Continental O-300 longevity

Can an 0-300 last a long time?

I just bought into a C-172 with an O-300, approx 700 SMOH. It is down
for an annual and we have discovered #2 and #4 cylinders have sticky
valves. One of the valves will need to be replaced.

Surely there is a time-tested set of techniques somewhere on how to
maximize the life of these motors.

We do all the standard things - gentle starting, conservative leaning,
gradual power changes, proper oil changes, minimized idling, fly it
frequently, etc.

What are the "special" things that this motor likes in order to last a
long time? We are wondering about leaning techniques, autogas (it has
the STC but has been using 100LL), valve guide set-up, carb setup,
additives, etc.

Thanks for any info.

P. S. -- Don't tell me about MMO. One of my flying buddies is a
chemical engineer for Shell. MMO is nothing but kerosene and some
other solvent mixed with dye and perfume. Besides, it is illegal. He
suggested that if anyone could not resist putting oil in their gas,
they should put in a slight amount of synthetic 2-stroke oil. It
provides a moderate lube at very thin dilutions and very high temps,..
and it burns very cleanly -- no carbon. Also illegal.

Mel wrote:



We do all the standard things - gentle starting,

What does this mean...you whisper sweet nothings into your headset while
cranking?

Read the thread "Does Avblend work"

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

"Mel" wrote in message
oups.com...
Can an 0-300 last a long time?

I just bought into a C-172 with an O-300, approx 700 SMOH. It is down
for an annual and we have discovered #2 and #4 cylinders have sticky
valves. One of the valves will need to be replaced.

Surely there is a time-tested set of techniques somewhere on how to
maximize the life of these motors.

We do all the standard things - gentle starting, conservative leaning,
gradual power changes, proper oil changes, minimized idling, fly it
frequently, etc.

What are the "special" things that this motor likes in order to last a
long time? We are wondering about leaning techniques, autogas (it has
the STC but has been using 100LL), valve guide set-up, carb setup,
additives, etc.

Thanks for any info.

P. S. -- Don't tell me about MMO. One of my flying buddies is a
chemical engineer for Shell. MMO is nothing but kerosene and some
other solvent mixed with dye and perfume. Besides, it is illegal. He
suggested that if anyone could not resist putting oil in their gas,
they should put in a slight amount of synthetic 2-stroke oil. It
provides a moderate lube at very thin dilutions and very high temps,..
and it burns very cleanly -- no carbon. Also illegal.


Burn mogas if possible and if you need to run that 100LL crap use TCP. The
small Continentals, your O-300 is an O-200 with two additional cylinders,
don't run hot enough to scavenge the lead in 100LL. They were designed for
70 some octane lead free fuel.

Then tell your buddy to overhaul your engine. It's amazing. The airlines
(back in the piston days) bought MMO by the 55 gallon pallet truckload to
keep their engines running smooth.

Take your buddy and stuff him up your exhaust pipe. Also take your buddy
and wipe the lead from your cylinders on his shirt from your 100LL diet.
Use Mogas or quitcherbitchen.

Jim




P. S. -- Don't tell me about MMO. One of my flying buddies is a
chemical engineer for Shell.

On 15-May-2005, "Mel" wrote:

We do all the standard things - gentle starting, conservative leaning,


What do you mean by "conservative" leaning. To survive on a diet of 100 LL
these engines need to be leaned AGGRESSIVELY to minimize the amount of lead
that has to be scavenged. This includes leaning during ground operations to
the leanest mixture that will allow the engine to run smoothly. Full rich
should probably be used only during sea level (or near sea level) takeoff
and initial climb.
--
-Elliott Drucker

I've owned five planes with small Lycomings and Continentals. I fully
agree with what the others have said. Leaning on the ground and in the
air, burning mostly auto gas, and using MMO is the way to go. But I'll
add one more -- FLY REGULARLY! Try to not let that engine sit idle for
more than three or four days if you can. The engines that last the
longest are the ones that are run just about every day.

- Brett

What does this mean...you whisper sweet nothings into your headset
while
cranking?

How clever.

Gentle starting means knowing the throttle settings well enough so that
when the engine starts it revs up to about 800 rpm or so and stays
there.

Are you not bothered by the common hi-wear technique (instantly revving
to 2000 rpm as soon as the engine starts to fire, then throttling back
down) that a lot of mental midgets use?

Mel wrote:
Can an 0-300 last a long time?


Autogas will be your best bet. The O-300 is particularly bad at
scavenging the excess lead in 100LL. Deposits tend to end up on the
valves and sticking is common.

I used to fix about 1 stuck valve per year while burning 100LL in an
O-300. Switched to autogas and the problem disappeared completely.

John Galban=====N4BQ (PA28-180)

....and keep the baffles in good shape.