Valve lash adjustment

Discussion in 'Subaru' started by don january, Feb 28, 2019.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Feb 28, 2019 #1

    don january

    don january

    don january

    Well-Known Member

    Joined:
    Feb 11, 2015
    Messages:
    2,642
    Likes Received:
    1,069
    Location:
    Midwest
    I have a question for those who may know the answer. Can a person set the valve lash on a 2.5 subaru while the heads are off the block? Or is it best to do once engine is assembled ?
     
  2. Feb 28, 2019 #2

    Angusnofangus

    Angusnofangus

    Angusnofangus

    Well-Known Member

    Joined:
    Sep 29, 2015
    Messages:
    329
    Likes Received:
    143
    Location:
    Victoria, Canada
    I don't know specifically about the Subaru, but I believe valves should be adjusted hot.
     
    don january likes this.
  3. Feb 28, 2019 #3

    N8053H

    N8053H

    N8053H

    Well-Known Member

    Joined:
    Jan 31, 2013
    Messages:
    2,521
    Likes Received:
    441
    Location:
    Right here in front of my computer
    On a vw you set the valves when the engine is cold.
     
    don january likes this.
  4. Feb 28, 2019 #4

    don january

    don january

    don january

    Well-Known Member

    Joined:
    Feb 11, 2015
    Messages:
    2,642
    Likes Received:
    1,069
    Location:
    Midwest
    Thank you guys for input but I have the Subaru heads off and would like to set the lash while on the bench. I can not see in my mind why I couldn't set the lash but I have not been able to find any info regarding it being done with heads off. Pops do you have an idea? I imagine it would be no different then doing a VW head sitting on the bench
     
  5. Feb 28, 2019 #5

    Toobuilder

    Toobuilder

    Toobuilder

    Well-Known Member

    Joined:
    Jan 20, 2010
    Messages:
    4,447
    Likes Received:
    3,246
    Location:
    Mojave, Ca
    Is this a pushrod engine like a VW? If so, then there will be no lash until you have the cam, lifter, pushrod, rocker, valve relationship established.
     
    don january likes this.
  6. Feb 28, 2019 #6

    don january

    don january

    don january

    Well-Known Member

    Joined:
    Feb 11, 2015
    Messages:
    2,642
    Likes Received:
    1,069
    Location:
    Midwest
    There is no push rods on the 2.5 Subaru engine. The heads have a single over head cam and that's the main reason I have no idea if valve adjustment can be set accurately off the block. I just don't see why not and thought possibly some one has crossed this road before. x head 1.jpg x head 2.jpg
     
  7. Feb 28, 2019 #7

    Hot Wings

    Hot Wings

    Hot Wings

    Well-Known Member HBA Supporter

    Joined:
    Nov 14, 2009
    Messages:
    6,389
    Likes Received:
    2,311
    Location:
    Rocky Mountains
    Kind of depends on which Subaru version you are working on. Normal in the car valve adjustment is done cold and should make little difference if the head is attached to the bloc or is on the bench. If you have a bucket lifter version the only practical way is to do the adjustment on the bench. I'm not well enough versed on all of the Subaru variations, but if there is a bucket valve version with hydraulic lifters than there will be an additional bit of procedure to follow.

    IMHO the non-hydraulic Subaru bucket valves are not such a great idea. The last time I worked on an OHC with non field adjustable lash was an old Aston Martin. My brother is on his third set of Subaru heads due to burned valves. In fairness it's not all the designs fault. He needs to find a better mechanic.

    Edit: just saw the pics. Do it on the bench.
     
    don january likes this.
  8. Feb 28, 2019 #8

    don january

    don january

    don january

    Well-Known Member

    Joined:
    Feb 11, 2015
    Messages:
    2,642
    Likes Received:
    1,069
    Location:
    Midwest
    Thank you Hot Wings. I thought as long as the cam lobe was not forcing the spring down and opening valve valve lash could be set more precise and much easier on the bench. Thanks again to all. Don
     
  9. Mar 1, 2019 #9

    TFF

    TFF

    TFF

    Well-Known Member

    Joined:
    Apr 28, 2010
    Messages:
    11,643
    Likes Received:
    3,272
    Location:
    Memphis, TN
    Yes you can.
     
    don january likes this.

Share This Page



arrow_white