Stock Built 6 Cylinder Radial Engine
USA - Manufacture date: 19??
Bore =1/2", Stroke 1-" , Flywheel diameter = 4"
Style: Double Acting, Oscillating Radial Engine

Dimensions: 4" length x 6" width x 6" height

The Restored Radial Engine

Sometimes you get unexpected results. Such was the case with this unusual little hand built 6 cylinder radial engine. I've occasionally taken on  restoration projects for other peoples' engines. (Before you send yours... know that I'm selective, I don't do it often, I don't cut corners and I don't do it cheaply or quickly) One of these owners sent me this engine because he'd heard I was watching for a radial to add to the collection. He wanted to trade it for the labor to restore one of his vintage Jensen engines. When it arrived, it was not an engine that immediately made a good impression. As the photo shown below indicates, it was a bit plain, not all that cleanly built,  and ... if it is acceptable to call a gift...well.... UGLY...(grin).. it was. However, it was a wonderful gesture on my friend's part and I accepted his trade.

When I ran this little fellow, I quickly learned that it needed work. The exhaust ports were drilled at the end of each of the legs of the "star" and they blew steam oil in a 360° arc... all over anything within a couple of feet of the engine.

I spent a few days looking at the engine and trying to determine the best way to gain control over this unpleasant tendency. As I took the engine apart to begin clean up, I studied the engine closely. The obvious problems like holes drilled through in places they should not have been and variances in placement of the exhaust ports were carefully noted. Half the battle with beginning any restoration is trying to visualize where the project will end up.


 The Radial Engine Before Restoration

The whole body of this engine acts as a steam distribution manifold. Each leg of the six pointed "star" picks up steam from a circular channel cut into a round disk on the flywheel side of the engine. The main steam inlet is located on the pedestal which feeds the circular channel. This circular manifold was to become the key to fixing the problem, although it took a little while for it to become obvious.

A detail view of the Exhaust Modifications

It finally dawned on me that the outer edge of the circular manifold was a natural place to run a copper exhaust line. It could then direct the exhaust to a single point where it could be collected, beneath the engine. The photo shows the new Head and Exhaust line assembly which was created for each leg of the manifold. The brass lines were then shaped and tapped into the main copper line to form a kind of circular header arrangement.

Each piece of brass was hand formed, fitted and shaped in order to compensate for variations in the existing port placements. The acorn nuts were added to plug a few runaway drill holes made by the original builder.

 Another View of the New Exhaust System

These two views show the finished engine. The brass assemblies were silver-soldered together and then bolted to the main copper line, using 2-56 hex head brass bolts. The flanges were hand ground from 1/8" NPT brass pipe.

 The Rear View of the Radial Engine

The addition of a spoked flywheel (an old Jensen that was cleaned up and polished) to replace the plain solid aluminum slug it came with, a bright red paint job, a polished brass shower bezel and a lot of hand polishing of brass, bronze aluminum and copper transformed this unusual piece into a rather startling improvement over its original condition. The Radial Engine runs quite well on as little as 10 pounds of high volume air and almost appears to be "alive" when the 6 cylinders are seen oscillating together

I'll always look at the rougher engines a little more carefully from now on. I'd have probably passed this one by, in the normal course of events. In doing so, I'd have surely missed out on a great hidden treasure. It sure turned out to be one of the sharper pieces in this eclectic gathering of engines that I call a collection. Thanks Grumpy!!

Stuart Beam  -  Reeves Tangye  -   Williamson   -   Stuart H9   -   Stuart D-10   -   Jensen 51
"Minnie"   -   Cretors D  -  Lewiston High   -  Radial  -  Elbow   -  Rectilinear   -  Curved Cylinder
Böhm Stirling  -  Water Pressure  -  Coomber Rotary
Toy  Engines   -   Turbines
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