The Quarter Scale documentation suggested machining scaled AN816 37 degree flare fittings for connecting the oil lines to the relief valve housing. For the housing's two output lines I machined a pair of single piece flanges that were intended to only look like threaded fittings. I used faux fittings on these two lines because the runs made up from the rigid tubing were just too short and didn't have the flexibility required to undo a threaded connection. One of my goals in plumbing the oil system was to do it in such a way that the individual lines can later be opened up for maintenance (to verify flow, replace gaskets, etc.) without the need for a lot of secondary disassembly.
Three additional oil lines branch off the far end of the low pressure line at the rear of the engine. These lines feed oil to the internals of the wheel case as well as the camshafts and rockers in the engine's top end. Unfortunately, they need to be routed in the busiest section of the engine and right up against the chain cover and starboard-side distributor.
A sketch in the Quarter Scale's documentation recommended anchoring a stack of banjo fittings to the top of the wheel case to create a union for these lines. In my particular case, this would have required some heroic bends in the 3/32" copper tubing used for the lines. Several days were spent trying to come up with something that looked decent but was still accessible. Bare aluminum (tig) welding rod and lots of trial-and-error was used to develop shapes for these three oil lines. Simple grooved mandrels turned from wooden dowels were used to form the bends. Along the way, I machined lots of brass fittings that ended up not being used. One batch of parts ended up being inadvertently machined from the nasty mystery brass that created so many problems for the crankshaft oil manifold.
I wanted the flanged fittings that were used at the rear of the engine to be as small as possible, but their mating surfaces needed enough area to provide leak-free joints. I didn't want to use sealer on any part of the oil system for fear of it finding its way inside a tube and creating a blockage. The tubes were soldered to the fittings with a tiny butane torch while they were bolted onto the engine in their final positions and with their sealing surfaces parallel and making full contact. The challenge while forming the complex bends was to not only make them pleasing to the eye but precise enough so they slipped easily into position.
Eventually, I created a custom union for the four lines on the starboard side of the engine just forward of the distributor and barely out of the way of its plug wires. Yet another set of fittings was machined to accommodate the bends coming out of the union. A really troublesome line needed to be run to the input fitting on the top of the wheel case. This single line created 90% of the rod and tubing scrap shown in one of the photos. The union isn't rigidly attached to the crankcase but is well supported and held in position by the four tubes attached to it. This was done to reduce the stresses on the solder joints. After all the oil lines were completed and finally in place, each was removed, one at a time, so linen paper gaskets could be added.
Those who have been following this build, and didn't like my brass relief valve housing, may not like the brass union either.
It's bigger than I would have liked, but it will be hidden behind the distributors and plug wires when they are installed. - Terry
