Is there  any reason I can't put the oil filter between the oil pump and
oil  cooler?
That way I can mount the filter on the firewall and use a  large one along
with an oil accumulator since my oil pan is so  small. Heat might be an
issue.

Doug in  Japan

No I think that will work. The pressure the oil cooler  sees will
be reduced somewhat. I have no record of anybody doing  that before.

BTW every time you pump oil through a right angle  at high flow rate
you add heat to the oil and reduce the pressure.  You can eliminated
two of them by taking oil directly out of the  front end housing.
This is a Lyn Hanover modification. Rumor has it  it will reduce
the oil temp by 10 or 20 F. Use a straight thread tap  and O ring
fitting. A pipe tap could crack the front  housing.

Paul Lamar

Hi Doug;
Filtering  before the oil cooler is preferable if the cooler can handle
the  pressure - you probably want at least 150 psi rated for cold
northern starts.
Look at 3rd gen or Rx8 coolers.
For oil  filters, Lynn explicitly recommended against certain brands such
as  fram (that is another topic)
I believe he also recommended synthetic  straight weight 40 weight oil in
the sump + 2stroke pre-mix in the  fuel, unless you fly in the frigid
northern climates in winter like  here.
Cheers
Cary

snips....

I don't see anything in my notes about recommended filters. I would
appreciate a suggestion.

Doug in Japan

snips............

I  forgot to mention that new oil inlets such as #2 (in particular) in
the  engine pictures above have very little meat on Rx7 13B's. Plenty on
12A's.  Haven't done the mod on RX8s. RX7 13B's required a bottoming
tap to get  enough usable  threads.

Cheers
Cary

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I would stick with Setrabe oil coolers as we have had oil  coolers
from other suppliers split and in one or two cases cause an  inflight
fire. I know these Setrabs work. Don't cut corners on this by  using
coolers designed for other purposes. The engineers know what  they
are doing. One of the big issues is the heat transfer rate from
the  oil to the metal. Low viscosity oils cool better.

Paul Lamar


Wix used to be a division of Dana Corp in Toledo Ohio. And may  still be.
Makers of thousands of products for the automotive and truck industry.
Wix
and Champion make most of the aftermarket oil filters. That is, store or
house brands like STP and the like. They are also sold as WIX filters by
NAPA.
Champion also makes filters for airplane engines. All oil filter companies
fill  their catalogs with each others filters. Those big filter catalogs
do
not mean  that every company makes thousands of different filters for
every
known  application. All the way up to truck air elements that your kids
could hide in.  Of course they test each others filters as well. Everyone
has
water separators  for diesel powered trucks, but generally Facet make
almost
all of those, even  though every catalogue has those filters under dozens
of
part numbers. The  Wix promotional kit used to be a cut open Fram PH8A and
a
cut open Wix 51515  both the fit everything Ford for years and years and
most filter stands. The  Fram had 104 square inches of paper and the Wix
had
316 square inches of paper.  I blew a Fram off of the filter stand on my
racer one day and damn near lost my  racer and the shop.

The crimp at the top of the can unrolled. That was about 100 PSI on  a
warm
summer day. The Wix can is rated at 350 PSI. The K&N is 550 PSI. One
element should be enough, but call up the tech guys at K&N to be sure on
the
flow rate. Do not say "airplane" during your conversation.

The Setrabs have never failed me. I once place a potato chip  looking
Setrab between two pieces of plywood and ran over it with my van to
straighten
it out. It finished out the season with no leaks.

One advantage of the oil out location in line with the pump, in the  front
iron, is that you can plug the gallery in front of the "O" ring  junction
that Mazda should have eliminated years ago. All of the fixes involve a
thicker gasket or "O" ring protector to add pressure to the junction. The
front
cover has no bolt or stud close to the junction and the cover is flexible
and  under startup cold oil pressure the cover is pushed forward and
allows
the "O"  ring to escape. The deformed section of the "O" ring then is
trapped
between the  iron and front cover, holding the junction open, and most oil
pressure is lost.  About 30 PSI is all that you will see if this happens.

Starting up with no prop (or load to limit RPM) or in very cold  weather
with straight weight oil. There was a relief plunger in the circuit just
ahead of this junction that should prevent this problem but it is set at
140 PSI
   and that is a bit higher than useful.

The "Banjo" fitting into the rear iron is a flow disaster and FEMA  should
send out AN fittings to replace it.

Lynn E. Hanover

--

Lynn,

Thanks.  It is always good to hear from you, even when I don't like what
I hear:)
Seriously I know the Setrab are bullet proof but they quite large in area
and I'll need to get creative on mounting it so that I can get to the
spark plugs.  The Fluidyne one pass model would be perfect but as yet I
don't have enough info on the unit.   Thanks for the info on K&N
filters.

Doug in Japan.


A mechanic friend recommended I place my oil filter downstream of the
cooler for the following reason:  Combustion byproducts in the oil
saturate out in the cooler and plate out on the internal surfaces.
Eventually, some of them flake off and would damage engine bearing
surfaces if not stopped by the filter.

A thorough cleaning of the cooler should be part of a major overhaul, but
is too often overlooked.

Philip Groelz