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Gary/Colyn -
The 320 I built has the 'short' engine
mount, which doesn't provide nearly enough clearance for an
aviation filter. I wasn't about to punch a hole in the firewall or resort
to a right angle adapter, so I checked automotive filters and identified the
Mobil M1-107 as small enough to install in
the available space and having a gasket which matches the Lycoming
spin-on's sealing surface. I didn't check the 107's flow rating, but
it's applications include GM V-8 engines up to 364 cid, so I felt
comfortable that it could handle the flow rate in my 4 cylinder, 320 cid
Lycoming. I'm not knowledgeable of aviation versus automotive oil filter
pressure ratings, but Mobil claims that the M1 "withstands up to nine
times the normal system operating pressure" and that seems pretty high to me
(I've also never heard, or read, of even the cheapest automotive filter
rupturing). On top of all that, it's functioned flawlessly in my 320 for
over ten years and I believe Mobil's claim that it "removes more contaminants
than conventional filters using an advanced synthetic fiber blend filter
media". I think it's great that we experimentals can take advantage of
some modern, advanced automotive technology.
As for lockwiring, I drilled a 1/32" hole through
the hex head of a Breeze clamp, then snugly tighten the clamp around the base of
the filter and lockwire the hex head to a 1/32" hole drilled in a
small fin at the rear of the oil temperature probe housing.
Bill Rumburg
N403WR (Sonic bOOm)
----- Original Message -----
Sent: Monday, May 05, 2014 7:16 AM
Subject: [LML] Re: Oil filter
I was told once (a long time ago) that the
main difference between automotive and aircraft filters is that the aircraft
filters are built for a much higher maximum pressure. Feel the weight -
you can tell the metal is thicker. At some pressure any oil filter will
distort enough to lift the seal off the surface and blow oil out. The
problem occurs on a cold-oil takeoff - max rpm with cold oil. I doubt
very much if an automotive oil filter will exceed its pressure rating (which
is something around 500 psi), but that's what I was told once upon a time.
Another difference is that certified aircraft oil filters have to have a
means for positively retaining the filter - a safety wire tab. However,
I have never seen or heard of an oil filter coming loose after having been
tightened reasonably. The final difference is that aircraft filters have
to have a means of measuring installation torque. But other than that, I
suspect automotive filters are at least as good as the aircraft version.
You pays your money and takes your choice, I guess.
Gary Casey
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