1988 DAX for sale in Mi.

Discussion in 'FOR SALE on Craigslist' started by Boomer3, Apr 26, 2013.

  1. kirrbby

    kirrbby Well-Known Member

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    Well alot of the odd stuff that Terry did is explained now I spose. I always said he was the mad scientist of engine builders...and this engine is another good example of that. He made it work with what he had. I sure wish he would have had the correct pinion gear tho.

    I feel like I'm getting better at this shit my damned self too.

    I didn't put the cam chain in until I was ready to mount the head...recommended.
    I used my strap wrench on the flywheel to hold the crank at TDC while I installed the piston and cylinder...recommended.
    I made a makeshift ring compressor out of a quality water bottle and spring clamp...recommended.
    I learned to install the wavy oil ring first...then the thin steel oil rings...recommended.
    I learned to install the rings on the piston at the kitchen table while wifey is at work, then hold them in position, correctly gapped, and compressed into the grooves with the spring compressor, until the piston is installed into the cylinder...highly recommended.
    I learned to wait until the wrist pin is installed, with both clips in place before I oil it all up...recommended.


    I would like to be able to just put this engine back together, run it for a minute and then send the bike back to my son.
    But...I'm a little scared to do that. I DID watch the oil temps during break-in...diligently, when I was breaking it in. It only would run hot during long runs at WOT. But, it WOULD run hot. I worry if he will be as diligent as I was. Then there is the discolored wrist pin. I'm thinkin I have to add a cooler before I send it home with him...for good measure, and a job well done, and all of that. I worry it'll be a pain in the butt, AND ugly when it's done.

    It don't look like the doc got my parts shipped today.
     
  2. kirrbby

    kirrbby Well-Known Member

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    Still waiting on parts.
    The head gasket from MW is just a single layer of stamped...metal. the metal ones that I've bought from DrATV are triple layer...
    I'm apprehensive about using the super thin lookin gasket between the cylinder and head. I could use the copper spray on it??
    Or I could use some Yamabond?? As I see recommended here on spanglers site...
    ____________________________________________
    • Lightweight aluminum cylinder with steel sleeve 57mm high compression piston w/13mm wrist pin. For engines with big valve cylinder heads(27/23mm or 30/23mm) and 57mm stroke.
    • No case machining needed
    $179.00

    • Installation notes: Its very important that you use Honda bond (or similar quality) sealer on the head gasket. Also, don't use the original o-rings between the head and cylinder (not needed) but do re-use the large o-ring at the bottom of the cylinder between the cylinder and the engine case at the oil return.
    57mm Replacement Piston Kit

    • Includes Piston, Rings, Wrist pin and Gasket
    ____________________________________________


    Or I could use it as is??
    Or I could use the one that I have in there from a TB top end gasket kit??


    I have the clay, and I'm game to clay the new setup when I start back in on it. I don't want to put the work into claying the old setup tho.

    BTW...I have more clay than I could use in 5 lifetimes. If anyone wants some, I could ship you a chunk or 2 for cheap.
     
  3. racerx

    racerx Administrator
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    The head gasket in your black bike is a steel shim type. It's OEM Honda. The stamping details provide more than enough crush to seal everything. Both gasket types (composite & stamped shim type) have their own properties as well as their own strengths & weaknesses. A thick, composite, gasket can obviously take up a lot more unevenness. It also results in more deflection/warping of the head casting and top of the cylinder. A shim-type gasket has to rely on its stamped shapes to provide crush, where needed; it puts less warping force(s) on the head & cylinder. The heat conduction properties are vastly different between the two types. Then, there's the thickness difference...and what that does to piston clearance, static CR and cam chain tension & cam phasing (timing). One needs to possess a lot of specific engineering knowledge to make the call as to which is best for a specific application. When in doubt...follow manufacturer instructions, unless you a.) have the required custom engine-building experience to insure that everything fits and b.) are willing to gamble that your choice will work as expected.

    57mm bore results in some very thin areas of the head gasket...I don't like seeing that even with a Wave/Nice cylinder, which starts out with wider mating surfaces. That said, you had no issues with it as-built. Seems clear imho that the manufacturer instructions worked...why reinvent them? And, yes, with the info provided, gasket sealer makes a LOT of sense.

    BTW, I like your ring compressor...another example of kirrbby resourcefulness.(y)
     
  4. kirrbby

    kirrbby Well-Known Member

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    Going by the numbers...this motor had a 3mm spacer under the cylinder. And the cylinder was cut down 1½mm. +3 -1½= I should need a 1½mm spacer under a 69mm cylinder to be the same as what it had before teardown.
    So that's what I did. Installed with the old piston, minus rings, all gaskets and spacers to be used, clayed it up and tightened down the studs with 2 fingers on a ¼" ratchet. Cam timing set, and spun it over twice.
    Looks like I have about a good mm clearance...closer to 1½ by my eye.
    I'm thinking I'm good here, but I'm game to use a smaller shim for a bit more compression??
    I plan to add a oil cooler anyway, AND I have the correct pinion gear in it now too.


    IMG_20191102_195132880.jpg IMG_20191102_195156704.jpg IMG_20191102_192523856.jpg
     
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  5. kirrbby

    kirrbby Well-Known Member

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    Oops...my pictures are out of order. Pic #3 should be pic #1...the "before" picture.
     
  6. racerx

    racerx Administrator
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    What you're doing is going through steps that separate successful engine builds from failures. Few understand just how much time, effort and detail-focus is required and it's not surprising...it's anything but glamorous stuff.

    Reading through your post, I can't help but wonder "WTF would anyone want to cut-down a cylinder jug by 1.5mm, then add a 3mm spacer?" Why not just do what you're planning to do, it's simpler & cleaner.

    BTW, I'd not take a chance reducing valve clearance...or increasing compression ratio. Both may be asking for trouble and the engine performed well as previously configured. "If it ain't broke..."
     
  7. kirrbby

    kirrbby Well-Known Member

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    Well, I think what happens(ed)...
    Piston hits head...I need a 1½mm spacer...I have some 3mm aluminum...and a die grinder...and a lathe...I can make a thick spacer....then I can remove 1½mm from the cylinder.
    Viola!..workaround.
     
  8. kirrbby

    kirrbby Well-Known Member

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    I'm definitely learning.
    I'd like to build another engine like this one in the near future. Slightly different...mainly just a tb V2 head instead of the 4 valve. fatcaaat helped me find the correct crank. Once I have that I'll gather everything I expect I'll need to build the whole bike...VERY much the same as this 88 dax. Same or better :D
     
  9. Tripod

    Tripod Active Member

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    This kind of reminds me of paint prep. It aint fun or glamourous, but it pays off.
     
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