318 compression calculator with KB167

It's confusing. We've covered this before and a lot of people don't understand it. Piston manufacturers SHOULD use the same method for measuring domes and dishes that calculators use. They don't.

When you enter info into a calculator or when calculating using formulas.....unless otherwise specified, you use a negative number for a dome (as the dome REMOVES chamber volume) and a positive number for a dish (as a dish ADDS TO the chamber volume). That's the way it's always been and always will be.

Some of these fancy online calculators have it reversed in their program and you enter the information actually backwards from correct, but since it's part of the program, it comes out right.

WHY they ever did that, I haven't a clue, because even though the answer comes out right, how they get there is DEAD WRONG and a cause for major confusion.

This is why on some calculators you see "this number should be REVERSED when figuring compression" or some such.