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225 Rebuild- What To Do?

Discussion in 'Early CJ5 and CJ6 Tech' started by Chuckman, Aug 17, 2018.

  1. Aug 17, 2018
    Chuckman

    Chuckman New Member

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    Got a '69 225 purchased disassembled. Bores/journals look amazing and stock sizes. So Im not going to do anything but have it honed and polished. The heads though, what to look for there? New springs? New hardened seats? New valves? Since block was disassembled I cant match the lifters with the bore- so thats an issue. I have not measured the lobe heights on the cam but the journals are dead on and gorgeous. Not afraid to spend money on a build but for the life of me I cant imagine why they took this thing apart. Its as nice as they come inside.
     
  2. Aug 17, 2018
    tarry99

    tarry99 Member

    Northern California
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    Measure everything.......with a micrometer.......and the bores with a dial bore gauge.....Heads? a valve job at the minimum........hardened seats yes........check the flatness on the head surface........the rockers should also be checked.........lifters & cam shaft , timing chain , oil pump and cover.............things that look good via your eyes may not be so when measured.............................since it's apart make sure everything goes back together correctly...........

    This may help!..................Blueprint 225
     
  3. Aug 17, 2018
    Daryl

    Daryl Sponsor

    Bonney Lake, WA
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    Many Buick v6 motors have been taken apart to rebuild for "low oil pressure" when someone doesn't know that most of these motors had very little oil pressure when they were new.
     
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  4. Aug 18, 2018
    Chuckman

    Chuckman New Member

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    edit : should have mentioned more clearly that everything not only looks good but measures to spec. including cylinders/crank/cam and block
     
  5. Aug 18, 2018
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    USA
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    As Tarry Stated, make sure its all right...

    OTOH, I "rebuilt" my 225 once where i put in everything new.. Then when I sucked in 2 nuts and a washer and destroyed 3 pistons and a couple valves, I fixed it with a 3 stone hone, lapped some old valves and junk parts. Runs better than before now:lol:

    Sometimes making it run is all that matters since you're not driving it out into the middle of the sahara or entering the baja 1000 with it. Put in new rings, bearings, a cam and lifters and run it

    I get 20psi hot idle oil pressure with mine. All the 225's I have taken apart have significant valve train problems. Fix them and you're good to go.

    I need some engine advice
     
  6. Aug 18, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    I'd have the block cleaned and checked for cracks (magnaflux). Get some rifle brushes and clean the oil galleries. What's your skill level? This book is an excellent introduction to engine building Engine Builder's Handbook: Tom Monroe: 0075478012459: Amazon.com: Books The 225 is a conventional V-engine typical of the era, except for the odd-fire aspect. The odd-fire thing does not affect building the engine at all, AFAIK.

    Are the heads assembled? The investment needed to rework heads yourself does not make sense for 99.9% of owners. You are pretty much at the mercy of your shop regarding what your heads need. Typical head job includes disassemble, clean, magnaflux (check for cracks), inspect, 3-angle grind, assemble and paint. Every reputable shop will have a price sheet showing the charge for every operation. Often exhaust valves need replacing. You can expect the shop will recommend some type of guide reconditioning. The least expensive is knurling, and IMO that's fine for most of these Jeeps that are hobby cars and won't see a lot of miles. Likely the shop will also recommend to surface, though V6 heads are short and probably won't need it. If you measure with a precise straight edge before sending in, you can confidently decline that operation. Tarry recommends hardened seats - I would question whether you really need that, and only the exhaust seats take a beating. Maybe he can elaborate a bit on that point.

    New lifters on an old cam is allowed. If you have old lifters and an old cam and they are mixed up, you'll have to discard the lifters and buy new ones.

    Did you measure bore taper? Have it been bored oversize, and new pistons fitted? You can put new rings in a crooked bore, but lifetime will be shortened due to fatigue from the extra expansion/contraction of the rings with travel. You need a crosshatch finish for new rings, and only cast iron rings are allowed for replacement in crooked bores - no moly or chrome - they may not seat.
     
  7. Aug 18, 2018
    Chuckman

    Chuckman New Member

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    fully rebuilt my GPW 4cyl to mint- but it was shot to pieces and needed all kinds of love. Just shocked to see this all good and clean. You can throw good money after bad and you can guild the lily too, trying to find a nice balance based on folks' experience.

    I was expecting 'oh, well on those things, you MUST do blah blah blah'


    get this, the GPW was literally 'shot'; it had two big bullet holes below the pushrod gallery and I took another dead motor, cored out two big 4" round chunks, had them stitch welded in to original motor and then align bored. BUT when you find a numbers matching GPW, you do such things.
     
  8. Aug 18, 2018
    tarry99

    tarry99 Member

    Northern California
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    Unleaded fuel Vs Leaded...............New motors all have hardened seats.....and are also complemented by having smart fuel & ignition management systems that allow them not to beat themselves up......

    Early motors were built with less than complementary materials as we know of today and needed the lead in the fuel to help against pre-ignition , detonation and damage to valve seats........If you think back many years ago when your father took his car to the garage.........90% of the time it had a burnt valve & needed a valve job and for the most part only on the exhaust side........Why? Cause the seats were beat out of the heads..........Today If your dealing with un-leaded fuel , an old motor and you want to fix it right and not mess with it again for a long while..........I personally would put hardened seats on the exhaust side.
     
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