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Author Topic: Waconia Charity Build 2016  (Read 130579 times)

dirtman

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Re: Waconia Charity Build 2016
« Reply #195 on: August 26, 2015, 06:11:46 pm »
No question Wankel was the right man for the job! 8) Nice work :)

Well yaaaa!   ;D. Only the best on this project!   ;)

dirtman
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    black cat 68

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    Re: Waconia Charity Build 2016
    « Reply #196 on: September 02, 2015, 11:33:34 pm »
    Very nice pictorial and explanation of the tear down and rebuild.  Now i see what i've been doing wrong, your supposed to have a clean area to work in.  :)

    Rex Rules

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    Re: Waconia Charity Build 2016
    « Reply #197 on: September 03, 2015, 03:26:58 am »
    Um I've known dirtman for 5 years and that's the first time I seen his shop clean....lol
    I got some stuff...............

    dirtman

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    Re: Waconia Charity Build 2016
    « Reply #198 on: September 03, 2015, 10:34:18 am »
    Um I've known dirtman for 5 years and that's the first time I seen his shop clean....lol

    Thinkn Kujo is talkn bout wankel, not me,,,,,,,   just cuz DeVere keeps yours clean!    ::)

    dirtman
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    wankel303

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    Re: Waconia Charity Build 2016
    « Reply #199 on: September 03, 2015, 06:18:27 pm »
    I have two, very, very messy workbenches.  I just took the photos someplace where the countertops were cluttered.  Kitchen countertops, dining room table, basement freezer....well, pretty much anywhere except on the workbench.




    dirtman

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    Re: Waconia Charity Build 2016
    « Reply #200 on: September 09, 2015, 03:26:42 pm »
    Got a cash donation from mtstarfires when we were at Princeton, THANKS Kenny!  8)

    dirtman
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    wankel303

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    Re: Waconia Charity Build 2016
    « Reply #201 on: September 15, 2015, 03:13:45 pm »
    I set up to time this engine  using my usual, favorite timing tools.  JLOs are a bit on the tedious side to get timed just right but they're not hard, in fact, it's darn near impossible to goof 'em up.  Unlike some other engines that have a tight tolerance for timing, the JLO certainly does not.  It's a Bosch System, not uncommon among the old German built engines.  Timing specifications are listed in the OEM Service Manual as follows:

    Contact point gap: 0.014" to 0.118".
    Timing: .118" to .138" BTDC w/advance cam pinned in fully advance position.  You will have to pin the timing advance cam in the fully advanced position and there is hole in the flywheel specifically meant for this.

    Both of the above specs give you a wide working margin in fact, I have often wondered if the Service Manual wasn't a typo regarding the 0.118" point gap as this seems huge and I have never, ever needed a point gap that large to time an engine whether I am using aftermarket points or OEM Bosch points.  Typically, you'd see 0.014" to 0.018" in a Hirth or Sachs service manual. 

    Setting the points is probably the second most tedious step in this process. JLO didn't give much room to do this through the windows in the flywheel compared to other manufacturers. Again, as I said, it's a Bosch system but Bosch only makes the internals of the flywheel; JLO makes the cast aluminum part of the flywheel and governs how much space is needed to access the points.  With the flywheel installed, there are two windows to adjust the points; one to make adjustments and the other to measure. 

    Here is the window to make the adjustments:



    And here is the window to measure:



    It's easiest to set the points somewhere in the middle of the adjustment range on the points and work from there.  From here, it's a process of rocking the flywheel between the two windows making small adjustments then measuring....adjust again...then measure...etc....repeat until you measure a point gap with the specified range.  In this instance, I set the points at 0.018"which is where I usually set the Bosch systems.  It's on the high side of the range ( at least in my opinion and per other engine service manuals besides the JLO one) and I do this because the cam follower will wear over time causing the point gap to become smaller.  I'd much rather the points wear into the specification range than out of the specification range.

    Once the point gap is set, it's time to set the timing.  I use a Motion Pro dial indicator for almost all of my engines but there are other dials out there that work equally as well.  This has a 5mm linear range.  The threads on it are  14mm so they fit most engines but the plug on most of these big singles is an 18mm so I need to use my adapter.  I also needed to use one extension to reach down into the combustion chamber.





