1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Motor Oil for break in

Discussion in 'Engine Building' started by word, Sep 18, 2004.

  1. word

    word Senior Member

    Messages:
    365
    Likes Received:
    0
    Joined:
    Feb 10, 2003
    Why do people always say use non synthetic non detergent oil for break in? The rings and bearings are broken in after 20 minutes of driving......why not use synthetic oil if it lubricates better?

    someone please give me an explanation. i'm thinking about using castrol syntec 5-30W for my newly rebuilt motor (12:9 compression)

    thanks
    chris
     
  2. StyleTEG

    StyleTEG Senior Member

    Messages:
    217
    Likes Received:
    0
    Joined:
    Oct 22, 2003


    The rings and bearings are not broken in after 20minutes of driving, and even if they were that 20minutes with a synthetic would make it harder for the rings and bearings to break in properly.

    You are only supposed to use a non detergent oil if your engine was rebuilt in a clean room. Otherwise just use a regular nonsynthetic oil.
     
  3. YouKnowWhoIBee

    YouKnowWhoIBee my avatar is better.

    Messages:
    2,257
    Likes Received:
    7
    Joined:
    Dec 22, 2003
    Location:
    Maryland
    Use mobil 1 it is worth it .
     
  4. h82w8

    h82w8 Senior Member

    Messages:
    334
    Likes Received:
    0
    Joined:
    Dec 18, 2002
    Location:
    orlando,florida
    the reason you dont use synthetic on a rebuilt motor for break in is because the rings and cylinder wall must have some sort of wear pattern, the synthetic oil doesn't let the rings score properly. just use regular oil whatever viscosity you plan to use change it at 500 miles and 3000 miles and switch to synthetic if you want ;)
     
  5. h82w8

    h82w8 Senior Member

    Messages:
    334
    Likes Received:
    0
    Joined:
    Dec 18, 2002
    Location:
    orlando,florida

    :surprise: :eek3: :eek3: :eek2: :eek:
    ...seems like something I would test on a chainsaw or something first!
     
  6. word

    word Senior Member

    Messages:
    365
    Likes Received:
    0
    Joined:
    Feb 10, 2003
    i've read that site, but my engine is NOT tuned yet and I'd hate to have any pinging on a new block. I'll be using 93 octane gas and some octane adder from autozone, retard the timing and crank up the fuel pressure to keep the detonation to a minimum.


    I guess I'll use Mobil 1 5-30W non synthetic, the motor was assembled in a garage.

    thanks a lot!

    chris


     
  7. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

    Messages:
    28,465
    Likes Received:
    228
    Joined:
    Sep 30, 2002
    Location:
    Dallas / Fort Worth, TX


    :thumbsup:
     
  8. NoJokE

    NoJokE Senior Member

    Messages:
    1,317
    Likes Received:
    0
    Joined:
    Jan 6, 2003



    That would be the stupid thing to do, when starting a fresh engine, you should have stock fuel pressure of 42 psi, stock timing of 16 degrees BTDC, and i dont recommend using octane boost.

    I just started my motor last week and have put 350 miles on it so far with the slow break in, and did a compression test and i got 180 psi across the board. Im running low comp pistons thats why it seems relatively low.
     
  9. word

    word Senior Member

    Messages:
    365
    Likes Received:
    0
    Joined:
    Feb 10, 2003
    i'm not sure how the engine will idle, i'll have a 255lph fuel pump, FRP, 310cc injectors, and a stock p28.

    I guess under closed loop it'll be okay because the ecu will adjust the fuel curve by the o2 sensor readings.....but anything higher than 25% will send the ecu into open loop and i'm pretty sure the fuel map is not sufficient for the new motor.
     
  10. NotUrAverage_Si

    NotUrAverage_Si Senior Member

    Messages:
    2,255
    Likes Received:
    0
    Joined:
    Jul 9, 2003
    Location:
    :/
    OT, but I just spent almost $50 on Royal Purple synthetic motor oil. :eek:
     
  11. MikeBergy

    MikeBergy Blah blah blah....

    Messages:
    3,646
    Likes Received:
    1
    Joined:
    Oct 9, 2003
    Location:
    Central Coast, CALI
    I'd change the oil a bit sooner than 500 miles. Get one of those magnetic oil pan plugs too, It will keep the ring and wall material that wears down from cycling through the engine and clogging the filter. Using synthetic oil is not going to keep your motor from pinging, if it IS going to ping, it will regardless of what motor oil you use. 12.9 is kind of high, maybe you should just invest in a couple gallons of race gas to break it in with, that way you can run stock timing and fuel maps and have no worries.
     
Verification:
Draft saved Draft deleted

Share This Page