Ring Gap?
+ Reply to Thread
Page 1 of 4 1 2 3 4 LastLast
Results 1 to 14 of 55

Thread:
Ring Gap?

  1. #1
    Senior Member XClutchboy725's Avatar
    Join Date
    Apr 2008
    Location
    Alta Loma, CA
    Posts
    436

    Default Ring Gap?

    I'm going to be ordering and building a Dart 540 shortblock. Finish bore will be 4.501 and using SRP Pistons. Compression ratio will be around 10.5:1

    Question is: What formula should I use for ring gap?

    The motor is going in a jet that will see a constant cold water supply.
    Last edited by XClutchboy725; 06-09-2008 at 01:41 PM. Reason: added text

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,975

    Default

    Quote Originally Posted by XClutchboy725 View Post
    I'm going to be ordering and building a Dart 540 shortblock. Finish bore will be 4.501 and using SRP Pistons. Compression ratio will be around 10.5:1

    Question is: What formula should I use for ring gap?

    The motor is going in a jet that will see a constant cold water supply.
    I use .0045 X BORE for everything, may be a little big for a N/A, but it allows you to throw some NOS at it later



    100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

  4. #3
    E-7 Sheepdog (ret) SmokinLowriderSS's Avatar
    Join Date
    Dec 2007
    Location
    Newton Ks.
    Posts
    6,834

    Default

    That ballparks to .020", and that should be just fine.
    "As democracy is perfected, the office of president represents, more and more closely, the inner soul of the people. On some great and glorious day the plain folks of the land will reach their heart's desire at last and the White House will be adorned by a downright moron."
    H.L. Mencken

    OBAMA: Some people deserve this.
    The rest of us are being dragged along kicking and screaming.

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,975

    Default

    alot of it has to do with where the piston company puts the top ring, and the material of the piston. SRP 10 1/2 are 4032 with the ring a little ways down and I have had no problems with .0045. JE's 2618 and USUALLY have the ring a little higher and may need .0050. Kieth Black (FORGED) are 2618 but have the top ring way down and have run them as tight as .004 with no problems. If you are spraying NOS and a JE 2618 you may very well have to go to .0052 Coating the tops of the pistons also allows you close the gaps a wee bit.



    Also, the latest thinking with ring gaps is to open the second ring a couple thousands more than the top ring. This helps to keep pressure from building up between the rings and unseating the top ring.



    100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

  7. #5
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,975

  8. #6
    Senior Member XClutchboy725's Avatar
    Join Date
    Apr 2008
    Location
    Alta Loma, CA
    Posts
    436

    Default

    Thanks guys, that helps. SRP is all over the board on their website...

    http://www.jepistons.com/dept/tech/d...instrc4032.pdf

  9. #7
    Senior Member ol guy's Avatar
    Join Date
    Mar 2008
    Location
    Lake Elsinore Ca
    Posts
    3,840

    Default

    Hey X, Rule of thumb IS .004 per inch of bore. Just do the math. M

  10. #8
    mo balls than $cents$ IMPATIENT 1's Avatar
    Join Date
    Dec 2007
    Location
    hugo,okla
    Posts
    11,733

    Default

    Quote Originally Posted by SmokinLowriderSS View Post
    That ballparks to .020", and that should be just fine.
    arron, you better keep your nitrous turned down low if that's your gaps i think i ended up at 35 top and 26 on the 2nd ring, using je nitrous rings.

  11. #9
    Senior Member stix818's Avatar
    Join Date
    May 2008
    Location
    Mohave Valley/Quartzsite
    Posts
    4,188

    Default

    GN7, Oh, I didn't think it was necessary!! I have a tendency to chyme in when I shouldn't. I'm just a rookie in this business and still learning!!

    I'm not sure what you caught of it but I was talking with the main machinist at Eaton's this weekend and he said a cylinder showed signs of end gaps to tight. It's interesting because we've always ran them about .020" or so with these big bores. Not sure if switching from external cooling to internal would change that much but it may have!! He said (Total Seal agrees) he recommends opening them up to .024". He also mentioned that they haven't seen hardly any change from .024" to .030" so I'm going to open them up a bit when I reassemble the motor. I know that I had to much timing in it and it showed signs of pre-ignition on the piston which will show the same scoring on the wall as tight end gaps, for the most part. We knew it may hurt the motor but we didn't have enough time to change props. Lesson learned!!! Sad thing is I ended loosing a lifter bore so my weekend was over anyways!!
    http://www.performanceboats.com//signaturepics/sigpic3592_1.gif
    Special Thanks to:
    Nelson Speed & Marine
    D21 ENT
    J.J. @ Beaver Fab
    Performance Boat Candy

  12. #10
    Just another Wannabe Wannabe's Avatar
    Join Date
    Jan 2008
    Posts
    1,187

    Default

    Just my personal opinion, but;
    A little looser is always better than tighter. Boats run more cylinder to piston clearance because of the cool water not allowing the block to grow like in an automobile application. You need to adjust the rings a wee bit as the standard gap is set for the bore a touch larger than you will see pulling in cold lake water. And I am a big fan of cutting the second ring 4-6 thou larger to keep away from top ring flutter. Also, you failed to tell us of the fuel. I am guessing gasoline?

  13. #11
    Steady Rollin
    Join Date
    Feb 2008
    Location
    Corona
    Posts
    1,067

    Default

    What kind of gaps would you be looking at with a run of the mill high 400 low 500 cube supercharged lake motor? Sub 12 lbs of boost on maybe 8.5 cr

  14. #12
    Senior Member stix818's Avatar
    Join Date
    May 2008
    Location
    Mohave Valley/Quartzsite
    Posts
    4,188

    Default

    Wannabe, that's what's interesting because I actually went the other way, now I'm running a closed system. Regardless I'm going to make some adjustments!! Can't imagine this thing on all eight!! Not sure if your referring to me about the fuel usage but ya Gasoline.
    http://www.performanceboats.com//signaturepics/sigpic3592_1.gif
    Special Thanks to:
    Nelson Speed & Marine
    D21 ENT
    J.J. @ Beaver Fab
    Performance Boat Candy

  15. #13
    gn7
    gn7 is offline
    Senior Member gn7's Avatar
    Join Date
    Jan 2008
    Posts
    25,975

    Default

    Quote Originally Posted by ol guy View Post
    Hey X, Rule of thumb IS .004 per inch of bore. Just do the math. M
    I can GAR-ON-TEE that if you gap them at that and hit the sneeze for any period of time you will not only butt the rings, but may actually wedge them in the bore and tear the piston apart. Seen it, not pretty.



    100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

  16. #14
    E-7 Sheepdog (ret) SmokinLowriderSS's Avatar
    Join Date
    Dec 2007
    Location
    Newton Ks.
    Posts
    6,834

    Default

    Quote Originally Posted by IMPATIENT 1 View Post
    arron, you better keep your nitrous turned down low if that's your gaps i think i ended up at 35 top and 26 on the 2nd ring, using je nitrous rings.
    She's plenty happy on Speed Pro Molly. LMAO.

    I don't run big Nitrous like you do, only 150HP max.

    Cast pistons.
    "As democracy is perfected, the office of president represents, more and more closely, the inner soul of the people. On some great and glorious day the plain folks of the land will reach their heart's desire at last and the White House will be adorned by a downright moron."
    H.L. Mencken

    OBAMA: Some people deserve this.
    The rest of us are being dragged along kicking and screaming.

+ Reply to Thread
Page 1 of 4 1 2 3 4 LastLast

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