90 degree adapter and anti-drainback valve

KatanaPilot · #1 04-05-2018, 06:58 PM

I have a Titan IO-360-EXP in our RV-7A. It came with an installed 90 degree oil filter adapter and uses the Champion CH48108-1 filter. This filter has both a bypass and anti-drainback valve installed per Champion specs. The filter sits about 45 degrees upwards to the vertical when installed.

During cold starts (after the engine has sat for a few hours), the oil pressure is slow to rise. If the engine has run recently (like at a fuel stop), the oil pressure rises immediately.

I initially suspected a sensor issue, but the hot starts and immediate oil pressure put that to rest. Then I wondered if the orientation of the oil filter was allowing it to drain back in the engine - and it had to refill on subsequent starts before oil pressure could build.

I believe I confirmed that today when we changed the oil for the first time at 10 hours. We drained the sump hot but left the oil filter for later (like 5 hours later). Upon removal, I expected the usual pint or so of oil to drain out, but we got nothing. Not a drop. So while the anti-drainback valve might help with a filter in a horizontal or hanging down vertical position, it seems to do little to nothing in our installation.

The oil changes are very clean and access to the oil filter is very easy - but I am not happy about the essentially dry starts with this adapter. I don't really want to crank the engine with ignition off to build oil pressure, but that might be a possibility.

Am I missing something or is this just a "feature" of these adapters and does anyone have any suggestions (besides installing a pre-oiler)?

moosepileit · #2 04-05-2018, 07:10 PM

Try a Tempest or K&N?

KatanaPilot · #3 04-05-2018, 07:18 PM

Unless the Tempest or K&N anti-drainback valve works differently from the one installed on the Champion, I see no benefit.

Despite being a big fan of K&N and Amsoil synthetic media oil filters for automotive use, I prefer aviation grade components on my airplane. And yes, I've read the recent posts about the NAPA Gold filters. I even bought one of the cleanable Challenger filters today from ACS. Beautifully made, but no anti-drainback valve whatsoever - so it's being returned.

BillL · #4 04-05-2018, 07:59 PM

You might want to call Champion and discuss with them. The ADBV is silicone and should remain effective through its use service period. As a design feature, it would have to work in all orientations.

FWIW - - While it is a concern to ensure it is working properly, the edge of the cliff regarding bearing damage is not as close as you might think. One heavy duty engine diesel test is to run the engine for an hour at rated power until heat soaked, shut down, drain oil, remove the pan, remove the oil pump and drain the oil cooler. Then let it sit overnight to drip dry. In the morning start the engine, and run until until it labors and seizes. A bad result is when test lasts 30 min. A good test can last several hours. On the diesel engine under test, minimum rod bearing oil film thickness is at hi idle, not under full load.

Ironflight · #5 04-05-2018, 11:09 PM

I have that same angle adapter on two different engines, and the filters on both of them retain oil for a very long time - the anti-drainback valves appear to be working, at least with the Tempest filters (I haven;t used Champions for years). How many filter changes have you done and found the filter dry?

Paul

KatanaPilot · #6 04-06-2018, 03:44 AM

Thanks Bill. The anti-drainback valve (flapper) was intact. The issue seems to be that it only covers the intake (dirty) side of the filter. There is nothing preventing the oil from seeping through the filter and draining back on the outlet (clean) side. I would have called Champion yesterday, but it was after 5 PM. I will call them today.

Thanks Paul. This was the first oil change at 10 hours. The combination of an empty filter plus the repeatable indications of slow oil pressure rise on start had me conclude that the filter empties after sitting for a few hours. Do you get immediate oil pressure on all of your starts?

Walt · #7 04-06-2018, 07:07 AM

Every Mechanics dream, a filter that doesn't make a mess when you remove it

Ironflight · #8 04-06-2018, 08:53 AM

Quote:

Originally Posted by KatanaPilot

Thanks Paul. This was the first oil change at 10 hours. The combination of an empty filter plus the repeatable indications of slow oil pressure rise on start had me conclude that the filter empties after sitting for a few hours. Do you get immediate oil pressure on all of your starts?

I have never noticed a delay in oil pressure that bothered me. I doubt I get instantaneous 60 psi (I think I?d suspect the instrumentation if I did), but within a few seconds, yes.

KatanaPilot · #9 04-06-2018, 08:56 AM

Quote:

Originally Posted by Walt

Every Mechanics dream, a filter that doesn't make a mess when you remove it

My A&P son was there helping. We expected the usual mess, but there was none.

Further research with Champion and Continental/ECI indicates this is normal and the way these filters work with 90 degree adapters. There is no way to prevent drain back from the filter when it is upside down.

I don't like the 5-10 second delay for oil pressure, but I'm told not to worry about it and keep RPM's to a minimum until oil pressure rises.