bore question?
71 cuda'
05-30-2006, 02:42 PM
hi, when you bore your engine .20 over does that mean 2mm? and like .30 over is that 3mm more?
MagicRat
06-01-2006, 07:32 PM
No. you are confusing metric and English measurements.
.020 means the bore (diameter) increases by 2/100ths of an inch. This means that only 1/100ths of an inch of metal is removed from the cylinder wall itself.
Overbores are measured in metric as well. a 0.75mm overbore is approximately equal to a .040 inch overbore.
.020 means the bore (diameter) increases by 2/100ths of an inch. This means that only 1/100ths of an inch of metal is removed from the cylinder wall itself.
Overbores are measured in metric as well. a 0.75mm overbore is approximately equal to a .040 inch overbore.
MrPbody
06-02-2006, 07:49 AM
Close... One millimeter is .0394". A piston marked ".5" means about .020" over. .75, .030", and so on.
Older (American) cars are entirely "inch" system. In the late '70s, there was a trend to "metricize" American products. While it worked with manufacturers, it has not yet taken "hold" in the aftermarket. A shop like ours uses "standard" measuring devices and "converts" metric. A couple more generations, and we (USA) will be completely "metric". Dinosaurs like myself will be either dead and gone, or "retired'... (:-
If you want to talk "muscle cars", you must be fully versed in "inches". The only true muscle car to use the metric system entirely, is the current version of GTO.
Jim
Older (American) cars are entirely "inch" system. In the late '70s, there was a trend to "metricize" American products. While it worked with manufacturers, it has not yet taken "hold" in the aftermarket. A shop like ours uses "standard" measuring devices and "converts" metric. A couple more generations, and we (USA) will be completely "metric". Dinosaurs like myself will be either dead and gone, or "retired'... (:-
If you want to talk "muscle cars", you must be fully versed in "inches". The only true muscle car to use the metric system entirely, is the current version of GTO.
Jim
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