New engine II

Hi all!

Thanks to all that answered my last post! Very informative!

I have one more question regarding a factory overhauled engine.
Is it critical in any way to fly the first 25-50 hours quickly?
Can we shorten the life of the engine by letting the plane sit in the hangar
for many days/weeks between flights?
What's recommended? We are 5 co-owners, and quite often the plane will sit
in the hangar for a while between usage....especially during winter, but
that won't be an issue now obviously.

Anyone?

Frode Berg
LN-LMR

"Frode Berg" wrote

Can we shorten the life of the engine by letting the plane sit in the
hangar for many days/weeks between flights?

YES!!! That is the one factor that contributes most to shortened
engine life. Particularly during the initial break-in period if
one is using a "straight" mineral oil to facilitate the break-in.
The "straight" mineral oil, while promoting a faster break-in, also
drains off the camshaft lobes between flights more readily than does
a multi-viscosity oil with all of the additives. Several years back,
the situation was so bad with one particular engine, the Lyc O320 "H"
model, that the FAA required a special additive to be added to the
oil used in that engine to help the oil stick to the cam lobes between
flights. The additive was so sucessful that it is now a standard part
of the Aero Shell 15-50 oil sold here in the U.S.. At Sun-n-Fun a couple
of weeks ago, I saw vendors selling the additive alone. It wasn't
cheap, but compared to the price of an engine, it is well worth the
money.

The best advice....during the break-in period, use straight 50W mineral
oil and fly daily if possible and when the piston rings have seated and
oil consumption has stabilized, switch to a 15-50W detergent oil with
all of the additives.

Bob Moore
ATP CFI

"Frode Berg" wrote in message
...

I have one more question regarding a factory overhauled engine.
Is it critical in any way to fly the first 25-50 hours quickly?
Can we shorten the life of the engine by letting the plane sit in the
hangar
for many days/weeks between flights?

Mineral oil used for break-in has no additives to help
it stick to moving parts when the engine isn't running.
Also, before the cylinder rings seat, you'll get a lot more
blow-by into the oil which will make it dirtier quicker,
and subsequently acidic and corrosive. You want to minimize
the time you have that crud in your engine. So don't
let it sit for long periods & fly at least every day if you
can. At least for the first few hours.

FWIW, I flew the first 8 hours of my break-in in just
over a week & then drained and refilled with fresh
mineral oil. I didn't reach the 25 hour mark until about
3 months later. The first 8 hours were flown at close
to full throttle, and as far as possible below 4000' to
keep the MP up high. I replaced at 8 hours because
my after-market filter got clogged up with gunk so that
the bypass light came on & the oil was absolutely filthy.
Runs great now after 120 hours, oil consumption minimal.

Don't baby it. Fly it just under red line.


"Frode Berg" wrote in message
...
Hi all!

Thanks to all that answered my last post! Very informative!

I have one more question regarding a factory overhauled engine.
Is it critical in any way to fly the first 25-50 hours quickly?
Can we shorten the life of the engine by letting the plane sit in the
hangar
for many days/weeks between flights?
What's recommended? We are 5 co-owners, and quite often the plane will sit
in the hangar for a while between usage....especially during winter, but
that won't be an issue now obviously.

Anyone?

Frode Berg
LN-LMR