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  1. #1
    Senior Member Dan L's Avatar
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    Default compression test

    It has been a year since I was issued my Airworthiness Certificate and I'm in the process of performing my first Condition Inspection. In checking the compression using a differential tester with an inlet pressure dialed to 80 PSI my cylinders are checking excellent. Three of them are 78 and one is 77.

    I'm wondering how this compares to other engines with similar hours? I have 126 hours now. I broke the engine in running Aeroshell straight-weight mineral oil for the first 25 hours. I changed it after about the first ten hours and put in the same oil up to the 25 hour change. I ran it hard these first hours too. Following that I changed oil each 25 hours using Phillips 20-50 XC oil and after 100 hours added a half quart of Camguard with the same Phillips oil.

    Just a few little things found during the inspection. I tighened the alternator belt, found that the plastic oil filler neck was loose and kept from rotating by safety wire and a re-solder of two primer fitting to the copper line. I have three injectors for the primer system and prefer to use it rather than use the accelerator pump in the carb to start when cold.

    I'm really pleased with the CC O-340 engine.
    Flying Carbon Cub EX #11 since 2011

  2. #2
    Senior Member randylervold's Avatar
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    Default Re: compression test

    Dan, everything you indicate sounds competely normal. I'd say you have a very healthy engine and have cared for it correctly. You may know that we (and ECi) recommend the Philips 20w-50 AD right from the beginning. AeroShell non-AD works fine too. Adding the CamGuard after the engine is broken in provides superp anti-wear and anti-corrosion properties so that is recommended also but of course adjust the quantity to half a bottle based on the lower oil capacity of the CC340. You've probably seen it but I posted a 'sticky' on oil in the Carbon Cub SS section here.
    Randy Lervold

  3. #3
    Senior Member Dan L's Avatar
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    Default Re: compression test

    Thanks Randy. It is a great engine. I'm also impressed with the low fuel burn.

    I missed you at Ryan's last week. I came Saturday morning in the Carbon Cub. Those of us left Saturday night listened to live Bluegrass music and then thunderstorms pounding our tents.

  4. #4
    Senior Member Paul's Avatar
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    Default Re: compression test

    Quote Originally Posted by Dan L View Post
    I checked my compression again. There are 360 hours on it now and all four cylinders checked 78. Perfect.

    image.jpg

    Sluice Creek on the Oregon side of Hells Canyon in early March.
    Good news Dan. And nice pIc. It was cool to read this post from almost a year ago with my CC340 sitting in Yakima...and fast forward today it has 50 hours of perfect performance in Arizona skies.

  5. #5
    Senior Member Dan L's Avatar
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    Default Re: compression test

    Boy this is a great engine. I'm a couple of hours under 200 on it now and did a compression test last week. Each cylinder was 79/80.

    At low power settings I'm a pretty aggressive leaner too. I topped of over the weekend and put in 39 gallons and had flown 8.1 hours since the last fill up.

    Here's Moose Creek Idaho from the weekend
    Attached Images Attached Images
    Last edited by Dan L; 04-02-2013 at 07:51 PM. Reason: Added image and fuel comment
    Flying Carbon Cub EX #11 since 2011

  6. #6
    Senior Member randylervold's Avatar
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    Default Re: compression test

    Quote Originally Posted by Dan L View Post
    Boy this is a great engine. I'm a couple of hours under 200 on it now and did a compression test last week. Each cylinder was 79/80.

    At low power settings I'm a pretty aggressive leaner too. I topped of over the weekend and put in 39 gallons and had flown 8.1 hours since the last fill up.
    You must have broken the engine in correctly, are taking care of it with frequent oil changes, and using good operating habits. Also, ECi has perhaps the best cylinder technology available, more info HERE. Of course electronic ignition helps with the combustion efficiency as well. Nice when everything comes together and works, huh?
    Randy Lervold

  7. #7
    Senior Member Dan L's Avatar
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    Default Re: compression test

    Since I've been making a report on this each year, I checked my compression again and am keeping it going. Still showing high numbers after 626 hours. Three 78s and a 77.

    image.jpg

    Yesterday afternoon. Even as low as the river there is plenty of snow in our valley. Sans snowshoes this area would let me sink to my thighs. These Carbon Concept carbon fiber skis really float well in the loose snow and provide a lot of AOA.
    Flying Carbon Cub EX #11 since 2011

  8. #8
    Senior Member Dan L's Avatar
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    Default Re: compression test

    I bumped my Condition Inspection up a month and part of that is a compression test. With 525 hours on the O-340 now they still check excellent with three 78s and a 79.

    image.jpg

    This is last week up the North Fork of the Flathead.
    Flying Carbon Cub EX #11 since 2011

  9. #9
    Senior Member Centmont's Avatar
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    Default Re: compression test

    Dan: I'm shocked there is that little snow. Our mountains are still covered and we are expecting more in the next day or two. Can I come over and Play? Ralph
    Ralph Rogers
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    CCSS #142 N123MR
    I have always felt the supercub is one thing mankind got right the first time but that there were better materials and methods to build them. CubCrafters products are proof I was right.

  10. #10
    Senior Member Dan L's Avatar
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    Default Re: compression test

    Quote Originally Posted by Centmont View Post
    Dan: I'm shocked there is that little snow. Our mountains are still covered and we are expecting more in the next day or two. Can I come over and Play? Ralph
    Hi Ralph, keep in mind Moose Creek is only 2500' or so. Here's a picture of Fish Lake the same day. Well I guess not, the file was too large to upload I was told. Anyway lots of snow up high. We had snow here in the valley Monday of this week.
    Flying Carbon Cub EX #11 since 2011

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