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Someone asked what's involved in
plumbing a pre-oiler.
As one of the Infinity oil pump
pioneers (the guy with the arrows in his back),
I thought I'd share what
I've encountered while installing an Infinity GP302-12 preoiler pump
on my Lancair ES with Continental
IO-550N engine.
Skip Slater is right -
the Infinity is "just a pump" - it's up to you to get
the rest of the parts.
On the other hand - the
Oilamatic current list price is $1,195 for 12volt, $1,245
for 24 volt.
For the Cont IO-550, you'll also need
the $195 oil filter adapter. So the "list price" is about
$1,400.
I had to find the following parts to
complete the Infinity installation:
Oil sump
pickup. At first I considered tapping into the oil pan drain
plug, but it's hard to find the correct style
fitting.
As it turns out - you can get them
from West Marine ($20, but special order for the 5/8" x 18tpi).
These are standard parts
for their electric oil change pump out kits, but that size is a special
order.
Same concept - but that got me
thinking I didn't want to preoil with sludgy oil off the bottom of the
pan,
also it doesn't have a screen on it
to prevent picking up chunks / debris.
So the ideal pickup is an oil suction
tube - just like the engine drive pump uses.
It turns out you can use the existing
Continental suction tube since it is plugged at the Accy case.
with a standard 5/8" x 18tpi plug and
a copper crush gasket.
I found a fitting that was "close",
and then had the threads modified on one end to 5/8" x 18tpi.
(Cost of the fitting $5, cost
of the modification $10).
So now I have the same pickup point
for both the engine driven pump AND the electric preoiler.
The oil suction tube has a screen, it
sits slightly up off the bottom of the pan, and it's convenient.
Where the plug was, now there is a
hose connection to a -10 hose.
The trick is now where to
insert the pressurized oil from the electric oil pump back into
the engine.
Ideally - it would be after the
engine driven oil pump, and before the oil filter, cooler, vernatherm,
etc..
Unfortunately - there doesn't appear
to be any suitably large port that fits this bill.
I called TCM and they weren't much
help.
That's where the $195
Filter Adapter at www.Oilamatic.com comes in
handy. Or, if you have a remote oil filter, you can
simply T it into the line going to
the oil filter. As Skip noted, you need to have a check valve as
well.
The Infinity guys suggested
www.Stratflo.com and I bought
their brass & stainless #400 in a 1/2" Pipe for about $32
?
If you didn't want to use the filter
adapter, you could use an automotive, marine, or aviation oil
filter
dedicated to the electric pre-oiler
pump. The output from this can then be inserted into any oil pressure port
on the gallery.
I considered doing it this way - but
prefer the oil filter adapter and using the regular engine oil
filter.
The advantage of the
solid metal "oil filter adapter" is that there are no
additional hoses on the "engine side" of the
checkvalve.
But if you already had a remote oil
filter - by all means, just T the check valve into that line.
The other thing I had to
track down was an oil pressure switch. I special ordered one at
Gotelli's
Speed Shop.
I think it was made by the same folks
that make the Hobbs meters and switches. There are a couple of models that
would do,
but I settled on one that was
Normally Closed (unusual - most are normal open), with a pressure point around
55psi or 60psi.
This switch cost
about $50. I splurged and got the rubber electrical cover that
goes over it for $7.
You'll still need a switch & 15A
circuit breaker inside the cockpit - otherwise the pre-oiler will run whenever
the master is on.
Cost of these electrical parts is
about $20.
Plumbing the switch in - I
substituted a brass 4-way "cross fitting" with 1/8" FPT. Now my pressure
transmitter,
pressure switch, and a spare port for
a mechanical calibration gage - are all connected by the standard -4
hose
over to the engine. That entire
line is protected by a restrictor orifice in case the hose or a fitting were to
leak.
Total "additional cost" of the
plumbing (swapping the tee to a cross) was about
$3.
Infinity sells two models in two
voltages. The "GP301-xx is limited to intermittent pre-oiling duties,
the larger GP302-xx is rated for
continuous operation. Both are available in 12 and 24 volt.
GP301-12 was $360.
Continental recommends limiting your
pre-oiling pressures to 60 psi...
So with the above switch - if the
pressure hits 60psi, the electric pump will stop automatically.
(I think the 60 psi limit mostly
applies when the engine isn't running - to prevent blowing out
seals.)
Then the next bit of fun is finding
the fittings to go into the Infinity pump.
Pumps for some arcane reason come
with straight (not tapered) pipe threads. The Infinity pump includes
a little Male to Female adapter on
each side of the pump. This helps provide clearance around the pump
head,
and converts to tapered pipe thread,
and provides a replaceable set of threads to protect the pump
threads.
You'll need two "hose-to-pipe"
fittings for the pump. 3/8" MPT on one side, and 37 degree JIC fitting on
the other.
Straight or angled - depends on where
you put the pump.
The last piece of the plumbing puzzle
is two hoses. The bigger the better - so I went with -10
hoses.
Done right - they will be Teflon,
fire sleeved, 37 degree fittings, and have angled connections as
necessary.
I haven't bought my hoses yet, but I
expect to spend about $200 for hoses. I don't know if
those are included
in the Oilamatic system or
not.
Since this installation is still in
progress - now I'm considering adding a check valve on the suction side of the
electric oil pump as well. The
fitting I made that goes into the top end of the oil suction pickup tube, is
safety wired
and accommodates a copper crush
gasket - just the same as the drain plug that it replaces.
My concern was that an air leak on
the suction side - might cavitate a perfectly fine engine driven oil
pump.
So I'm thinking about changing the
suction pickup line to include another Strataflo check valve -
so that even if the suction hose on
the engine driven pre-oiler were to fail, that it wouldn't affect the "normal"
oil supply.
I know I spent days tracking down all
the various parts needed to do this. I don't know how much time I would
have
saved if I had gone with the
Oilamatic. But, if you can use any of this info - the Infinity oil
pump is a nice beefy unit
that should certainly be up to the
task. All told - I'll probably have $800 in materials, and days worth of
time finding parts.
I'm sure the money saved doesn't
outweigh my time spent tracking down the parts. But I am satisfied with
the
final design of the system.
When I tried plumbing the system as Infinity suggested (with an adapter in the
oil pan drain),
I too had visions of using the pump
to facilitate oil changes. (That's what the boaters do.) Sadly, I
won't be able to
pump out all the oil with this - so
I'll still have to add a pricey oil "quick drain" and just wait for the oil to
drain out.
I was very concerned about the
Continental IO-550 "vertical" (and upside down!) oil filter. I thought
that would be
a real mess to change. But it
drains quite nicely - with only a little residual oil in the filter. Also,
the TCM rep
at Oshkosh told me a little trick -
to just tap a hole at the top of the oil filter - and that releases the
pressure
and it will drain almost
completely. So for now - I'm not planning on a remote oil filter.
(Two less hoses!)
Hope it helps,
Greg
GP302-12_PreOiler.jpg
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