Best Oil cooler capacity check and proper Fill method

[MrFairlady]

Whats the best way to measure the correct Oil amount when installing an oil cooler.

My car has a Moroso Oil pan (5qt pan) Tomei Oil block, the Greddy Relocation/Thermostat (using 2 - 2'+/- sections from the Block to the Filter) and a Earls 15 Row cooler (using 2 - 3' sections to the fornt of the car). -10 lines of course.
nothing Extreme though I may get a bigger cooler.

Anyway.....hows the best way to measure how much total oil it should hold in the cooler,lines and everything and the pan so there's no question of too much or not enough oil.
***Aside from Filling the cooler alone and measuring how much it holds,and just guessing on the lines.
Any other way?
Part 2 of this is,.. while it has a Thermostat built in..Wouldn't that mean that unless it gets hot enough to open fast/soon,the Pan is going to be holding a TON of oil (more than the 5 qts i would think) untill it Pushes through to the cooler for normal Circulation?? :confused:

[fliprayzin240sx]

You're over analyzing it. Just check the dipstick when you fill it. Let the car run and wait to ensure the thermo opens up so itll let oil into the cooler, then check the oil again. Remember, when you turn off the car, you'll still have oil in the cooler, you almost never get that oil out when you change your oil (unless you want to take your cooler out and pour the oil out of it).

Everytime I changed my oil, my oil level always changed. There were days I've poured 6 qts in mine, there were days I only had to pour 4.5 qts. I had a Greddy pan and HKS thermo/cooler setup.

[articdragon192]

Some thermostats also don't close all the way, allowing for a small amount of oil to flow through still.