Friday, February 22, 2019

Going Back Together

One of the wonderful things about where I live is having one of America's best natural terrain race courses just 30 minutes away from home. Here are some photos I snapped at the July WKA National race at VIRginia International Raceway. 




16 piston port vintage karts joined the modern Yamaha karts


Exciting to see this many karts safely cruising down the main straight


Some things never change in karting, but not the nerves and friendships on the grid

Sadly, VIR decided not to extend an offer to WKA for an event in 2019. I've been told from several sources that the cost of an event is equivalent to purchasing a house and the track would be able to rent the track to other entities for much more.   So it looks like I won't be able to drive on this track.😡


Now back to the Hartman...  

One of the important updates to the Hartman includes adding a second aluminum pan under the seat.  This will meet the safety standards of modern karts in order to keep objects from puncturing up through the seat.  I was able to order a sheet of aluminum exactly the width of the original seat pan, which left the details to be cut. 


After tracing the seat pan, I used the oscillating tool to make relief cuts in from the edge to the cut lines.  It was loud and probably lost a few fillings from the vibration. Then I broke off each tab, filed down all the sharp edges, then wire-brushed every edge.   The new piece fits under the original.  Getting the old and new to line up on the kart took a while, but I was able to drill new holes using the original pan as a guide.  New button head bolts and flange nuts are used...and each has a touch of thread locker.







After trying to clean the front pan, I decided to paint it (and the front portion of the seat pan) with the Dupli-Color MetalCast Aluminum paint.  Then I painted a section with black rubber paint to give some tack and protection from shoes on the pedals.





Just before installing the pans I degreased and cleaned the frame to get it ready for the moment I have anticipated for years: Sealing it with Sharkhide.   I have talked about this sealant before.  Many thanks to SteveO!!  The frame is gently polished.. and looks great.  :-)

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[have I mentioned this is one reason I love where I live? The sound of Freedom]



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Many earlier posts deal with polishing the tanks.  Yea, there is a reflection, but not very clear. 


Then I broke out the Mother's Aluminum Polish and buffed them by hand.  I am totally amazed at how quickly it works with just a little elbow-grease. 
That's a pretty good finish!

But I found some deep scratches from using the big, clunky sander.  GRRRRRRR....  
Here is the large tank.  WOW!



Here is the small tank.  WOW!
Next step will be to first spray on the MetalCast Adhesion Promoter then the MetalCast Blue Anodized paint.  This has to wait for a warm day with low humidity to keep condensation from making the paint splotch and run.    

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When Colm O'Higgins gave me the Hartman kart, several other pieces came with it, including two engine mounts.  During the work-days at Rick's we discovered the mount which fit the kart (axle-to-support) was shaped for an engine on the left side. It interfered with the axle clutch.  The other didn't fit (axle-to-support), but was the correct shape.  Then I had a revelation...  Just put the front support block on the correct swing arm.  EASY!!  Wellllll.... not so fast.  The bolt holes joining them didn't match up, so that means creating new holes...very precisely...and then tapping them...which I had never done before.  That's the one thing I dreaded during this entire process.  One mistake... and I'd need to find a new swing arm.  (as I write this I wonder if I could have just flipped the aluminum over. hhhmmmm)


This is the block close to its intended placement. Notice anything?

Yep... the notch on the front outside is directly under one of the bolt holes.  Due to the vibrations and weight of the engine, this block MUST be 110% secure...with four bolts.   

 

The exact location needed to be found and marked. The swing arm needed to be exactly 90º to the axle. I used a large drafting triangle to align it, then marked the holes.


 With the three holes marked, I could start the process to drill, then thread them.






Then to tap the three holes, which went pretty smoothly, even without a proper tap handle.



What to do about the fourth hole? There were several obstacles: The edge of the  swing arm base; the large, 5/8" hole through the block; the existing hole in the base.  There was just enough open space between all three to drill a new hole. It is close to the corner so it will hopefully give nearly the same strength.

The fourth hole would be the same size as the others, smooth in the block, then threaded through the base.  The first 1/4" in the block would counter-synced to allow the bolt head to sit flush. CRAP... I got over zealous and drilled all the way through!  I had to go through the whole process again to fit a larger bolt. It looks huge! But it works.




There it is... ready for the engine. 

Well... not so fast there, Bub.  Further on in the process, while dry-fitting bolts and collars, I realized the mounting block needs to be locked in place with locking collars, one on each side. But this aluminum base interferes with the inner collar. I will have to cut the plate back to the block. 
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This is the pipe I purchased at Comet Kart Sales for $20.  It was very rusty... but vinegar is our friend. I soaked it for an hour in another container before transferring to this sink. Soak, scrub. Soak, scrub.


It turned out pretty good. Dried with a torch, then oiled to prevent more rust. 

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When I received the kart all the steering components had been blackened.  I would rather to have them back to their original, shiny condition.  Like this shot of a KH kart of similar vintage: 


Close-up of the black finish
I took apart all the steering components and investigated ways to remove the blackening. As stated earlier, vinegar is our friend.  After washing them down with degreaser, they were put into a vinegar bath. 




After first round of vinegar
The spindles were not totally degreased before the vinegar bath which caused some texturing of the surfaces, but they will be mostly hidden by tires, brakes, and brake disks.


I sanded the textures just a bit to knock down the highest spots, and brushed all surfaces with the brass wire wheel on the grinder. Then I hit it just a tad with Mother's Polish to put some luster in the surface.  And, finally, Sharkhide to top it off. 

I did the same process, though not as long, with the pins and nuts.

A little time on the brass wire brush on the grinder and they look brand new.


The spindles went on the same way they were removed: with a little help from Mr. Vice.




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Next was the pedals and all their bits & bobs.  Cleaned up with 409 degreaser, then into the vinegar. 

That did a good job of getting most of the black off.


But it is always better with a good brushing... 


Much better! I don't want a show-kart, but shiny is better then dull.  I did investigate home DIY metal plating, but this is getting there already.

I hit each pedal and rod with some Mother's Metal Polish for a final shine.  WOW!  Then a good coat of Sharkhide. 

 The throttle went on first, with the help of both elbow grease and lithium grease.... and some gentle nudging.