    I use a Gardner Bender GMT -319 mult-imeter as my buzz box.  This is an variable tone, audible, continuity tester which, in my opinion, is critical to engine timing.  You can get these at Menards quite reasonable.



    Add in a couple of jumper wires, one connected to the black lead from the engine magneto and the other connected othe case, and we're almost set-up .



    Roll the engine to TDC and set your timing gauge to the maximum, 5mm.  So at TDC, the gauge is reading 5mm.  Now we have a little conversion to do since the timing specs were SAE units and the gauge is metric.  My timing BTDC measurement range is .118" to .138".  The middle of this range is .128" and that is going to be my target.  This converts to 3.25 mm BTDC.  Again, I much prefer to be within the specification range than on the edge of it.  As I mentioned, the cam follower will wear with time decreasing the point gap and with a smaller point gap, you'll also see a small change in timing towards the retarded side.  So by being within the range of timing, the engine won't wear to a condition where it's out of time. 

    The adjustment for timing is made by rotating the entire stator assembly.  This requires loosening the three screws that secure it to the engine cases.  As with the points, I usually begin at the middle of the available adjustment range.  Install the flywheel ( just set it in place without tightening the nut so you can remove it by hand without using a puller) and rotate the engine counterclockwise until you hear a tone change in the multi-meter...then,..keep going alittle further.  Then rotate the engine clockwise and watch the timing gauge closely while listening to the buzzer.   By rotating it clockwise, you take up the tolerance in the bearings and duplicate the same condition it would see when it was running.  The benefit of the buzzer is that you don't  have to watch two things at the same time ( if you were using a timing light instead of a buzzer).  From here, it's a series of adjustments to get it timed just right.  I probably had the flywheel on and off three or four times to get it timed.  I turned the continuity tester off between adjustments because, well, it'll drive you crazy.  Kinda like a mosquito in your ear.

    My target was 3.25 mm BTDC so the gauge should read 1.75mm when the tone changes ( 5 mm - 3.25 mm = 1.75 mm).  I ended up at about 1.72-1.73 mm BTDC which  translates to about .129" BTDC.  In the video below, note that the tone changes at 1.75 mm on the counter clockwise stroke but 1.72 on the clockwise stroke.  This is due to that tolerance in the bearings that I mentioned.

    http://vid669.photobucket.com/albums/vv57/mlackore/JLO%20297/20150914_204016_zpshfimpyqr.mp4
    « Last Edit: October 06, 2016, 01:18:31 pm by wankel303 »

    mtstarfires

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    Re: Waconia Charity Build 2016
    « Reply #202 on: September 15, 2015, 03:35:12 pm »
    so milt, how about some pics of the pretty blue parts i saw at your place. ;) ;) ;)   ken

    wankel303

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    Re: Waconia Charity Build 2016
    « Reply #203 on: September 29, 2015, 01:02:28 pm »
    This engine has taken the title of the "greasiest engine ever"   I've seen a lot of greasy old engines in my day but this one has taken the cake.  It makes 'em easy to work on since everything underneath the grease is like brand new but man-o-man, have I spent some hours scrubbing!   

    dirtman

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    Re: Waconia Charity Build 2016
    « Reply #204 on: September 30, 2015, 11:33:21 am »
    Minni-soda cosmolin...........

    dirtman
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    wankel303

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    Re: Waconia Charity Build 2016
    « Reply #205 on: October 08, 2015, 02:40:43 pm »
    With the timing set, I double checked the torque on the case screws, cylinder base nuts and re-applied the torque to the head.  Once everything was checked off, I installed the flyhweel nut hand tight.  Just as a precaution, I always check for spark before I torque the flywheel nut in place. It's tough to do with the fan shrouding on and just spinning the flywheel by hand should be fast enough to generate a nice, bright, blue spark.  I clicked off the workbench light and gave it the "wheel of fortune" spin and I was quite pleased with the quality of the spark.  Test complete, I tightened the flywheel nut to spec.



