New valves and valve Job -should I lap them?

Posted by blazebolt, Feb 4, 2009
Newbie Forum - Beginner DSM modification questions and discussions. Common, repetitive, and general discussions will get dumped here from other tech forums. Unless you're a Probationary member you shouldn't post threads here.

  1. blazebolt

    blazebolt Proven Member

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    Searched, but could not find a direct answer. I'm getting new Manley valves and a 3 angle valve job done on my head. Do I need to (or would I get any benifit from) lap the valves?

    Thanks
    #1
  2. JusMX141

    JusMX141 Moderator

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    The machine shop should be sure the valves seat properly before they release it to you. This would mean you do NOT need to lap the valves.
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  3. deviousgst

    deviousgst Proven Member

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    how much is the shop charging you for the rebuild
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  4. blazebolt

    blazebolt Proven Member

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    I haven't gone to the shop yet, but I will be doing most of the assembly work myself. The machine shop work I have planned are Hot Tank block and head, magnaflux block, resurface head and block, crankshaft hone, 20 over cylinder bore/hone, balance rotating assembly, pressure test head, 3 angle valve job, replace valve guides, and extrude hone (maybe).

    I'm still getting everything ready and planning what needs to be done and when. The build I'm doing is going to be pretty extensive and expensive and I will be taking my time. I will have a build log when I start the work.
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  5. Defiant

    Defiant DSM Wiseman

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    Eh, I'm from the old days. I'd lap them. It's not a tough job, it just takes time.

    Then again, I'd not bother to mag the block. I'd also save the price of an extrude hone on a turbo engine. Let the blower take care of the difference.
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  6. Colt4G63 also

    Colt4G63 also Proven Member

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    I would expect the machine shop to lap them before they put the springs and retainers on. They're doing the valve job right? I always lapped the valves when I did a valve grind. My engine instructor in college taught us that it was a standard part of the process.
    #6
  7. blazebolt

    blazebolt Proven Member

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    I originally wasn't going to mag the block, but the block has a little rust and is in unknown condition. The machine shop recommended it, with the inspection process. It sounds like a good idea for my plans with the block, so I'm going along.
    #7
  8. Defiant

    Defiant DSM Wiseman

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    glorious Galt, California
    I'm sure they don't charge that much for it, but DSM blocks aren't known for cracking. I was certified level II in Magna-Flux, and dye penetrant inspection in a life long ago.
    #8

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