Michael,
I'll join you on the fence. My engine builder doesn't use them. I may do some bench testing to see if the valve is working properly. I re-read the instructions for it. They state to add 1 qt of
oil or add
oil to the FULL mark on the dipstick. Suppose you chose the later, and you're using a 2qt model, and precharge it to 7psi as instructed.
You can calculate the volume of
oil stored in the tank (assuming a constant temp ideal gas) by using Boyle's Law, which is:
Pressure * Volume = constant
The 2qt tank is 4.0 ID x 12 in long, thus has a volume of 150 in3 at 7 psi. If we compress the air to 60 psi isothermally, the new volume is 17.5 in3. Thus the tank will hold 150 - 17.5 = 132 in3 of oil or 2.29 qts. Yikes, this means that your 7 qt pan now has less than 5 qts in it. Would you drive your baby around down 2+ qts?
Chuck (sorry for the engineer math)