Oil Rings
Results 1 to 8 of 8

Thread:
Oil Rings

  1. #1
    Junior Member skier207's Avatar
    Join Date
    May 2013
    Posts
    6

    Default Oil Rings

    I am building a BBC engine (roughly 500hp) for my sterndrive boat I am using Speedpro rings have file fitted the compression and second rings to .022 end gap for 4.281 bore when I check the oil rings they are @ .035 out of the box don't seem right, I have looked and every reference I find shows the oil ring gaps being in the range of .014 -.018. I searched through this forum and found nothing (probably there just cant find it) on oil ring gaps Anyone have any opinion on this?

    Thx
    Quick reply to this message Reply  

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Village Idiot fc-Pilot's Avatar
    Join Date
    Jan 2008
    Location
    Peoria, AZ
    Posts
    3,268

    Default

    Most ring sets I have used has similar findings. I can't remember off the top of my head what they measured out at (I have it in all the notes and specs on each of my builds), but for basic performance stuff I have never worried about in, and never had a problem. Give the ring manufacturer a call and ask them directly. A phone call is valuable here.

    Paul
    Quick reply to this message Reply  

  4. #3
    Some guy obnoxious001's Avatar
    Join Date
    Dec 2007
    Posts
    3,568

    Default

    Quote Originally Posted by skier207 View Post
    I am building a BBC engine (roughly 500hp) for my sterndrive boat I am using Speedpro rings have file fitted the compression and second rings to .022 end gap for 4.281 bore when I check the oil rings they are @ .035 out of the box don't seem right, I have looked and every reference I find shows the oil ring gaps being in the range of .014 -.018. I searched through this forum and found nothing (probably there just cant find it) on oil ring gaps Anyone have any opinion on this?

    Thx
    I don't think that should be an issue. Ring gaps are always given a "minimum", including oil rings. I always check for .015 minimum, and make sure the are square, as the oil rings are flimsy and may not want to stay in one place when you use a feeler gauge.
    Quick reply to this message Reply  

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Senior Member ol guy's Avatar
    Join Date
    Mar 2008
    Location
    Lake Elsinore Ca
    Posts
    3,811

    Default

    I worked and was a salesman for sealed power and speed pro. The ss50u oil ring was the best ring you can have. They are set at a gap to allow the ring to "ratchet" or spin to keep the bore clean and return oil to the pan to let the compression rings do there job. Just remember to clock your;e ring gaps. M
    Quick reply to this message Reply  

  7. #5
    Senior Member bville's Avatar
    Join Date
    Sep 2009
    Location
    Glasgow, KY
    Posts
    1,686

    Default

    The thing about ring gap is if you are anywhere close on wide side your ok.But if your even 1 thousand to tight, or in other words the ring ends touch when the engine is running your in a world of hurt.To answer your question .035 on the oil on ring would not bother me one bit,as mentioned before make sure the gaps do not line up.
    Last edited by bville; 04-11-2017 at 09:50 AM.
    Quick reply to this message Reply  

  8. #6
    Junior Member skier207's Avatar
    Join Date
    May 2013
    Posts
    6

    Default

    Thanks everyone for all the input.

    I did talk to Federal Mogul the rep told me that the gap range is .015 - .045. While .035 isn't the max I just don't care for being on the big end of any clearance when building an engine. I am going to put it together and see how it goes. An interesting thing that came up in conversation with the rep was (I read this in the instructions also) Speed Pro recommends running the second ring gap wider than the top ring. According to Speed Pro the top ring's job is to seal compression/combustion and the second ring is mainly oil control their wider gap theory is it would prevent a pressure build up between the first and second ring that might unseat the the top ring and cause blowby.
    Quick reply to this message Reply  

  9. #7
    Senior Member bville's Avatar
    Join Date
    Sep 2009
    Location
    Glasgow, KY
    Posts
    1,686

    Default

    Quote Originally Posted by skier207 View Post
    Thanks everyone for all the input.

    I did talk to Federal Mogul the rep told me that the gap range is .015 - .045. While .035 isn't the max I just don't care for being on the big end of any clearance when building an engine. I am going to put it together and see how it goes. An interesting thing that came up in conversation with the rep was (I read this in the instructions also) Speed Pro recommends running the second ring gap wider than the top ring. According to Speed Pro the top ring's job is to seal compression/combustion and the second ring is mainly oil control their wider gap theory is it would prevent a pressure build up between the first and second ring that might unseat the the top ring and cause blowby.
    Yep we call the second the scraper ring or oil off ring.lower ring puts oil on 2nd ring takes oil off.
    Quick reply to this message Reply  

  10. #8
    Village Idiot fc-Pilot's Avatar
    Join Date
    Jan 2008
    Location
    Peoria, AZ
    Posts
    3,268

    Default

    Quote Originally Posted by skier207 View Post
    Thanks everyone for all the input.

    I did talk to Federal Mogul the rep told me that the gap range is .015 - .045. While .035 isn't the max I just don't care for being on the big end of any clearance when building an engine. I am going to put it together and see how it goes. An interesting thing that came up in conversation with the rep was (I read this in the instructions also) Speed Pro recommends running the second ring gap wider than the top ring. According to Speed Pro the top ring's job is to seal compression/combustion and the second ring is mainly oil control their wider gap theory is it would prevent a pressure build up between the first and second ring that might unseat the the top ring and cause blowby.
    All true. The good ring sets have a napier second ring and that design does an even better job of getting excess oil off the wall that the oil ring leaves behind. We have been gapping our second rings the same or larger (depending on the individual application) than our top rings for 20 years or so. I know pro engine builders have been doing it even longer. I have a feeling you will not have any problems due to having that oil ring gap. Good luck and keep up posted on how it runs.

    Paul
    Quick reply to this message Reply  

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in

Tags for this Thread

Digg This Thread

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95