Compression Test and Leakdown Numbers | FerrariChat

Compression Test and Leakdown Numbers

Discussion in '348/355' started by Parikh1234, Jul 18, 2007.

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  1. Parikh1234

    Parikh1234 F1 Rookie
    BANNED

    Apr 9, 2006
    4,726
    Little Ferry, NJ USA
    Full Name:
    Shivam Parikh
    Here is what came back today from the car I am looking to purchase:


    Here are the compression and leak down numbers:

    Comp:
    1- 221
    2-225
    3-227
    4-220
    5-223
    6-225
    7-227
    8-228

    Cyl. leak:
    1-4
    2-6
    3-4
    4-7
    5-6
    6-4
    7-6
    8-5

    The compression values are p.s.i. and the leak values are percentage.
    These are good numbers, the test was done with the engine warm. We
    consider on a 355 compression numbers in the 220 to 230 range to be good
    and 10% or less cylinder leakage to be acceptable. The engine has a
    decent idle but it could be a little smoother, the spark plugs are clean
    with no sign of oil burning. The valley for the spark plugs did have
    some 'rust' residue and some of the spark plugs have corrosion on the
    steel body above the seal indicating that some water has been in the
    valley at some time in the past. This is not uncommon on 355's, the
    gasket for the plug cover as well as the plug wire rubber seal are intact.

    What do you guys think?
     
  2. FullChat

    FullChat Formula Junior

    Jan 1, 2007
    339
    San Antonio, Texas
    Those are the kind of compression and leakdown numbers that I'm looking for.
     
  3. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    18,053
    USA
    Excellent numbers. I would have them just replace the plugs, install new cam cover gaskets and the foam seal and call it good. If the idle is still a bit lumpy it might need a new set of plug wires (not uncommon). New sets are available from www.kingsborne.com for less than $250 and they use the exact same Beru connectors and wire as the factory sets.
     
  4. Parikh1234

    Parikh1234 F1 Rookie
    BANNED

    Apr 9, 2006
    4,726
    Little Ferry, NJ USA
    Full Name:
    Shivam Parikh
    thanks alot guys. Its nice to know that the numbers came back good. I am flying down on Monday to finalize things and hang out with the tech while he does the rest of the PPI. Hopefully if there is enough time and anyone is in the texas area we can meet up for a quick dinner. I need to be back at the airport at 6 PM
     
  5. FullChat

    FullChat Formula Junior

    Jan 1, 2007
    339
    San Antonio, Texas
    Where in Texas? I'm in San Antonio.
     
  6. gothspeed

    gothspeed F1 World Champ

    May 26, 2006
    10,244
    U.S.A.
    Full Name:
    goth
    Does the idle stumble when the radiator fans come on?? I am working on a fix for this..... :)
     
  7. Parikh1234

    Parikh1234 F1 Rookie
    BANNED

    Apr 9, 2006
    4,726
    Little Ferry, NJ USA
    Full Name:
    Shivam Parikh
    dallas.

    nice. Ill let you know on monday when I see the car:)
     
  8. mrpcar

    mrpcar Formula 3

    May 27, 2007
    1,114
    Chino hills, CA
    Full Name:
    Robin
    Geez!! I wish those were the numbers on the two 355 GTB that I wanted to buy.
     
  9. bcwawright

    bcwawright F1 Veteran

    Jul 8, 2006
    5,234
    Georgia
    Full Name:
    Bruce
    Oz, what's causing this? Is there a voltage drop?
     
  10. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    18,053
    USA
    My thought as well....perhaps an alternator issue if there is a voltage drop.
     
  11. gothspeed

    gothspeed F1 World Champ

    May 26, 2006
    10,244
    U.S.A.
    Full Name:
    goth
    see below ;)

    I will publish my findings after I have the fix in the car and functioning properly ;)

    ......some pertinent componenets should be arriving today..... :)
     
  12. bcwawright

    bcwawright F1 Veteran

    Jul 8, 2006
    5,234
    Georgia
    Full Name:
    Bruce
    Thanks Oz....you're the man..lol
     
  13. Nick@Autobahn

    Nick@Autobahn Karting

    May 29, 2007
    124
    Huntington Beach, CA
    Full Name:
    Nick
    Glad to see everything is going smoothly with the PPI, Shivam!
     
  14. gothspeed

    gothspeed F1 World Champ

    May 26, 2006
    10,244
    U.S.A.
    Full Name:
    goth
    I have solved the infamous 355 idle stumbling!!!!! I will posting my full report this evening on a new thread with pics/diagrams of the solution!!! :D

    BTW should I post it in the Tech Q&A or in this 348/355 section??
     
  15. notoboy

    notoboy F1 Rookie

    Jul 8, 2003
    2,531
    NYC
    Full Name:
    David
    I would say to do it in this section, because it'd be difficult to ever find again in the general tech section. At least in here, all the stuff is about 355/348...

    IMO
     

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