compression numbers | FerrariChat

compression numbers

Discussion in '308/328' started by shmark, May 24, 2010.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. shmark

    shmark F1 Rookie

    Joined:
    Oct 31, 2003
    Messages:
    2,968
    Location:
    Atlanta
    Full Name:
    Mark
    I'm having a PPI performed on a euro '85 QV and just got the compression/leakdown numbers back from the shop. I think they look pretty strong, maybe slightly off on #3 but not bad at all. I am moving ahead with the rest of the PPI and with this result, I'm buying the car...barring something seriously wrong somewhere else. What do you think?

    The cold compression test results:
    1 - 180
    2 - 179
    3 - 176
    4 - 181
    5 - 187
    6 - 185
    7 - 183
    8 - 190

    Leakdown test results cold:
    1 - 7%
    2 - 9%
    3 - 11%
    4 - 7%
    5 - 6%
    6 - 5%
    7 - 9%
    8 - 5%
     
  2. Ferraripilot

    Ferraripilot F1 World Champ Owner Project Master

    Joined:
    May 10, 2006
    Messages:
    17,865
    Location:
    Atlanta
    Full Name:
    John!
    good driver numbers there. I think it's fine. new rebuilt engines with modern components are getting <1% leakdown numbers now.
     
  3. shmark

    shmark F1 Rookie

    Joined:
    Oct 31, 2003
    Messages:
    2,968
    Location:
    Atlanta
    Full Name:
    Mark
    True, but this was done dead cold on a car that has been driven just a few hundred miles in the last couple years - averaged less than 800 miles/year for the past decade. I'd expect the leakdown numbers to improve with driving, which I plan to do a lot of. And yes it will be getting a major service and probably a couple hundred miles shakedown before I pick it up.

    Now if I can just last the next few weeks.
     
  4. PV Dirk

    PV Dirk F1 Veteran

    Joined:
    Jul 26, 2009
    Messages:
    5,401
    Location:
    Ahwatukee, AZ
    I concur, buy it and drive it a lot. It will be great.
     
  5. CliffBeer

    CliffBeer Formula 3

    Joined:
    Apr 3, 2005
    Messages:
    2,198
    Location:
    Seattle, Washington
    Full Name:
    Cliff
    Those are solid numbers for a decent 308. As suggested, an "Italian tune up" would likely improve the numbers somewhat.

    Might be worth checking the valve clearances to make sure No. 3 isn't too tight....

    Is there blue smoke on start up? Leakdown won't tell you much about the condition of valve guides (but a cold start will).

    Hope all is well with the car and she treats you great!
     
  6. shmark

    shmark F1 Rookie

    Joined:
    Oct 31, 2003
    Messages:
    2,968
    Location:
    Atlanta
    Full Name:
    Mark
    Good tip on the cold start, I'll ask about it and check it myself once I get out there. It will be undergoing a major and valve adjustment will definitely be a part of that, so any clearance issues should be resolved. I'm thinking that once the service is complete, an Italian tuneup will definitely be in the cards. The only thing wrong with this car is it just hasn't been driven enough. I plan on fixing that.
     

Share This Page