I needed an oil tank for this build that would be rather unique. It had to hold a full size battery from a late model electric start Dyna or Softail as my large high compression stroker motor would need all the starting power it could get. It had to completely hide the battery because I didn’t want any of it to protrude above the frame rails and it had to hold lots of oil.
My preference was round oil tanks so I started looking for cylinder like containers to see what size might fit.
After testing a variety of ice cream containers and my wife’s Tupperware I found a one gallon paint can to be perfect. (once I cut the bottom out to clear the electric starter)
The first step in making the oil tank was to fabricate a battery box. I used some 14 gauge sheet metal and bent one up on my brake and then welded in the sides. The batteries I use are the late sealed type so they can be placed in any position. This one was going to lay in at an angle to miss the electric starter.
With the battery box out of the way I used some more 14 gauge sheet metal and rolled up the tank on my 3 roll machine.
I cut a rectangular piece out of the tank shell and welded the batter box inside the tank. Now you can see why I wanted such a big tank, that battery box displaces a lot of oil holding capacity.
The under side of the tank had to be notched for electric starter clearance.
With the oil tank shell part taken care of it was time to make some tank ends. I wanted my ends flat so i could later bolt on polished aluminum covers.
After plasma cutting the ends out I drilled holes to mount them in my lathe and turn them round. I need perfectly round ends to help pull the tank shell into shape as i tack welded everything together.
Before welding the ends in place I had to weld two threaded blind bungs in the back sides to attach my aluminum side covers. This was a little tricky as the threaded holes needed to be parallel with the fins on my motor’s right side timing cover as I planned to machine matching fins for the oil tank end cover.
Lower front oil tank mount is hinged to flip up for easy removal. If I need to work on the starter, the oil tank must come out.
Oil tank top mounts are countersunk for Allen cap screws. I do this with all my mounts so I am not tightening bolts and washers against paint.
Time to make those oil tank end covers.
The left side cover had to be notched for the starter drive.
Right side cover test fit and oil tank filler welded in and capped.
I machined and radius cut the exact same fin pattern as the engine timing gear cover on the right side cover. The left side cover was easy as it was all done on my lathe.
I think it was all worth the extra effort.
