Page 1 of 2 1 2 LastLast
Results 1 to 10 of 19

Thread: Compression

  1. #1

    Join Date
    Nov 2005
    Location
    All over
    Posts
    716

    Compression

    OK, so after a good break in on my Lowell ported, head milled engine, I have speed and other stuff to report...

    Well I've hit a 74.5 (Going up in the morning!!! ) with RPMs @ 7110 turning a 15/24 DF.

    I just check my compression and I'm only getting the following...

    1) 125
    2) 132
    3) 125

    I'm going to be email Lowell also, but doesn't this seem way low??? I'm going to pull the head tomorrow and see if there's any sign of problems, but she's running very strong!!! I'm just wondering what I'm missing with that low of compression. It seem about stock maybe a bit higher. If I get the compression up I'm hoping the RPMs will come up a it.

    Any one chime in with info, questions whatever.

    Scott


  2. #2
    Where is the shrader valve in your gauge? If its in the end of the hose that screws into the plug hole your readings will be accurate. It its in the other end of the hose or made in the end of the gauge your readings will always be low on everything you check. The hose volume adds ccs to the head volume when the shrader valve is at the end of the hose instead at the beginning, effectively giving low compression readings...

  3. #3
    r33pwrd's Avatar
    Join Date
    Mar 2006
    Location
    Sammamish Washington
    Posts
    4,216
    +1
    360
    scott we can try your gauge on my ski tommorow and see what ir says! they are pretty even to have a problem (imo) if one was low i would be a little more suspicious! We can also try my friends snap-on gauge that I use on my ski.

  4. #4

    Join Date
    Nov 2005
    Location
    All over
    Posts
    716
    Just check the wifes stock ski and got ~120 across the board... Now I'm no engineer, (wait, I am lol,) but I need to talk with Lowell!!! I'm not sure what he expected the compression to be at but that's too low for the work I had done... I will be pulling the head and checking for damage... Let's hope Lowell was just being very conservetive (under my direction.) "Lowell, you know I don't think I wnat to go crazy..." Anyway, we'll see.

    Saturday will be interesting!

  5. #5

    Join Date
    Jan 2006
    Location
    Texas City, Texas
    Posts
    1,249
    +1
    15
    Quote Originally Posted by RXPkiller
    Just check the wifes stock ski and got ~120 across the board... Now I'm no engineer, (wait, I am lol,) but I need to talk with Lowell!!! I'm not sure what he expected the compression to be at but that's too low for the work I had done... I will be pulling the head and checking for damage... Let's hope Lowell was just being very conservetive (under my direction.) "Lowell, you know I don't think I wnat to go crazy..." Anyway, we'll see.

    Saturday will be interesting!

    Before you go to all of this trouble, check it with another gauge like your bud suggested. Snap-on, Mac etc.

    You yourself said it feels good, trust that.

    Besides, Lowell doesn't make those kinds of mistakes.

  6. #6
    How did you check compression???

    Fully charged battery, remove all wires and 1 plug at the time, wide open throttle, make sure that the threaded part of the gauge that screws into he head has the same lenght as the spark plug .

  7. #7

  8. #8

    Join Date
    Nov 2005
    Location
    All over
    Posts
    716
    Thanks everyone!!! I'll be letting you all know.

  9. #9
    mtrager's Avatar
    Join Date
    Jul 2006
    Location
    Orlando, Florida, United States
    Posts
    2,443
    +1
    2

    Rxp killer

    The same thing happened to me. My guage was trashed.

  10. #10

    Join Date
    Nov 2005
    Location
    All over
    Posts
    716
    Quote Originally Posted by mtrager
    The same thing happened to me. My guage was trashed.
    Hope not... ..it's the first reading I've took with it. Just picked it up last week.

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. How To: Compression Test
    By Red Devil in forum 4-Tec Performance
    Replies: 9
    Last Post: 06-01-2007, 12:05 AM
  2. rxp cylinder compression
    By buddydoo in forum 4-Tec Performance
    Replies: 16
    Last Post: 05-31-2006, 05:22 PM
  3. Compression on 4-Tec Supercharged Engine
    By ramnj in forum 4-Tec Performance
    Replies: 5
    Last Post: 04-22-2006, 08:22 PM
  4. lost compression on all cylinders
    By mxl16 in forum 4-Tec Performance
    Replies: 36
    Last Post: 12-03-2005, 05:15 PM
  5. Whooops... only getting 116 compression!?
    By Phil in forum 4-Tec Performance
    Replies: 7
    Last Post: 09-04-2005, 03:55 PM

Posting Permissions

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