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Fino's Sbc Build

Discussion in 'Builds and Fabricators Forum' started by FinoCJ, Sep 25, 2020.

Page 4 of 10
  1. Oct 9, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    yes there is some pitting - more on the larger intake seat than the exhaust on #1...not sure about the rest....here it is a bit more visible after cleaning it up a bit:
    [​IMG]

    Here is the intake valve cleaned up about as much as I can do with the tools I have....good enough to work I hope?
    [​IMG] [​IMG]
     
    FinoCJ, Oct 9, 2020
    #61
    73 cj5 likes this.
  2. Oct 9, 2020
    73 cj5

    73 cj5 Not ready for the junkyard yet

    Clinton, Mississippi
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    Lap the valves and post the results. I'm curious if they will seat where the pitting is.
     
    73 cj5, Oct 9, 2020
    #62
  3. Oct 9, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
    Joined:
    Jul 18, 2013
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    like I know how to 'lap the vavles'....I spend more time googling videos than i do working on this thing
     
    FinoCJ, Oct 9, 2020
    #63
    Muzikp likes this.
  4. Oct 9, 2020
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Spokane Valley, WA
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    Consider yourself lucky. Most of us had to go look it up in the library. ;)
     
    ITLKSEZ, Oct 9, 2020
    #64
    Jw60, Ol Fogie, Snoops and 4 others like this.
  5. Oct 9, 2020
    73 cj5

    73 cj5 Not ready for the junkyard yet

    Clinton, Mississippi
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    Or you worked at a machine shop. (y)
     
    73 cj5, Oct 9, 2020
    #65
  6. Oct 9, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    Actually - I did go to the library....
    [​IMG]
     
    FinoCJ, Oct 9, 2020
    #66
    Jw60, Snoops, dozerjim and 4 others like this.
  7. Oct 9, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
    Joined:
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    I only tested the #1 valve guides, but checking the valveguide clearance by wiggling the valve with a dial indicator shows an acceptable 0.01-0.012". So...without any experience with this kind of stuff, I could use a bit more of a roadmap. So lets say I lap a valve (one for now)...then what? If it shows a good mating contact, then clean and lap all the other valves, do the valve seals and call the heads done? But, what if I cannot get a good mating surface - then what? Go ahead and use it as is knowing the valve seats are not ideal? Take it a head shop for professional work? I feel like I am getting further and further down a hole that I might not be able to get out of....Also, should I check the crank, main bearings etc on the bottom end first before doing much with the heads? Trying to (re)create my plan of steps...
     
    FinoCJ, Oct 9, 2020
    #67
  8. Oct 9, 2020
    73 cj5

    73 cj5 Not ready for the junkyard yet

    Clinton, Mississippi
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    The valves making contact with the seats is not only good for sealing purposes but also heat transfer. Valve face and seat concentricity are very important.
     
    73 cj5, Oct 9, 2020
    #68
    Fireball likes this.
  9. Oct 9, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    Agreed - to the point that I am wondering if I should take it to the machine shop....guess it can't hurt to try lapping the valves myself, but guessing that isn't going to be all that successful, and if that doesn't work, what are my options? I don't have any experience with how much pitting can be lived with on a no performance budget project, vs what is an absolute must do no matter what.
     
    FinoCJ, Oct 9, 2020
    #69
  10. Oct 9, 2020
    73 cj5

    73 cj5 Not ready for the junkyard yet

    Clinton, Mississippi
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    Assuming the heads are in need of machine work your options are to either have a machine shop do the work, you can buy the equipment and do it yourself, or you can turn a blind eye to it.

    If you fill the intake and exhaust ports with a solvent with the valves and springs in them you can see how bad the valves leak. When a customer came in and didn't want their head fixed "right" I would fill the ports with petroleum solvent and look for leaks. Once I saw which were leaking I then marked them with a paint pen and took them out. I examined the seats, valves, and guides of each one then I would touch off on the valve (with valve grinder) to see if it was in good enough shape to reface after bead blasting and continue from there.
     
    73 cj5, Oct 9, 2020
    #70
  11. Oct 10, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    That is the question I am asking...I've never seen a valve seat before today, so I have no way to judge if they need machine work. In other words, is this a little or a lot of 'damage' to the seat? I can put fluid in the chamber, and they will most likely leak some. Cold leak down tests before disassembly were not encouraging, but not sure how valid they were when cold.

    I am okay with that in some circumstances - but the judgement on when that is ok is usually based on experience and knowledge. In this situation I have neither, but basically, I have to decide whether these heads are salvageable without machine work, or whether they are unusable in current condition without work. That is what I mean about the 'roadmap' or plan...if these heads are not usable in current condition, then I have to create a whole new plan.
     
    FinoCJ, Oct 10, 2020
    #71
  12. Oct 10, 2020
    73 cj5

    73 cj5 Not ready for the junkyard yet

    Clinton, Mississippi
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    I've seen worse pitting but once you lap the valve you'll know where you stand for sure. It's an sbc. Parts are cheap and plentiful. I think you're worrying too much about this. Call a machine shop and ask for an estimate on the machine work.
     
    73 cj5, Oct 10, 2020
    #72
  13. Oct 10, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    The two shops i've called about head work want $500-600 per pair...that is WAY beyond my budget at this point.
     
    FinoCJ, Oct 10, 2020
    #73
  14. Oct 10, 2020
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
    Joined:
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    Parts may be cheap, but machine work is not....The two shops i've called about head work want $500-600 per pair...I am worried because I am a bit in over my head, and don't know what I am looking at, and I am going off the word of others without ability to verify or assess...but beggars can't be choosers and I need whatever help I can get
     
    FinoCJ, Oct 10, 2020
    #74
  15. Oct 10, 2020
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Sep 21, 2002
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    Look at a picture of a new valve, and a new valve seat....that's what they should look like. Acceptable is a matter of opinion, ask 10 people and you'll get 10 different opinions.
     
    Glenn, Oct 10, 2020
    #75
  16. Oct 10, 2020
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    I agree with 73cj5, at least try lapping one to see what you have.
     
    Glenn, Oct 10, 2020
    #76
  17. Oct 10, 2020
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Remember that any pitting whatsoever means a reduced sealing surface.
     
    Glenn, Oct 10, 2020
    #77
  18. Oct 11, 2020
    duffer

    duffer Rodent Power

    Bozeman, MT
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    duffer, Oct 11, 2020
    #78
    Norcal69 and ITLKSEZ like this.
  19. Oct 11, 2020
    73 cj5

    73 cj5 Not ready for the junkyard yet

    Clinton, Mississippi
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    I wouldn’t bolt on aftermarket cylinder heads without taking them apart and checking everything then clean them.
     
    73 cj5, Oct 11, 2020
    #79
  20. Oct 11, 2020
    duffer

    duffer Rodent Power

    Bozeman, MT
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    My experience with both Eldebrock and AFR's aluminum loaded heads has been that they far exceed any GM versions on ALL accounts, including accuracy, cleanliness, seals, springs, valves, and valve jobs. They obviously also have a multitude of options not available on the stockers. We did disassemble the AFR 1095's for the 441 bucket list engine to check how close the full CNC job was on chamber CC's. Basically perfect.

    And you get ALL new parts. In the case of the AFR's, those parts were all high end stuff including the PAC hydraulic roller springs good for 7200 rpms-something that engine will never see from my use. Those would be extreme overkill for James' project.
     
    duffer, Oct 11, 2020
    #80
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