Re: oil pressure at the lifters at idle

Posted by HH56 On 2023/1/30 10:34:25

And the flickering also depends on the pressure rating and sensitivity of the switch installed. No idea what Packard specs were for the factory used switch but would be nice to know if anyone has documentation with that information.

The aftermarket replacements for inline 8s are hit or miss spec wise so I don't really trust what they say is factory correct. One parts store offers a switch that has a nominal rating of 6 psi but looking at the switch spec it has a fairly wide range of 3-8.3 psi where it will operate. Another replacement switch that a different store had as correct a few years ago gave a nominal rating of 12 psi but with a range of approximately 10-15 psi.

The switch that will close if it falls below the lower pressure will not flicker as much as one that closes below the higher pressure. Tradeoff comes with what safety margin you are comfortable with. The options are one that might flicker a lot but gives a solid warning if pressure drops below approx 10 psi or one that does not flicker at all but also might not signal a problem until the pressure drops below 3 psi which IMO, is quite low. Downside to one that flickers a lot is you get used to it and might tend to ignore a real issue and one that will only signal at a very low pressure might have already had damage done.