Register

If this is your first visit, please click the Sign Up now button to begin the process of creating your account so you can begin posting on our forums! The Sign Up process will only take up about a minute of two of your time.

Results 1 to 4 of 4

  1. #1

    Join Date
    Jan 2011
    Location
    Barneveld, NETHERLANDS
    Posts
    2
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    Brand new RCV58-CD, feels like having slack on cranckshaft

    Hello All,

    After a "pause" of 30 years I started modelflying again last year. I put my trainer through its excercises and enjoyed it a ton!.For this yearI optfor a nice 4-stroke in the nose of my plane. After researching the internet I decided that the elegance of the RCV engine is just what I want.

    I received my engine today from Weston in the UK and while examining the engine I noticed that it feels like the engine has slack inside. I can turn the propdriver about 3 degrees left-right without feeling any resistance from the engine.The rotating valve does not move then. At both ends I hear and feel a soft "clunck" and then the valve starts to rotate. Like a lot of slack in the gears between cranckshaft and rotating valve. But I would expect at least to feel resistance from a brand new piston in the cylinder, but to be honest, I dont feel that.

    If I compare the feeling with a 2 stroke engine, it feels like a 2 stroke with a completely worn out big-end.

    Now my newbee question is ofcourse "is this normal and the case with all RCV 58 CD engines? Or do you fellow RCV owners don'tfeel this in your engine, which would mean I better not try to start the engine.

    Best regards,
    Hans Meijdam
    The Netherlands

  2. #2

    Join Date
    Jun 2002
    Location
    Hartsville, SC
    Posts
    148
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Brand new RCV58-CD, feels like having slack on cranckshaft

    Hans

    I am no expert on RCV but have been running my 120SP extensively lately and have the same "Slack". I think that what you feel is actually the Backlash which is the correct engineering term for the amount of controlled play between the gear teeth. Since the rotating barrell is geared 1:2 in the case of the CD, it feels like a lot of "Slack" but is actually normal. My 58CD feels about the same. I would suggest that you go ahead and break it in, you will probably love it.

    Joshua

  3. #3
    mboland's Avatar
    Join Date
    Jul 2007
    Location
    BouldercombeQueensland, AUSTRALIA
    Posts
    558
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Brand new RCV58-CD, feels like having slack on cranckshaft

    I have just checked the two 58CD's I have and each has about 1deg of 'slop' evident when cold.

    Both engines have been sitting for some time and both have had a lot of running in the past.

    3deg does sound a bit much.

    Have you contacted the suppliers. That would be the place to start.
    RCV's customer support was unparalleled and I have heard Weston UK are just as good.
    An email to them personally might get you some good advice on whether it is OK to run the engine.


    It\'\'s the quality of life that counts, not the quantity.

  4. #4

    Join Date
    Jan 2011
    Location
    Barneveld, NETHERLANDS
    Posts
    2
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: Brand new RCV58-CD, feels like having slack on cranckshaft

    Hi all,

    Thanks for your prompt responses and taking the effort to compare with your engines. I did mail to Weston-UK yesterday as well, so I will wait for their response. I am intending to start-up the engine over the next weekend, for some running-in time. I can imagine that the engine needs backlash between the teeth of the 2:1 gear. I was just wondering what is the right amount of backlash. Too little and the teeth will be grinded. Too much and the teeth will be hammered. I found an arc in the meantime, so that I can measure the amount of free rotation of the prop driver as the 3 degrees was my gut-feeling estimate.

    Edit: in the meantime Alan from Weston-UK responded to me as follows:

    This is quite normal because with the CD range you do not run a very tight gear mesh. The motor will run fine, do not worry, start it up, you will be impressed!


    So I will start the running-in as per the instructions in the manual over the weekend.

    Thanks again,

    Hans


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT -6. The time now is 09:14 AM.

SEO by vBSEO 3.6.1 ©2011, Crawlability, Inc.