The mechanics I've used over the years, and the factory reps I've talked to, all seem to be pretty unanimous in saying one should run those Continental engines as hard and as often as you can. To meet certification, those engines are test run at redline for TBO hours, and they look like new inside when they tear them down.

The O-300 in my C172TD, which is just a C-85 with a couple more jugs, runs at 2,550 to 2,650 RPM here in Nevada. At the altitudes I'm forced to fly here, cruising with lower RPM just makes the airplane mush along. I've put about 500 hours on this engine in the two years I've had it, and it seems happy as a clam. Fuel flow doesn't really change. It likes just a hair less than 8 GPH no matter what I do.

Gump

N6EA wrote:For all the talk about fuel, it's really the cheapest thing about aviation, even at today's prices.

On a per hour basis fuel is almost certainly your most expensive part of flying. It's even more expensive than insuring a Maule.

I heard about an O-300 powered Swift pilot who ran his
engine WOT from take-off until approach to land so he could
keep up with his higher-horsepowered Swift friends when they
went flying together. Didn't seem to hurt a darned thing....

The TCDS for my old C-145 powered C-170 just specifies:
"Engine Limits - For all operaions, 2700rpm (145hp)."
I used to run the 170 at 2600rpm to keep the comments
to a dull roar from the guys I was flying it with ("you're too
damned slow...", "we'll never get there", "the trucks are
passing us on the freeway", etc.).

I run the O-470J in my 180 at 22 squared when I can get
the manifold pressure, and she'll do 142-ish mph down low,
and close to (or right at) 160mph up high while drinking about
13gph (I currently only have an Alcor EGT plumbed to the #2
exhaust stack, so I don't lean agressively).

While cruising up high, I also use WOT minus a wee bit to get the
throttle plate backed off a bit and also to get out of the power
enrichment valve.

When farting around down low with nowhere to go (just up
for a fun/sunny day of local flying), I'll run the 180 at what I call
"170 speed" (18 inches and 2000rpm) which gives me about
125mph of speed and about a 9gph fuel burn.

Was following a friend home last summer in his newly purchased
Luscombe, and it took about 12 inches of MP at 2200 rpm to
stay with him, and the O-470J burned about 6gph (less than
the Luscombe did with it's Stromberg carburated / safety-wired
full-rich C-85!).

1954C180 wrote: O-300 powered Swift pilot who ran his engine WOT from take-off until approach to land. Didn't seem to hurt a darned thing....

That's my thinking. The worn valve guides, poor ring seating, and a whole lotta other kind of ugly all seem to be from not running these engines hard enough, or frequently enough. Paying for a bit more gasoline is a known entity. The cost of fixing cylinders is not.

Gump

Bonanza Man wrote:

N6EA wrote:For all the talk about fuel, it's really the cheapest thing about aviation, even at today's prices.

On a per hour basis fuel is almost certainly your most expensive part of flying. It's even more expensive than insuring a Maule.

Not if you your going to include the cost of the aircraft, hangar, insurance, maintenance, etc. An easy example is what is being charged to rent a 172 wet. Is the fuel cost per hour more or less than 1/2 the rate???

I’ve always feared that I might be an Alzheimer’s candidate, and it must be getting close.

What is WOT? Wide open throttle, or Wild old timer??

Costs differ among us. I don't insure, I'm an IA, get free hangar space, etc. Fuel is by far my biggest expense, it's why auto fuel STC's are so popular. Fuel is about the only expense we have some control over by flying less.

patrol guy wrote:I’ve always feared that I might be an Alzheimer’s candidate, and it must be getting close.

What is WOT? Wide open throttle, or Wild old timer??

Another way of saying WOT was WFO

N6EA wrote:" What's the difference between a grump and a gump ?"

Not a whole lot as far as I can tell...

Gump

a64pilot wrote: Another way of saying WOT was WFO

As opposed to saying "WTFO"

I seem to say that a lot most days. That compliments my "deer in the headlights" look.

Gump

I gotta agree with everyone saying not to baby engines,... at least low compression ones.

I taught seaplanes for several years in Central California. We were running several different aircraft at redline for at least half their life, many times OVER redline if the student didn't pull the power back quick enough. Running a fixed pitch prop pitched to where you lift off the water pushing redline is just a way of life if you wanted to get off the water at 90 degrees OAT in the Sierra foothills, or in the highcountry at all. Those engines ran 800 hours a year on average and ALL made TBO, even on autofuel. No TOPs, cracked cylinders, etc.

We even had a O235 on a SuperCub that ran to 2300 hours with compression in the 70's and only burning a quart of oil every 25 hours before we figured we should overhaul it just to be safe. After doing that for years, it convinced me.

There is ALOT of old-wives-tales in aviation.

Now this has to be one of the most useful threads I've read.

You all are loads of information, and I appreaciate your wisdom and the fact that it's shared willingly.

Nothing beats learning from the more experianced pilots that have been there and done that. Unless hearing it in person over a cold beer and camp fire

Thank you! Bub

Skylane wrote: Unless hearing it in person over a cold beer and camp fire

Bub, you mean like a unsponsored, fully BCP sanctioned, interactive, multi-topic, field based, seminar and discussion forum ?

My calendar shows I have one on the schedule for June 27 - 29...

N6EA wrote:

Bonanza Man wrote:

N6EA wrote:For all the talk about fuel, it's really the cheapest thing about aviation, even at today's prices.

On a per hour basis fuel is almost certainly your most expensive part of flying. It's even more expensive than insuring a Maule.

Not if you your going to include the cost of the aircraft, hangar, insurance, maintenance, etc. An easy example is what is being charged to rent a 172 wet. Is the fuel cost per hour more or less than 1/2 the rate???

Take each item individually and what do they cost per hour? The only thing that approaches fuel is the cost of the note, if you have one. Possibly a hangar if you live in an expensive area.

N6EA wrote:

Skylane wrote: Unless hearing it in person over a cold beer and camp fire

Bub, you mean like a unsponsored, fully BCP sanctioned, interactive, multi-topic, field based, seminar and discussion forum ?

My calendar shows I have one on the schedule for June 27 - 29...

Yeah, That's what I'm talking about.

C ya, Bub