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Old December 31st 07, 11:10 PM posted to rec.aviation.homebuilt
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Default engine pre-oiler

On Dec 31, 11:28 am, cavelamb himself wrote:
Maxwell wrote:
"cavelamb himself" wrote in message
...


KISS!


Keep it Simple stupid.


AND


Lighter is better.


Agreed. But what do you suggest would be lighter and simpler?


Well, the first question is - does it really NEED a pre-oiler?

If it has roller tappets installed, it really doesn't need the preoiler.

If it doesn't have roller tappets, I'd add those before adding an oiler.

YMMV

Richard


The case has to be remachined to accept roller tappets; the
bore is squared off to keep the tappet roller lined up with the cam.
And the cam profile is different.
In short, you buy an engine from Lycoming.

The preoiler still helps with bearing wear. My A-65 had the
front rod bearing and crank journal badly worn, since the oil arrives
some time after start. The wear was a little less on the next journal,
and the back two improved over that. Told me that the front bearing
was oil-starved for too long too many times.
The galleries drain after shutdown, though the bearings and
tappet bores. Preoiling helps, at least in this old engine. The
Lycomings we fly every day in training don't have any wear issues and
could easily go 3000 hours. They're still really strong at TBO.

Dan