Model Engine News: December 2002

 

Editorial

Last month I started by saying that Yet Another Month had passed with No Activity In The Shop, and now it looks like an entire year has slipped past as well. At least there was some minor shop activity this month with the spinning of some fuel tank ends for a Brown model B that came my way. Metal spinning turns out to be easy, fast and fun. It will get some pictorial coverage as soon as the current workload eases -- hopefully following December 13. So let's see what I can ramble on about...

Magazines and Books of the Month

The fourth and final issue (for 2002) of Torque Meter arrived during November. This is the journal published by the Aircraft Engine Historical Society. Content includes more of why the designers of the P-38 chose to rotate the engines the way they did, plus historical background on the Packard Company's aero engines and a technical piece on the RR Merlin supercharger drive mechanism. The issue also contained results of a servey conducted earlier in the year indicating that "A surprising number of members are model engine collectors and builders." I'm not so surprised. There are very few places we (the model engine collectors and builders, that is) can go to get a fix these days...

Noise Complaint

During the month, I received a request to use some of the material about Lawerence H Sparey from this site in a printed publication. I'm always happy to do this, provided correct attribution is included (call it vanity) and the request had the side benefit of driving me to an evening in the "library" searching for the obiturary notice I was sure I'd seen in an issue of Aeromodeller. This took longer than expected, but the sad notice was finally located in Aeromodeller volume 51, Issue 611 of December 1986 - a lot, LOT, later than I'd thought, considering that LHS disappeared from the pages in 1952.

Armed with this, I hit the Model Engineer stacks and found another notice in ME vol 157, Issue 3789 of November 1986. The ME Vale was considerably more detailed than that in Aeromodeller; which I find sad considering the work done by Sparey testing engines for Aeromodeller in the late 1940's and early 50's.

Model Engineer reported that LHS passed away on July 14, 1986 at the age of 86, meaning he was born in the 19th century (provided you are not of the year zero == new century school). The writer also shed oblique light on why Sparey stopped writing his engine test reports for Aeromodeller. It appears that he lived in North London (his name is mentioned on the web site of the North London Model Engineering Society, though no other historical material on him can be found there). His engine tests were apparently exhaustive with many hours needed to fully break-in the engine, then collect test figures under different conditions to aggregate the results. It seems he frequently conducted these tests at night, and it was this activity that brought the wrath of the local council down on his head. This resulted in what was probably the first formal anti-model engine noise complaint of our era! As a result, he was forced to cease engine testing for Aeromodeller. Read as a poetical twist, we can therefore credit Sparey with yet another first related to model engines for the United Kingdom.

External Combustion

Alas, live steam does nothing for me, although I can and do admire the work and dedication that goes into building a steam locomotive. I've even dabbled myself, building some Stuart Kits in exchange for IC castings, but I have no burning desire to make any for myself, as yet. This is mentioned because of the pages of ET Westbury's work I've (digitally) scanned this past month. In addition to his well known work on all mannar of IC engines, ETW wrote on boiler construction, marine propellor design, steam driven fire-engines, and flash-steam engines. In fact, one of his flash steam engine designs--a three cylinder radial with orbital porting called the Royal Cygnet--was adapted to a high speed air driven tool.

A New Motor Boys Plan

The Motor Boys International CAD plans for the Belmont G9 are taking shape with all components drawn and the design modified to simplify construction somewhat and get the timing into a more reasonable corner of the ball park. Bert Striegler in Texas managed to borrow an original engine and dismantle it sufficiently to photograph the parts, blow-up and print the images and pencil dimensions on them. This is a new idea of Bert's and it has worked very well indeed. What we discovered was a very wild inlet timing of about 145 degrees. The G9 is piston ported, so all timings are symetrical. This has the inlet opening just 107 degrees after BDC, which means that the pumping action is going to be just about *nothing*.

I derive my timing figures by drawing the components to full, or twice full size in TurboCAD, placing them all together for the General Arrangement (GA) drawing, then measuring the distance from the center-line to the port openings. These figures, plus others like piston height, wrist pin location and conrod length are entered into a spreadsheet that applies some serious trig equations to spit out the timing figures. Bert was so skeptical of the results, he put a degree wheel on the prop hub and used a strong light to physically measure the timing. We got the same results, within a degree, or so.

This just goes to show how really *crappy* some of those golden age monstrosities were. The designers (pioneers though they were), seems to have known and cared little about R&D -- almost like some software developers today -- "..we've got one the runs--ship it!" Anyway, by lowering the rear of the piston skirt, and redesigning the tank/backplate, we have the inlet down to a workable 110 degrees and an engine that will retain the external looks of the original, but actually draw fuel as well. All that remains to be done is dimension all the sheets--which means only about 70% of the effort remains!

I Feel the Need...

Another email last month came from David Burke as one of the founders of SPEED Inc (see the tenuous connection to the heading now?) SPEED expands out to the "[The] Society of Persons Encouraging Engine Development". They are located in Adelaide, South Australia and annual dues are a mere A$20.00 ('though I'd expect participation in a construction project would reasonably entail additional contributions). As the name suggests, this group builds project engines and teaches new members the tricks which are in danger of dying out. They also arrange for group processing of parts, like casting and case hardening (very usefull!) Membership is probably of reduced worth to non-local folk, but several of their projects are Taipan reproductions and I'll forgive almost any sin for that. If the web site content seems a bit rule-bound on first glance, you need to understand the "Inc" part of their name. In Australia, as elsewhere, "Incorporation" provides protection to individual members from overly litigious aggrieved parties, at the expense of a constitution and an annual audit. So don't be put off by the apparent formality; checkout the site, ignore the numbered paragraphs and look at the pictures and the projects.