BillL
Well Known Member
Oil cooler, then to the filter.
My notes say 12~14, but I don't recall a Lycoming source for the information. Multiple non-OEM sources (Aviation Consumer, Tempest, etc) say the Lycoming adapter is in that ballpark. I think Donaldson makes the adapter for Lycoming, but I can't find specs at their site. Given all the STC'd non-bypass adapters out there for Lycoming, all of which would use 108/109 filter, I think we're pretty safe assuming the filter bypass delta is the same for all.
I did find this Tempest note on my hard drive. Worth a read. Here's a web link:
https://tempestplus.com/wp-content/uploads/2019/01/Alaska-Cold-Starts-0613.pdf
Thanks, Dan, I did not see that in the Tempest docs.
That opening pressure is what I figured it might be, maybe less since Tempest claims their filters meet the Continental spec implying it is higher. Regardless, the attached doc is also good for the library. It is a good glimpse into the reason for tough test and design standards in ARP1400.
https://www.championaerospace.com/w...l-Filters-vs-Tempest-Competitive-Analysis.pdf
This Champion doc shows the pressure drop vs capacity. Hot oil test, so cold starts and log oil change intervals apply. Also, we should note that the efficiency testing allows caking on the element to improve efficiency. Obviously at the cost of pressure drop. No free lunch, and enlightenment for users that a new filter is not as good as an old one in it's filtration effectiveness.
Also, the temporal changes of the oil system yield a filter that is better at the end of life, but the oil increases in contaminants from clean (0 hr) to a plateau somewhere down the road. Diesels reach that plateau in 50 hrs, but they have larger sump capacity. No clue what the Lycs or if it has ever been documented.