Volvo RWD 200 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 9/2005 200 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

What should the compression on a B21ft be? 200

posted by  Jessie on  Sun Apr 17 01:33 CST 2005
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Tue Jan 18 17:45 CST 2011
[RELATED]

All the Bently gives is a minimum, and its the same for all of the engines. Shouldn't the b21ft have lower compression, since it has a lower compression ratio than the NA blocks?.
I am reading 130 on cylinders 2, 3 and 4, and 125 on 1. I know #1 has a problem, but is 130 about normal for a B21ft?








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    What should the compression on a B21ft be? 200

    posted by  smith_t240 on  Sun Apr 17 17:47 CST 2005
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Tue Apr 24 02:21 CST 2007
    [RELATED]

    I've been wondering this for a real long time, finally someone got some answers.

    My 1983 244T has 130 on all 4, and exactly 130 at 217k miles.

    My 1984 244Ti has 130 on the first 3, 135 on 4, at 168k miles.

    130 psi seems pretty common huh?? I figure there's got to be a formula to figure it out.

    Smith








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    What should the compression on a B21ft be? 200

    posted by  someone claiming to be Charles on  Sun Apr 17 12:18 CST 2005 [RELATED]

    I don't have the information in front of me so I could definitely be mistaken, but I believe that the Volvo Green Book cites 120 psi as a minimum value and 160 psi as maximum. The difference between your #1 cylinder and 2,3,4 is negligible. Again, I don't have the book here to reference, but I believe that a deviation between cylinders of as much as 10% is acceptable.

    For an engine with almost 250K miles, 130-ish sounds healthy. Personally have an '85 244Ti with the same engine and at 231,7xx miles I am also testing between 130 to 140 psi. This is an original motor - have never even taken the head off.

    Do you have any running problems?








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      What should the compression on a B21ft be? 200

      posted by  Jessie on  Sun Apr 17 13:41 CST 2005
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Tue Jan 18 17:45 CST 2011
      [RELATED]

      Yes thanks, I just wanted to know what the compression was on a B21ft in good condition. Yes the engine has many problems, but it runs ok. It has numerous oil leaks, and a tick (probably the exaust manifold gasket), and the OD seals are gone.
      I have a second rusted out turbo I picked up for 25 bucks that appears to have a better engine/gearbox/turbocharger, so I am trying to decide if it is worth swapping the whole thing instead of trying to patch up whats in it. Its a lot easier to replace seals and clean up the engine when it is sitting on the floor. Hopefully the engine in the rusted out one will have a little better compression.








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    What should the compression on a B21ft be? 200

    posted by  someone claiming to be Joe S. on  Sun Apr 17 12:03 CST 2005 [RELATED]

    Hello,

    130 psi is fine. I would not be at all concerned with the 5 psi difference between cylinders. This is definitely within tolerance. I measured my B21FT several years ago, and I believe that mine was around 130 to 145 (my car has been very well maintained, also). Anyway, yours sounds just fine.

    Joe S. - Volvo Master Technician

    1988 760 Turbo w/273k miles, 1981 242 Turbo w/243k miles.








  •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

    What should the compression on a B21ft be? 200

    posted by  Jerry Warren on  Sun Apr 17 03:07 CST 2005
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Tue Sep 2 17:06 CST 2008
    [RELATED]

    Compression Ratio is listed at 7.5 With only 5 psi difference between cylinders, I wouldn't be concerned. The turbos have dished pistons to reduce the compression ratio. I never measured the compression on my turbos but the value would be higher than yours as these are B230FTs.







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.