Nasa Icing courses

On 1/18/2006 11:44 AM, wrote the following:
On Mon, 09 Jan 2006 16:10:22 GMT, George Patterson
snip

I can't think of a single engine in the automotive world that depends
on splash oil to lubricate anything.


Hmm ... In every engine I've ever assembled the cam lobes running against the
tappets are splash oiled. In pushrod motors the rocker arm noses running
against the valve stems are splash oiled. Also the timing chain(s), the
distributor drive gear, ... Pretty much it is only the bearings that are
pressure oiled. i.e., mains, rods, cam(s).

YMMV, of course.

On Wed, 18 Jan 2006 13:40:21 -0600, Mitty wrote:

In pushrod motors the rocker arm noses running
against the valve stems are splash oiled. Also the timing chain(s), the
distributor drive gear, ... Pretty much it is only the bearings that are
pressure oiled. i.e., mains, rods, cam(s).

The engines pushrod engines I've assembled had hollow pushrods and fed
pressurized oil to the rocker arms. The rocker arms were hollow and
injected oil onto the valve stem to assist in cooling. Yes, the top
of the valve stem did not have any direct injection so it did require
splash oil for it's lubrication. That's where roller rockers help.

Guess I hadn't thought that much about it for a long while. I stopped
working as an auto mechanic a long time ago.

Corky Scott

How, in a horizontally opposed engine with an external oil sump (like on
the C85 or 0200 or lots of others) do the crankshaft lobes "splash" oil
anywhere meaningful? The cam has to be lubed by some other mechanism.


-----Original Message-----
From:
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Posted At: Wednesday, January 18, 2006 3:05 PM
Posted To: rec.aviation.ifr
Conversation: Nasa Icing courses
Subject: Engine Making Metal (Was: Nasa Icing courses)

On Wed, 18 Jan 2006 13:40:21 -0600, Mitty wrote:

In pushrod motors the rocker arm noses running
against the valve stems are splash oiled. Also the timing chain(s),
the
distributor drive gear, ... Pretty much it is only the bearings that
are
pressure oiled. i.e., mains, rods, cam(s).

The engines pushrod engines I've assembled had hollow pushrods and fed
pressurized oil to the rocker arms. The rocker arms were hollow and
injected oil onto the valve stem to assist in cooling. Yes, the top
of the valve stem did not have any direct injection so it did require
splash oil for it's lubrication. That's where roller rockers help.

Guess I hadn't thought that much about it for a long while. I stopped
working as an auto mechanic a long time ago.

Corky Scott

Jim Carter wrote:
How, in a horizontally opposed engine with an external oil sump (like on
the C85 or 0200 or lots of others) do the crankshaft lobes "splash" oil
anywhere meaningful?

Disclaimer: I have no specific knowledge of the engine models mentioned.

The oil that's pushed under pressure through the crankshaft rod and main
bearings has to go somewhere. I picture it as a sort of whirling fog of oil
droplets inside the crankcase.

Specifically, *don't* picture the various crankshaft protrusions actually
contacting the surface of a pool of oil, that's not what happens.

The cam has to be lubed by some other mechanism.

The cam bearings have their own oil passages and are lubricated under pressure
from the oil pump. The cam lobes have no such lubrication.