New Lycoming cylinder

[Robert M. Gary]

I just replaced a cylnider in my IO-360 with a new cylinder kit from
Lycoming. Where can I find the service instructions on how to
correctly break the cylinder in?

[Jim Burns[_2_]]

http://www.lycoming.textron.com/cgi-bin/search.pl?query=break+in+procedure

A new nitride cylinder will break in fast. Keep your power high, don't baby
it. Straight mineral oil.

Jim

"Robert M. Gary" > wrote in message
oups.com...
> I just replaced a cylnider in my IO-360 with a new cylinder kit from
> Lycoming. Where can I find the service instructions on how to
> correctly break the cylinder in?
>

[Robert M. Gary]

On Aug 31, 11:02 am, "Jim Burns" > wrote:
> http://www.lycoming.textron.com/cgi-bin/search.pl?query=break+in+proc...
>
> A new nitride cylinder will break in fast. Keep your power high, don't baby
> it. Straight mineral oil.

Now the A&P is saying that mineral oil is out-dated and that modern
synth oils are better for break in than mineral oil.

[Jim Burns[_2_]]

Interesting.
I'd call Lycoming on that before I'd let anybody try synthetic oil in my new
cylinder. It's my understanding that the reason straight mineral oil is
used for break in is that it does not contain detergents, adjuvant, or
anti-wear agents. Mineral oil will allow the proper amount of heat,
friction, and pressure to develop in the cylinder necessary to allow your
rings to set properly, without suspending particles and forcing them back
through your new cylinder. Unless somebody has developed a special
synthetic oil designed for break-ins, I would think that a synthetic oil
would contain these undesirable agents. I would also suspect a synthetic as
well as being "too slippery" or capable of removing too much heat,
preventing the rings from setting properly.

What brand/type of oil is your A&P recommending? Any supporting info from
the manufacturer? Lycoming?

Jim


"Robert M. Gary" > wrote in message
oups.com...
> On Aug 31, 11:02 am, "Jim Burns" > wrote:
> > http://www.lycoming.textron.com/cgi-bin/search.pl?query=break+in+proc...
> >
> > A new nitride cylinder will break in fast. Keep your power high, don't
baby
> > it. Straight mineral oil.
>
> Now the A&P is saying that mineral oil is out-dated and that modern
> synth oils are better for break in than mineral oil.
>

[Dan Luke[_2_]]

"Jim Burns" wrote:

> A new nitride cylinder will break in fast. Keep your power high, don't baby
> it.

Right.

And keep it cool so it won't glaze. Full rich or close to it, cowl flaps wide
open.

--
Dan
T-182T at BFM

[Robert M. Gary]

On Aug 31, 2:49 pm, "Dan Luke" > wrote:
> "Jim Burns" wrote:
> > A new nitride cylinder will break in fast. Keep your power high, don't baby
> > it.
>
> Right.
>
> And keep it cool so it won't glaze. Full rich or close to it, cowl flaps wide
> open.

Actually my concern is not getting it hot. My engine CHT's run about
290-300F in the winter and 360-380 in the summer in cruise. I'm afraid
that won't be enough to get a good seating.

[Jim Burns[_2_]]

If I remember, you're non-turbo'd, right? Fly below 6000ft density alt and
you should be able to develop 65-75% power at full throttle, high RPMs, and
a nearly full rich mixture. This should seat the rings just fine. It's the
pressure in the cylinder forcing the rings outward that seats them. Keep
the head cool so your new valve seats don't wander.
Jim

"Robert M. Gary" > wrote in message
oups.com...
> On Aug 31, 2:49 pm, "Dan Luke" > wrote:
> > "Jim Burns" wrote:
> > > A new nitride cylinder will break in fast. Keep your power high, don't
baby
> > > it.
> >
> > Right.
> >
> > And keep it cool so it won't glaze. Full rich or close to it, cowl
flaps wide
> > open.
>
> Actually my concern is not getting it hot. My engine CHT's run about
> 290-300F in the winter and 360-380 in the summer in cruise. I'm afraid
> that won't be enough to get a good seating.
>
>

[Blueskies]

"Robert M. Gary" > wrote in message oups.com...
>I just replaced a cylnider in my IO-360 with a new cylinder kit from
> Lycoming. Where can I find the service instructions on how to
> correctly break the cylinder in?
>


http://www.lycoming.com/support/publications/service-instructions/pdfs/SI1427B.pdf

http://www.lycoming.com/support/publications/service-instructions/pdfs/SI1014M.pdf
(see specifically bottom of page 2)

[Dan Luke[_2_]]

"Robert M. Gary" wrote:

>> And keep it cool so it won't glaze. Full rich or close to it, cowl flaps
>> wide
>> open.
>
> Actually my concern is not getting it hot. My engine CHT's run about
> 290-300F in the winter and 360-380 in the summer in cruise. I'm afraid
> that won't be enough to get a good seating.

Heat is NOT what seats the rings. Simple wear does it.

Keep your new cyl. cool or it'll glaze and you'll have to have it re-hatched.

--
Dan
T-182T at BFM

[Morgans[_2_]]

"Dan Luke" > wrote

> Heat is NOT what seats the rings. Simple wear does it.
>
> Keep your new cyl. cool or it'll glaze and you'll have to have it
> re-hatched.

But what I read says pressure is what does it, and letting the engine get
too cool is very bad, too.
--
Jim in NC

[Dan Luke[_2_]]

"Morgans" wrote:

>
>> Heat is NOT what seats the rings. Simple wear does it.
>>
>> Keep your new cyl. cool or it'll glaze and you'll have to have it
>> re-hatched.
>
> But what I read says pressure is what does it, and letting the engine get
> too cool is very bad, too.

Yes, high pressure is required to force the rings against the cylinder walls.
That is why break-in is done at high power.

I've never read that too cool is a problem; I've read in several places that
too hot will glaze the cylinders.

--
Dan
T-182T at BFM