Engine management

[Thomas]

It's probably more related to quick cooling. Your car has water around the cylinders keeping temp constant. I was taught from my first flying lesson not to pull back the throttle rapidly. So far I've only overhauled my engines once. I have always bought airplanes with runout engines & overhauled them. The only time I didn't was a Comanche with a 500 hr engine. It came apart 30 days after I bought it. Kit #140 will be my first new engine.

Volkswagen, Porsche, Motorcycles all air cooled, or were.?

[Smiddo]

I have been helping a friend with his new CC EX and here are my questions with the break in. The engine has around 50 hours at this time and from the beginning the oil turns jet black after about 4-5 hours of use. We have changed the oil around 4 times since new. Also (I realize we are at 4000') but the engine will hardly run with the mixture full rich. Im talking the need to pull the mixture out 1.5" in order to achieve takeoff power. Otherwise a kick in the pants airplane.

[DRL]

I have been helping a friend with his new CC EX and here are my questions with the break in. The engine has around 50 hours at this time and from the beginning the oil turns jet black after about 4-5 hours of use. We have changed the oil around 4 times since new. Also (I realize we are at 4000') but the engine will hardly run with the mixture full rich. Im talking the need to pull the mixture out 1.5" in order to achieve takeoff power. Otherwise a kick in the pants airplane.

That mixture setting sounds about right. We are at sea level and start leaning aggressively between 2 and 3 thousand feet. On our initial flights we thought we had a problem. Above 5T, with full rich, full power, it would run very rough. A call to Cubcrafter and they said to lean it out, no problems after we did that and started paying attention to EGT. It seems this is an issue with carburetors. The fix is fuel injection, and it has been suggested here, but the expense and weight may not be worth it on a Cub.

If the engine is running rich, it could turn the oil black, but there may also be other reasons. Ours stays clean, but we have had other engines that oil turned black and there were no problems.

[Jon Delamarter]

Don't count on on oil analysis. All of mine including the one we did when we found the bad cylinders came back clean.

Agreed. Years ago, I had a customer with a Mooney M20J with an engine that ran rough at idle. Turns out he had a cam lobe that was so far gone it was almost round. He had pulled an oil sample religiously at every oil change, with the analyses offering no sign of impending cam failure.

Oil analysis can be very useful, if it is properly understood as only one of multiple tools that a mechanic has at their disposal to evaluate your engine's health.

Oil analysis is just one tool your mechanic had at his disposal to diagnose your engine.


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[lbell]

Volkswagen, Porsche, Motorcycles all air cooled, or were.?

Good point. But they don't have 100 mph wind hitting them when you drop the throttle

[Cubrath]

Good point. But they don't have 100 mph wind hitting them when you drop the throttle

Here re is a good article on the old wifes' tale of the propeller driving the engine problems. Unless you have a P&W radial you don't need to be to concerned. Imagine how many O-320's in the training environment would be destroyed on a daily basis if driving the propeller was truly a big problem.

http://www.avweb.com/news/pelican/186778-1.html

[kiwibob]

The shop found one cylinder with very low compression.
It was removed after borscoping and we found that the second ring was badly damaged as was the piston groove and the cylinder wall was scored.

Hi Bill

I wondered if this cylinder was the same one that you reported in 2012 had the lower EGT that the others?.

I also wondered if you had ever installed the vernatherm to get the oil temperature up? You mentioned in an early post that you had trouble with low oil temps.

Cheers

[seastar]

KIWIBOB
Nope it was the #4 that always ran cold. #1 ran the hottest And 2&3 in the middle.
yes I had a vernatherm installed and the oil ran/runs at 180 to 195 all the time.
bill

[seastar]

Here re is a good article on the old wifes' tale of the propeller driving the engine problems. Unless you have a P&W radial you don't need to be to concerned. Imagine how many O-320's in the training environment would be destroyed on a daily basis if driving the propeller was truly a big problem.

http://www.avweb.com/news/pelican/186778-1.html

It's NOT an OWT according to both ECI and Lycoming techs.
You can find any answer you want on the Internet.
Bill

[Cubrath]

It's NOT an OWT according to both ECI and Lycoming techs.
You can find any answer you want on the Internet.
Bill

I thought it was a pretty good article based on some facts from a respected aviation writer.

I wonder if it is such a big issue why more lycoming and ECI operators don't have problems. The University flight school I worked at back in the day operated over 100 Lycomings. You think they would have banned emergency decents if it was such a big issue. If that wouldn't cause ring flutter I don't know what would. A vast majority of those engines went hundreds of hours past TBO.

I'm not saying it can't happen, I'm just saying that it obviously isn't a wide spread problem.