Small Continental Oil Press???

[Paul Anton]

What can anyone tell me about "loss of oil pump prime" on a small
Continental?

I have heard of it in the past and it has happened to me.

The engine in question is a C-85 that has been very recently overhauled to
new limits. The case and accessory case was overhauled by ECI. New oil pump
gears, oil pressure relief plunger, etc etc.

It has an oil filter adapter that mounts where the oil cooler would mount.

I drained the oil and filled the sump immediately, the filter came off a day
or so later and a new filter was put on. Now the engine sat for ten days to
two weeks before starting. No oil pressure on start up. Gage is just fine,
it really is a case of no oil pressure.

At the same time I was doing the same thing to an 0-200 configured the same
way with the STC oil filter. About the same time lapsed between replacing
the filter and starting the engine. Oil pressure came up on 15 seconds.

An annual was being done on two planes at the same time. This accounts for
the delay on the oil filter change and the start up.

Why did the pump loose its prime? How best to get the prime back? What can I
do to prevent this in the future.

I suspect the oil filter mount has a great deal to do with this problem.

Any enlightening comments would be appreciated.

Thanks

Paul Anton

[Cy Galley]

The filter plate is so far from the oil pump that it is not a factor. Some
times one can "prime" the pump by tipping the plane on its nose for about 30
seconds. Don't let the cowl touch the ground. The other way is to remove
the gage fitting and pump oil into the hole. Reattach and start.

Did you use a new pump cover or just the old one? I would talk to ECI if
they did all you said they did.


--
Cy Galley - Chair, Emergency Aircraft Repair
Safety Programs Editor - TC
EAA Sport Pilot
"Paul Anton" > wrote in message
...
> What can anyone tell me about "loss of oil pump prime" on a small
> Continental?
>
> I have heard of it in the past and it has happened to me.
>
> The engine in question is a C-85 that has been very recently overhauled to
> new limits. The case and accessory case was overhauled by ECI. New oil
pump
> gears, oil pressure relief plunger, etc etc.
>
> It has an oil filter adapter that mounts where the oil cooler would mount.
>
> I drained the oil and filled the sump immediately, the filter came off a
day
> or so later and a new filter was put on. Now the engine sat for ten days
to
> two weeks before starting. No oil pressure on start up. Gage is just fine,
> it really is a case of no oil pressure.
>
> At the same time I was doing the same thing to an 0-200 configured the
same
> way with the STC oil filter. About the same time lapsed between replacing
> the filter and starting the engine. Oil pressure came up on 15 seconds.
>
> An annual was being done on two planes at the same time. This accounts for
> the delay on the oil filter change and the start up.
>
> Why did the pump loose its prime? How best to get the prime back? What can
I
> do to prevent this in the future.
>
> I suspect the oil filter mount has a great deal to do with this problem.
>
> Any enlightening comments would be appreciated.
>
> Thanks
>
> Paul Anton
>
>
>

[jls]

"Paul Anton" > wrote in message
...
> What can anyone tell me about "loss of oil pump prime" on a small
> Continental?
>
> I have heard of it in the past and it has happened to me.

Only way it can happen imho is if there's slop in the oil pump, i. e., the
cover and/or pump wells are wallowed out or too much wear in the gears and
bushings. I bet if you pulled the rear case you'd find something out of
tolerance. Check your gear lash too, with feeler gauges and a dial
indicator.

I had an A-65 that would do that. The rear case is magnesium, same material
as the C-85's. Every time I cranked it-- even the next day -- I would have
to raise the tail to prime it. When I tore that engine down the shafts,
gears, cover, and bushings were all out and so were the wells. When I
overhauled it I had to replace the rear case and the gears and cover, an
expensive proposition. Before it went back together I miked everything to
make sure of tolerances required in the overhaul manual. Those tolerances
are unforgiving.

I just tore into a C-85 needing overhauling. One of the oil pump shafts is
scored all to hell. We'll see how much more slop there is in it. The
cylinders of this engine, used on an experimental, are fried, probably
because of the crappy baffling and baffle seals.

Best wishes. I have almost 200 hours on the A-65 now and she is a real
trooper, although the ECI cermichrome cylinders are predicted to die early.
Only trouble so far --- a blown exhaust gasket which made everybody on the
field think the engine was sick.
>

[Bob Olds]

" jls" > wrote in message >...
> "Paul Anton" > wrote in message
> ...
> > What can anyone tell me about "loss of oil pump prime" on a small
> > Continental?
> >
> > I have heard of it in the past and it has happened to me.
>
> Only way it can happen imho is if there's slop in the oil pump, i. e., the
> cover and/or pump wells are wallowed out or too much wear in the gears and
> bushings. I bet if you pulled the rear case you'd find something out of
> tolerance. Check your gear lash too, with feeler gauges and a dial
> indicator.
>
> I had an A-65 that would do that. The rear case is magnesium, same material
> as the C-85's. Every time I cranked it-- even the next day -- I would have
> to raise the tail to prime it. When I tore that engine down the shafts,
> gears, cover, and bushings were all out and so were the wells. When I
> overhauled it I had to replace the rear case and the gears and cover, an
> expensive proposition. Before it went back together I miked everything to
> make sure of tolerances required in the overhaul manual. Those tolerances
> are unforgiving.
>
> I just tore into a C-85 needing overhauling. One of the oil pump shafts is
> scored all to hell. We'll see how much more slop there is in it. The
> cylinders of this engine, used on an experimental, are fried, probably
> because of the crappy baffling and baffle seals.
>
> Best wishes. I have almost 200 hours on the A-65 now and she is a real
> trooper, although the ECI cermichrome cylinders are predicted to die early.
> Only trouble so far --- a blown exhaust gasket which made everybody on the
> field think the engine was sick.
> >



************************************************** ******************************

I used to have the same problem with my Taylorcraft/Cont. A-75. If I
drained the oil and cleaned the screen and didn't run it as soon as I
put the oil back in it wouldn't prime the pump if it sat for a day or
two. I would have to pump oil into the oil temp fitting or somewhere
on the accessory case where I could get oil into the oil passages.
This happened a couple of times before I figured out the cause. NO
more problem if I refilled and ran it afterward.

Bob Olds A&P
Charleston,Arkansas


************************************************** ******************************

[Dan Thomas]

(Bob Olds) wrote in message >...
> " jls" > wrote in message >...
> > "Paul Anton" > wrote in message
> > ...
> > > What can anyone tell me about "loss of oil pump prime" on a small
> > > Continental?
> > >
> > > I have heard of it in the past and it has happened to me.

The oil pump gear cover plate inside the case is leaking oil.
It's a metal-to-metal fit to the case, and if the rebuilder doesn't
use a bit of sealant on it the oil will gradually drain out of the
pump gears, leaving them dry and unable to generate enough suction to
raise the oil from the tank. Pumping a bit of oil through the temp
probe hole or whatever wets the gears again and it'll go to work.
Tipping the airplane forward might help, if it's a taildragger, as the
residual oil in the screen would run forward and drop into the pump.

Dan