Pistons specs question for 340 build

70Hardtop said
But it does make sense that if you remove material from a piston it would be stated as a negative value. I think the calculators for CR need the +ve values as it's CR that is going to be the end result and increasing volume decreases the CR.

But anyway, not wanting to sound like a broken record (and yes I grew up as a school kid buying Alice Cooper and Led Zep records for $4 each...), I'm hoping that someone reading this thread knows if the DSS Racing pistons are lighter than the popular KB Hyper's. I have read that the DSS are rated as on the heavy side for a forged. And I know the KB's, even though technically a cast piston , are lighter than the stock ones. But I need some numbers hopefully and I don' know why manufacturers don't post the weight of their pistons in their specs - well maybe the top dollar ones do but I haven't seen any weights for shelf pistons.

Where the confusion comes in is that ultimately we're not talking about the piston at all. We're talking about volume. So in that sense, taking away from the piston adds to volume and must be looked at with a positive number when making calculations. Conversely, when a piston takes away volume, such as a dome, you must use a negative number when making calculations. That's not debatable. That's math and math doesn't lie.

Now, if you're using calculators that calculate that backwards, like evidently the Wallace calculator does, then you have to use the numbers like you're saying. But with a standard formula for volume you'd be backwards.