Break In Break in Secrets

Discussion in '2-Stroke Engines' started by cheap ride, Apr 11, 2007.

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  1. cheap ride

    cheap ride Guest

  2. Guest

    Guest Guest

    YES! That's the good one.

    Take your time and read it all, lots of good info there.
  3. Hugemoth

    Hugemoth Guest

    Many years ago Vespa did a scientific study to determine the best way to break in their 2 cycle engines. The study was conducted on their 50cc moped engines which are rotary valve, cast iron cylinder, bronze wrist pin bushing. Some were driven slow and easy, some were driven at a steady moderate speed, some were driven wide open. The conclusion was that it didn't make any difference.

    The Chinese engines are somewhat different in that they use a chrome bore and soft rings.

  4. Guest

    Guest Guest

  5. Hugemoth

    Hugemoth Guest

    The only thing that would concern me about running the hell out of a new engine would be the wrist pin bushing. I've seen a couple of them spin in the rod, causing the oil hole to get out of line with the oil hole in the top of the rod. That may not be a big deal.

  6. Guest

    Guest Guest

    Yes, but wouldn't you agree that if the bushing was going to move, it's going to move regardless of how much time or stress is put on the engine?
  7. Hugemoth

    Hugemoth Guest

    I think the bushing is more likely to move when it is new and tight on the wrist pin.

  8. Guest

    Guest Guest

    Possible, but it really shouldn't be moving, ever.
  9. Guest

    Guest Guest

    Also, this notion of breaking in an engine "like you stole it" or "like you are racing it" is a bit of a misconception.

    The idea is not to beat on the engine, but to run it at various on/off throttle loads, with plenty of wide open throttle (which is different from high RPM running, which is different still from running hard up against the redline.)

    The use of this type of break in allows the rings to seat and to use the engine as it was designed, not beyond it's limits.
  10. wzuccarello

    wzuccarello New Member

    i learned a LOT here, enjoy

  11. GearNut

    GearNut Active Member

    That is an excellent article. I have been breaking in engines this way for years. It is also the way my mentor (RIP) had taught me. It really does make a difference in overall power output and upon future teardown of the engine you can tell a big difference concerning residue buildup on the piston skirts. (The brown stuff most pistons get on the skirts is greatly reduced)
  12. Skyliner70cc

    Skyliner70cc Active Member

    I break all of my engines this way to include my personal vehicles. A couple of years ago,I compared cylinder compression between my vehicle and a friend's vehicle-we both owned the same vehicle. We had roughly the same mileage (about 48k miles) and I was running about 40psi more cylinder compression. I was pushing about 520psi and he was 480psi average across 4 cylinders. He drove his vehicle gently since it was new and was burning about 1 liter of oil between oil changes (10,000 mile oil chang interval). I burned about 1/4 liter for the same oil change interval using the same oil. When the vehicle got more miles on it, I eventually was pushing close to 550 psi and my friend's TDI never got over 500 psi. I drive all of my vehicle's hard when new, vary the load on engine, vary engine rpm, and NEVER use constant speed or load engine settings for the first 10k miles.
  13. give me vtec

    give me vtec Active Member

    Sorry guys... Hate to break it to you but, the first couple of people that test drove your car before you probably had more to do with your break in than you did. Most of the break in occurs within the first 50 miles... And is completely done within 500-1000.
  14. Skyliner70cc

    Skyliner70cc Active Member

    Sorry Vtec, not true in all cases. On my vehicles (all diesels), it took approximately 50k miles for the rings to be fully seated as evidenced by compression values and oil consumption. Once compression peaked in the mid 500 psi values, it held there for over 200k miles then slowly began dropping.
  15. give me vtec

    give me vtec Active Member

    Lol, Never owned a diesel... Would you be more comfortable if I narrowed the scope of my comment to gasoline engines????
  16. Skyliner70cc

    Skyliner70cc Active Member

    No, there always seem to be exceptions to the normal rules. I still believe it takes 10k miles for a gas engine to break in but don't have the hard data such as compression values and can only go by oil consumption. Yes, early starts and early use are very important as you say. If you glaze the rings with light usage and not warming up engine and varying load/rpms when an engine is brand new, you are SOL. In the old days, if this happened, a little Bon Ami into the intake would fix this but don't do this on a new engine. This trick was used on older engines with slower piston speeds and I found that it was actually a GM approved method to seat rings/break in engine on their 1955 V8s.

    The power and fuel economy increases with a diesel are very noticeable once theyare broken in. As for small engines, it depends on the use of the product on how long it takes to break in. Most of my HT engines are dogs until they get about 7-10 hours of use on them and then they just wake up one day and have tons of power and are easier to start. It took my 3.5kw generator about a week's worth of continus use while camping before it would hold a load above 3k watts without bogging down.

    On my 06 VW TDI, I started out at 39mpg and when hit 50k 47mpg was the norm on summer fuel. The mileage differences with a gasser are not as noticeable probably because of the magnitude of new versus broken in compression values.
    Last edited: Dec 26, 2010
  17. give me vtec

    give me vtec Active Member

    Yeah you're probably right... I'm sure the first few hundred thousand times an engine turns over has little to do with the break in. It's the ones that come after those that count... Right?
  18. give me vtec

    give me vtec Active Member

    Here's my break in... Use regular Dino oil for the first 12k. Vary the throttle only using 3/4 of the rpm range. I usually Drive city for the first couple hundred miles... Then I drive to the beach varying the throttle and rpm the way there. On the way back about half way home I redline it a couple times, holding it a little longer every time. When
    I get home I basically consider it broken in. I generally take it easy for the next 5k or so just to let everything else on the car settle in.

    Change the tranny/diff fluid using oem fluids, and engine oil using mobil 1... at 12k. Change the oil every 2500 miles.

    None of the engines i bought new burn oil.

    In all reality though... On a new car it really doesn't make a noticeable difference to the average person. Unless you absolutely abuse your engine right out of the box and never service it... Your engine is most likely going to be just fine regardless of what you do.
    Last edited: Dec 26, 2010
  19. Stan4d

    Stan4d New Member

    To conserve space and keep info in one place I merged the thread.
  20. Dave C

    Dave C Member

    You change an oil made to run for 15,000 miles every 2500 miles? That's 6 times as often as recommended. I ran Mobil 1 in my taxi's, never had an engine failure tied to oil(dumb****s running them after a water pump gives out another story :p ).