Results 1 to 8 of 8

Thread: 308 health

  1. #1
    casual poster
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    349

    Default 308 health

    Hi everyone just wondering if you can watch the attached video. I use to vent my motor to atmosphere but have now plumbed to pcv. Wondering if anyone thinks its missing at all and can check the smoke it seems its intermittent or perhaps one offending cylinder. I do notice with my ir heat gun cylinder number one header temp is way down below 100 degrees always this cylinder always has the highest psi compression and when i pull the spark plug the threads are oil soaked. Idle is about 900rpm when warm this was filmed with auto choke on so about 1200rpm. I moved piston one to tdc i can see the black coated filth on it whats a good way to remove carbon buildup without pulling the heads ive heard about the water down the carb method but a bit sceptical on quantity etc.


    Sent from my SM-G900I using Tapatalk
    Last edited by bfhoon; 15-04-2018 at 09:06 PM.

  2. #2
    casual poster
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    349

    Default

    youtube video removed
    Last edited by bfhoon; 17-04-2018 at 05:51 PM. Reason: mistake

  3. #3
    Do you ever leave?
    Join Date
    Jul 2009
    Location
    SA - Sthn Adelaide Foothills
    Posts
    2,912

    Default

    We cant tell much about the engine from a vid - just looks like an idling engine.

    You may have worn rings or worn valve seals, low comp causing inefficient burn - all these are a $$$ fix IF indeed they are a prob.

    HOWEVER, one thing that we can tell looking at the vid is that the engine is not about to spontaneously burst into flames or implode.

    Just step back for a moment mate; you are looking at cleaning dirty pistons . . . Don't overthink it! Don't go looking to fix problems that may not be there. Drive your car and enjoy it; it is not going to explode.

    If you want more, save your $ and have your engine rebuilt or build another. Then you will know your engine is fresh, you will know what you have and what performance to expect.

    Disclaimer though; I know peeps that have spent coin on a new engine, more coin than they could afford, and they lost the passion. With the benefit of hind sight they look back and say 'I should have kept the old engine - there was absolutely noting wrong with it, it ran fine.'

  4. #4
    Senior Member
    Join Date
    Jan 2017
    Location
    Nth Qld
    Posts
    573

    Default

    HI
    Smoke on start up is guide seals/orings

    Anyways compression can still be good and get a little oil usage .
    This just means the 2nd and oil ring are getting tired

    Dry and Wet Compression test all cylinders within 10%

    Leakdown test all cylinders under 5 % great 5-10 % borderline Over 10% needs repair
    Race engines are real strict on this over 5% rebuild time . Some builder aim for less than 3% leakage

    Ignition inspection required

  5. #5
    Senior Member VHSLX253's Avatar
    Join Date
    Jul 2004
    Location
    Adelaide Hills, Adelaide
    Posts
    590

    Default

    Dry and wet compression test and leak down test, what do these test tell specifically about the engine ?

    Cheers,

  6. #6
    Do you ever leave? HQ308Ute's Avatar
    Join Date
    Dec 2011
    Location
    Adelaide
    Posts
    2,460

    Default

    crap all over piston crowns is bad valve guides.. i'm with Bill on just driving it till you can do a complete job on the motor.. dont throw dollars at it that dont really achieve anything.

  7. #7
    Senior Member
    Join Date
    Jan 2017
    Location
    Nth Qld
    Posts
    573

    Default

    Hi

    Dry compression test tells u a base line

    CRANKING MUST BE THE SAME EXACTLY FOR ALL CYLINDERS , TYPICALLY 8--10 CRANKS
    sometimes the throttle has to be opened 100% --same amount every cylinder

    10 % variation problem ??????????

    WET TEST
    Same as above
    but with 3 or 4 squirts of oil out of a oil can . Same in each cylinder . DO 1 at a time
    EACH CYLINDER MUST BE TESTED THE SAME WAY
    If the compression comes up it seals the rings ,if it does not u have a leaking valve or a valve kept open by clearances being up the spout eg solid cam =valve riding

    The leak down tester
    Cylinder on compression stroke TDC [top dead centre ] prefer warm engine
    set shop air regulator to 100psi
    feed the shop air to leakdown gauge ,,zero gauge adjust
    connect to each cylinder
    the reading will show a number of leak down ==air escaping
    listen out the inlet /exhaust/ oil filler =crankcase for rushing air

    balance test
    connect accurate digi tacho pull each ignition lead
    The Rpm / cylinder that drops the least is your problem
    do tests above

  8. #8
    casual poster
    Join Date
    Feb 2012
    Location
    Australia
    Posts
    349

    Default

    Quote Originally Posted by swampy View Post
    Hi

    Dry compression test tells u a base line

    CRANKING MUST BE THE SAME EXACTLY FOR ALL CYLINDERS , TYPICALLY 8--10 CRANKS
    sometimes the throttle has to be opened 100% --same amount every cylinder

    10 % variation problem ??????????

    WET TEST
    Same as above
    but with 3 or 4 squirts of oil out of a oil can . Same in each cylinder . DO 1 at a time
    EACH CYLINDER MUST BE TESTED THE SAME WAY
    If the compression comes up it seals the rings ,if it does not u have a leaking valve or a valve kept open by clearances being up the spout eg solid cam =valve riding

    The leak down tester
    Cylinder on compression stroke TDC [top dead centre ] prefer warm engine
    set shop air regulator to 100psi
    feed the shop air to leakdown gauge ,,zero gauge adjust
    connect to each cylinder
    the reading will show a number of leak down ==air escaping
    listen out the inlet /exhaust/ oil filler =crankcase for rushing air

    balance test
    connect accurate digi tacho pull each ignition lead
    The Rpm / cylinder that drops the least is your problem
    do tests above

    Since I dont know my cam specs would a solid cam be likely for an ex 308 turbo setup? Or more interestingly what would be a good choice of cam for a 308 turbo blow through setup so I have some idea on what it may have? Just after opinions really as a learning curve probably will be rebuilding this motor soon.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Chopper Read's Health Retreat
    By chopperread57 in forum Comedy Central
    Replies: 3
    Last Post: 15-07-2007, 01:15 PM
  2. Your Health. Q&A time!
    By lil in forum Comedy Central
    Replies: 1
    Last Post: 10-01-2006, 02:16 PM
  3. health warning.
    By kiwi in forum Comedy Central
    Replies: 12
    Last Post: 16-08-2005, 08:39 PM
  4. Government Health Warning
    By Rat454 in forum Comedy Central
    Replies: 1
    Last Post: 13-09-2004, 11:42 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
  •