Hello,

I am looking to make my first purchase, a Cubcrafter Sport Cub. The plane has 850hrs on it. Around 400hrs ago, it had a Ly-con 9.0:1 pistons installed with new cylinders. I am being told that under typical flight conditions it is using a quart of oil every 6 hours. I am told that it has done this since the pistons were installed and that it is common with these. Aside from this issue, I think this will be a great first plane to build some time on. I would really appreciate some thoughts in this regard. The plane is very clean. Thank you in advance to those that can share some knowledge.

Thanks!

Matt

Every engine is different but I would not worry about that amount of oil use at all. DENNY

That is common oil usage with a mid time engine.

Good choice, I have a handful of hrs on one. Amazing what they can do.

Thank you guys for the feedback! One thing I failed to mention was that I was told that it wasn't burning oil, but that it was passing the rings and coming through the breather.

Matt

I have several hundred hours behind a O-200, (not that piston combination), and that doesn't seem out of the ordinary. Also, for a lot of those engines if filled to capacity they will "blow" oil out the breather. I found the sweet spot in mine was 4 1/2 - 5 quarts. Sounds like a fun plane, good luck!

Pete

Thank you Pete, I appreciate the info.

Thank you for the info Pete. I am excited, but proceeding cautiously.

pburns wrote:I found the sweet spot in (my O-200) was 4 1/2 - 5 quarts.

My experience was the same. If I filled it up, I'd be cleaning a quart of oil off the belly. If I let it "settle" at 4 1/2 to 5 quarts, it used very little oil between changes.

Lostgriz wrote:Thank you guys for the feedback! One thing I failed to mention was that I was told that it wasn't burning oil, but that it was passing the rings and coming through the breather.

Matt

I'm familiar with that situation, proceed with caution. Oil will blow out until 1 1/2 qts. at which point the oil pressure drops off. Oil turns black in less than 10 hrs use and oil temps run high.

The quart of oil burn in six hours is with at least one and maybe two quarts below full in the sump. Round engines, because they burned a lot of oil, had five gallons or so in a reservoir. Unlike modern cars, airplane engine oil level has to be monitored closely. We always check the oil before each flight. If you fly for a living, the oil sump will be changed/filled every 100 hour inspection by you or the mechanic. He will not log less and most won't lie. You will have to clean the underside of tail at least every 100 hours.

Crankcase breather improvement
Read about this near the bottom of this link:
https://150cessna.tripod.com/c150o200ainsp.html

If your experimental make your own or contact Bill at this link scroll down to Followup
http://www.bowersflybaby.com/tech/fento ... d_breather

Thank you guys, really appreciate the feedback! I got a chart that shows the "max desirable oil consumption rate" for this engine is .6 quarts per hr..... How is that even close to desirable, lol. Shouldn't this be called "the worst allowable oil consumption rate allowed."

As long as it runs out of gas before oil, you're within the allowable consumption from Continental.

https://mooneymite.org/maintenance/cont ... herfix.htm

This may help if not done yet.

I was looking at purchasing the same/similar type of CC Sport Cub a few years ago. While doing my research, I spoke to an owner of one and he mentioned that the plane he had was very similar in that it had a thirst for oil. Relayed to me that his was that way from new. Seem to recall there was an SB or something to fix possibly the rockers also. Can't recall exactly what it was but something with the valve train. The owners all said they were great performing airplanes though.

[quote="Aryana"]As long as it runs out of gas before oil, you're within the allowable consumption from Continental.[/q uote]

A quick question for you Aryana, what seems to be the sweet spot for oil levels in your 0-300 before it start blow off the excess.

Mapleflt wrote:

Aryana wrote:As long as it runs out of gas before oil, you're within the allowable consumption from Continental.[/q uote]

A quick question for you Aryana, what seems to be the sweet spot for oil levels in your 0-300 before it start blow off the excess.

6 quarts, as is the case with many other O-300's.

Aryana wrote:

Mapleflt wrote:

Aryana wrote:As long as it runs out of gas before oil, you're within the allowable consumption from Continental.[/q uote]

A quick question for you Aryana, what seems to be the sweet spot for oil levels in your 0-300 before it start blow off the excess.

6 quarts, as is the case with many other O-300's.

Agreed, that's what I'm seeing with my engine as well. Cheers

David K, this is very interesting. Have you or anyone here done this and can speak to how it worked?

Thanks!

Matt