when you bore an engine it is said to be bored . 04 or .02 or what ever over, what unit of measurement is that? inches or mm? if you could provide a website, this would be great, i have been looking for hours.
2007-08-03 11:36:14 · 4 answers · asked by Ryan B 3 in Cars & Transportation ➔ Maintenance & Repairs
It's in thousandths of an inch. "40 over" would be .040"
2007-08-03 11:41:57 · answer #1 · answered by Jay 5 · 0⤊ 0⤋
Before a machinist bores an engine, he uses a tool called a dial bore gauge to check the wear in each cylinder, recording the readings as he goes. Once all cylinders have been measured, he looks for the largest measurement that was found and based on the avaliable replacement piston sizes, decides what the bore size will be. Pistons usually come in oversizes of .010, .020, .030, & .040. He has to know the size of the piston and the clearance that is specified for it. Then he sets up his boring machine and bores and hones all the cylinders to the same correct size.
2007-08-03 12:36:14 · answer #2 · answered by Ron B 6 · 0⤊ 0⤋
Normally it is said as, 10 or 20 over. The unit of measurement is a thousandth of a inch.
So it would be say 60 over, is saying that the cylinder walls have been bored .060" over the stock size.
This would apply to American engines.
If you are dealing with foreign engines with a metric bore, then I assume then it would be in millimeters or centimeters.
2007-08-03 12:02:34 · answer #3 · answered by Fordman 7 · 0⤊ 0⤋
An example, For 5.0/302 has a bore of 4.00. A 30 over bore would make it 4.03. Thats in inches.
2007-08-03 11:52:23 · answer #4 · answered by mad_mav70 6 · 0⤊ 1⤋