    Once the flywheel is on, the fan shroud followed by the starter cup get installed. 





    I thought I had taken more photos of the next steps but I couldn't find the photos on my camera when I went to upload them.  After the starter cup installation, I spent some time cleaning up the cylinder head shroud, phenolic intake adapter and I scrounged up the gaskets for the intake and exhaust.  There are two gaskets each for the intake and exhaust; they basically sandwich the cylinder head shroud.  The exhaust gasket needs to go on before the head shrouding but the intake gaskets can be installed afterwards.  I find it easiest to align one hole on the intake gaskets ( lining up the screw within the phenolic adapter holes with the gasket-shroud-gasket-cylinder.) then starting the screw enough to hold it all  in place.  To get the second screw aligned, use your fingers through the adapter/intake to get it all lined up.  I'll take more photos tonight to update this process.

    The engine is fully assembled now and the next, last steps are a rebuild of the recoil assembly and Tillotson carburetor.  Stay tuned.

    « Last Edit: October 08, 2015, 02:53:30 pm by wankel303 »

    dirtman

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    Re: Waconia Charity Build 2016
    « Reply #206 on: October 10, 2015, 12:10:25 am »
    Can't wait to hear it PURRRRRRR!

    dirtman
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    wankel303

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    Re: Waconia Charity Build 2016
    « Reply #207 on: October 12, 2015, 09:30:13 pm »
    One of the last parts to rebuild on this motor is the recoil.  These are always a bunch of fun but fortunately, there have been ample parts donations for this portion of the project.  There was little that I needed to re-use and the critical stuff was all new.  The JLO recoil, for me at least, has been one of the lesser troublesome recoil designs in my fleet of machines.  I think I have had the most issues with the Hirth style of recoil design.  The first step in the disassembly is the removal of the cover plate.  Just four small machine screws and it comes off.



    In the photo above I actually flipped the cover plate over after I removed so you can see the tracks made by the friction cups.  The JLO recoil uses a unique spring-clip design to activate the pawls but it relies on friction first and foremost.  There are two springs and four cups of two sizes that ride on two plates, a top and bottom.



    If you ever remove a cover plate and only see one spring-cup assembly, look at the underside of the cover plate.  They often stick in their wear grooves and come off with the plate. Both plates should be clean and grease free.  The pawls just rest in place on two large pivot pins.  Again with the overbuilding, the pawls are big brutes and pretty heavy duty.  The single tooth on the very end is the only area that I have ever really seen wear.  These two pawls were in good shape so they were reused.   Pawl retraction is acheived by two small wire springs, one for each pawl,  with creatively formed/bent ends to prevent them from coming loose. 



    The four small machine screws are the only fasteners used in this recoil and once the pawls are out, the bottom plate lifts straight up and away.  Again, I will scrub this up very well before re-installing it. 



    The pulley is exposed now and the first temption at this point is to just lift it out of there.  DO NOT REMOVE IT.   There is about 1 1/4 turn of pre-load applied to the ribbon spring beneath it and it's a strong spring.  Lifting the pulley out at this point is a sure fire way to make it go "fffwoooing" into a ball of twisted ribbon like spring steel.  The recoil has had rope installed in place of the steel cable and this will not hold up.  These recoils need that steel wire.  I had no intention of saving the  rope so I puilled the cable end out from the back side of the handle and cut it off.  Just make sure you hold onto the rope (or keep the pulley from turning) when you cut it because it'll want to be drawn into the recoil.  The cable end is a round wedge style of cable end is identical to those used by Hirth.



    There is a rubber bumper and a plastic stop that is threaded into the recoil.  The rubber stop is supposed to be attached the recoil handle and the plastic stop will need to be removed.  You can leave it attached, but it makes it difficul to thread the new cable when you're re-assembling it because the hole in the middle isn't much larger than the cable diameter.



    Now you can slowly release the pre-load on the spring and let the rope wind up on the pulley.  When the tension is removed, carefully lift the untensioned puller from the housing just about 1/4 or so.  There is a small hole, maybe 3/8" diameter, where the end of the ribbon spring is recessed within from below that is accessible from the exposed side of the pulley. Use a small screw driver to push the rolled end of the spring from the bottom side of the pulley.  In the picture below, you can see this hole to the left of the center hub.



