Mash Tun Dead space

[Chris Craig]

What do you all use for a dead space calculation in your mash tun?  I used to use 2L before I got my new bulkhead for my 48qt Coleman cooler.  I've had to increase that to 8L because I found that I was always short on my sparge water.  For the longest time I thought that was just an inaccuracy in the calibration of the sight glass for my HLT because I got that around the same time.  But, I just re-calibrated that tonight, and it was bang on.

Does 8L seem like a high value to you guys?