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F head variation - color code?

Discussion in 'Early CJ5 and CJ6 Tech' started by kamel, Nov 23, 2004.

  1. kamel

    kamel Senior Curmudgeon

    If I recall correctly the F head engine came from the factory in different colors and these colors meant something.

    I think that the high altitude engines with different compression ratios were different colors.

    I have a yellow one - everthing is yellow - block, head, valve cover. Does that mean anything, or just that it was painted yellow.
     
    kamel, Nov 23, 2004
    #1
  2. Fhead Guy

    Fhead Guy Member

    As far as I know all the Fhead engines were originally painted black. I don't recall reading anything in the willys books about the high altitude engines being painted a different color. I'm sure someone from a "high altitude" location like CO can weigh in on this one-

    John
     
    Fhead Guy, Nov 23, 2004
    #2
  3. Glenn

    Glenn Kinda grumpy old man Staff Member

    Here's some info regarding F-head color codes. This is from a reprinted Master Parts List for the wagons and trucks, so I don't know if it applies to CJs. It is for complete engines and lists them as follows:

    painted black, 7.4 to 1 compression, and the description is low altitude domestic, high altitude export.

    painted yellow, 7.8 to 1 compression, high altitude domestic

    painted blue, 6.9 to 1 compression, low altitude export
     
    Glenn, Nov 23, 2004
    #3
  4. blevisay

    blevisay Oh Noooooooooooooooo! Staff Member

    I though the blue head was the high compression one...........
     
    blevisay, Nov 24, 2004
    #4
  5. kamel

    kamel Senior Curmudgeon

    I thought that blue was high altitude as well. However, I can trace this yellow engine from Colorado, so maybe yellow is high altitude.
     
    kamel, Nov 24, 2004
    #5
  6. aklimko

    aklimko New Member

    Huh,

    Didn't know that. But that would explain why mine doesn't run so good when I take it for a ride up in the mountians in PA. But runs like a champ everywhere else.
     
    aklimko, Nov 24, 2004
    #6
  7. aklimko

    aklimko New Member

    BTW it is painted blue
     
    aklimko, Nov 24, 2004
    #7
  8. Fhead Guy

    Fhead Guy Member

    Wow . . . you learn something new every day. I've seen a couple of engines painted blue, and assumed they were rebuilds. Never seen a yellow engine.

    I never understood from reading the books that the parts between the three engines supposedly interchange, and that the torque and HP specs remained the same . . . didn't seem logical, but then I'm not an engine guy.

    Out of curiousity, what is the difference in altitude between your home and where you are driving in the mountains?

    Eck
     
    Fhead Guy, Nov 24, 2004
    #8
  9. aklimko

    aklimko New Member

    There is a huge difference.
    Home is at 291 m 954 feet
    Hunting spot 1 is at 716 m 2350 feet
    Hunting spot 2 is at 976 m 3213 feet (this is at mount davis the highest point in PA)
     
    aklimko, Nov 24, 2004
    #9
  10. Hawk62cj5

    Hawk62cj5 Captain of OldSchool

    Mine is chevy orange lol . When I cleaned mine up the engine had a few spots of black over it and the head was a light blue in color. So does that meen that I have a reg alt eng with a low compression head ,,,if so :cry: ...... mr machine shop man can you shave this down for me ;)
     
    Hawk62cj5, Nov 24, 2004
    #10
  11. blevisay

    blevisay Oh Noooooooooooooooo! Staff Member

    It was only the head that was painted.......IIRC........
     
    blevisay, Nov 24, 2004
    #11
  12. Glenn

    Glenn Kinda grumpy old man Staff Member

    I interpreted the manual as saying the whole engine was painted the appropriate color. It lists different part numbers for the engines with the different compression, and just says painted and says the color.
     
    Glenn, Nov 24, 2004
    #12
  13. kamel

    kamel Senior Curmudgeon

    Is there anywhere where the casting numbers are described? The casting number on my yellow engine begins with SD, and is different from most of the other f head engines I have in the shop.
     
    kamel, Nov 24, 2004
    #13
  14. Glenn

    Glenn Kinda grumpy old man Staff Member

    I haven't seen anything about casting in the parts manual. I noticed the engine colors listed by accident. I was comparing parts numbers with some stuff listed on e-bay and noticed the engine descriptions. I would imagine a CJ parts manual would list the same type of info, but I don't have one to check. :(
     
    Glenn, Nov 24, 2004
    #14
  15. kamel

    kamel Senior Curmudgeon

    The CJ parts manual lists the different heads and mentions the special high alt carb, but does not name colors.
     
    kamel, Nov 25, 2004
    #15
  16. Glenn

    Glenn Kinda grumpy old man Staff Member

    Does the CJ parts manual list whole engine assemblies with specific parts numbers?
     
    Glenn, Nov 25, 2004
    #16