbers; that much out-of-round will give you marginal to poor ring sealing, and that much taper will very rapidly wear out the rings. If you are thinking about reusing pistons, you first need to check the ring side clearance (land clearance) too; this parameter is very critical for good ring seal. The top rings and grooves typically wears the worst.

I personally would limit taper to .002-.003" max and out of round to about the same for a mild street use engine. Otherwise, bore. YMMV....

 

[dwhip361]

1965 FSM service limits for all engines was .005" out-of-round and .010" taper. But I guarantee you won't want to run these numbers; that much out-of-round will give you marginal to poor ring sealing, and that much taper will very rapidly wear out the rings. If you are thinking about reusing pistons, you first need to check the ring side clearance (land clearance) too; this parameter is very critical for good ring seal. The top rings and grooves typically wears the worst.

I personally would limit taper to .002-.003" max and out of round to about the same for a mild street use engine. Otherwise, bore. YMMV....

Thanks for the help . Dave