26-07-2018, 09:16 AM
Hi Simon
If the book you are alluding to is the once very popular The Sports Car by Campbell, at least in the 3rd Ed gives wrong formula for piston accel (and does not make clear the increase and decrease at top and bottom). And the chart of big end loads at firing at high rpm does not clearly distinguish net up (long stroke) from down.
On repeatable measurements, micrometers are a challenge. It is difficult to repeatedly acheive the claimed accuracy. The anvils have to be free of oil film. The oil film in the thread changes with repeated closures. The static setting differs from measurement of an object. Errrors accumulate when using separate internal and external.
If the book you are alluding to is the once very popular The Sports Car by Campbell, at least in the 3rd Ed gives wrong formula for piston accel (and does not make clear the increase and decrease at top and bottom). And the chart of big end loads at firing at high rpm does not clearly distinguish net up (long stroke) from down.
On repeatable measurements, micrometers are a challenge. It is difficult to repeatedly acheive the claimed accuracy. The anvils have to be free of oil film. The oil film in the thread changes with repeated closures. The static setting differs from measurement of an object. Errrors accumulate when using separate internal and external.