    If you've lifted the pulley too far, the ribbon spring will come out with that "fffwooing" sound that has to be one of the most sickening sounds a vintage sled guy ever has to hear.  I was lucky with this one and it stayed put but then I realized that I had new spring and and a new housing.  It would have been easier to leave the old spring in there and re-use the housing.  The new spring came nice and neatly packaged with a wire retainer keeping it wound nice and small.  I was very careful to set in place, secure the loop on one end of the spring with the pin on the housing.  Holding it tight I carefully slipped the wire off and voila!!....it was in.  Piece of cake until I turned my back and it heard that sound.  It took me four attempts to re-wind it small enough it by hand and get it back in there.



    I set it asside with the slow and careful motions of someone handling an armed 10 megaton nuclear warhead then focused on the rewind pulley and cable. 

    I added a generous dollup of low temp grease to the hub before I wound the wire rope onto the pulley. 



    Your cable must be fed onto the pulley from the topside.  There is a lip on the end of the round end of the wire rope that will rub/bind on the housing if you install it from below.



    I wrapped the wire rope around the pulley as tightly as I could by hand and when I reached the end, I used a peice of duct tape, 2 inches long or so, just barely wrapped around the backside of the pulley and an inch or so before the bare end of the wire to hold the wire rope below the OD of the pulley.  I used a second, smaller peice applied in the same fashion to push that last 1" down within the groove of the pulley.  You need to do this so you can apply the pre-load to the ribbon spring.  The duct tape needs to be removable so don't secure it too well to the backside of the pulley. 

    Once the tape is on, carefully retrieve the housing and spring.  You may have to bend the inner end of the spring slightly to get it to aling with the recess in the bottom of the pulley but once it drops int there, you're set to go.  I used a small allen wrench through that same 3/8" to align the end of the spring with the recess.  Now that the spring is engaged in the pulley and it's dropped fully into the housing,  turn the pulley counterclockwise about 1 1/4 turns.  Once the end of the wire rope and the duct tape aligns witht the passage through the housing, remove the peice of tape from the end.  The remaining 1" or so will stand up above edge of the pulley.  You can now continue to rotate the pulley counterclockwise to feed the wire rope through and since there is a second peice of tape holding it, the wire rope won't back up on you and bind between the housing and the pulley.   Once the wire rope is through, remove the last peice of duct tape.  Unfortunately, you need both hands for this so I couldn't take photos.  Once the rope was through, I used a screw driver through another hole in the pulley to keep it from losing tension.



    As long as that screwdriver doesn't let loose, it's a cake walk from here.  You can feed the wire through installing the plastic stop, the rubber bumper and the handle. 



    Fold the wire over on itself as tightly as you can then install the wedge -style cable end int the recoil handle.





    From here you can re-install the bottom plate, the pawls, friction cups & springs, and finally the cover/top plate and it's all done.

    « Last Edit: October 12, 2015, 09:33:40 pm by wankel303 »

    exracer

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    Re: Waconia Charity Build 2016
    « Reply #208 on: October 12, 2015, 11:32:09 pm »
    Wankel 303 definetly know his JLO's... I'm building the same engine, and have had to get his input on timing, and a few parts. I can't say enough good
    things about him. Keep up the great work!

    dirtman

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    Re: Waconia Charity Build 2016
    « Reply #209 on: November 02, 2015, 11:54:35 am »
    Well boys n girls... gettn to be time to put the Larson back together! Lookin at a couple of dates, Nov. 21St, and Dec 5th. I'm sure there might hafta be something early Jan. also but shud go pretty good!  My lap top had a major malfunction, and I'm runnin a tablet n a smartazz phone. Wayyyy to high tech for an old fart like me and I haven't figured out how to post pics of all the pretty parts!  :-[    EVERYONE is welcome to come join the fun on one of these dates!  and you local yokos know where I live if ya go a spare evening.     ;D

    dirtman
    a bunch of Polaris's   PETT # 85