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This interesting engine was believed to have been built by the famous Australian engineering firm, Wm Olds & Sons Pty Ltd, of North Street, Maryborough QLD 4650. OLDS ENGINEERING is stlll actively engaged in the industrial and marine fields. The present Managing Director is Mr. Peter Olds, a son of the founder William Olds, who commenced operations in 1918.
The OLDS crankcase is a gravity die-casting, indicating that some production was envisaged, or may in fact have taken place. The engine is very well made and fitted, having excellent castings and hardened parts. Although the basic design is typical of other engines produced in the period from 1934 to 1938, the OLDS has several innovative features.
One of these is an adjustable transfer passage, an idea I have not seen on any other engine. A blade is moved across the transfer port by the action of a screw-thread and knurled nut. Obviously intended to control power output by limiting the transfer opening, its effectiveness is not known. Another sensible feature is the inclusion of a castellated steel lock ring, which ensures a positive and firm cylinder to crankcase joint. A special spanner would have been required to tighten this lock ring.
The aluminium piston is fitted with two compression rings and the hardened and ground steel crankshaft runs in a single, rear ballrace and a bronze bush. Most exposed steel parts on the engine are nicely cad-plated to inhibit corrosion. The rear-mounted tank appears to be from glass tubing. As the firm was and still is involved in steam work, it may have been sourced from a sight glass.
Missing on my example are the exhaust manifold and the complete timer assembly. Judging from the size of the integral ignition cam, I would guess that the timer probably used a moving point from a Ford V8 set.
I wrote to Peter Olds in April 2001, asking if he could provide more information about the engine. A prompt reply was received and in his very nice letter, Peter confirmed the following:
The engine was produced by his late father just prior to WW2, one of a small number he made using a die-cast crankcase. A test-rig was made in order to evaluate various modifications. Though a young boy at the time, Peter recalled models being flown with his father's engine in the Maryborough area. He mentioned the late Roy Ullman, who won the Australian Championship Competition (sic), held in Bundaberg in 1938 or 1939, using an OLDS engine. Following the war, one or two engines were run with glow plugs, but these were thought to not have the same advantages as spark-ignition. Also included with Peter's letter was a cutting (thought to be 1938) from a local Maryborough paper, in which it is noted that three engines made by William Olds were used in a recent club competition. These engines were given a most satisfactory comment.
No other OLDS engine is known to exist, but hopefully other examples of this fine Australian engine are out there somewhere. The writer is very keen to obtain photographs of the missing exhaust and ignition timer in order that this unique engine can be properly restored to running condition.
David Owen, Wollongong, May 2011