Model Engine News: May 2005

   Vale: PGF Chinn
   Cirrus Progress
   Hydra: No More Excuses!
   RCS 400 Radial
   Yet Another Faux Twin
   Model Engine Builder Ships!
   Sky Charger
   Cookie Cutters
   New Hobby Shop in Beenleigh

   Editorial
   New Books and Magazines This Month
   Engine Of The Month: ZOM!
   Tech Tip of the Month (1): Multy-throw Cranks
   Tech Tip of the Month (2): How To Knurl Prop Drivers
   Standard Stuff

Editorial

The engine review this month is a bit lightweight, but there are two Tech Tips to compensate. I'd wanted to review the first issue of Model Engine Builder too, but it arrived in Australia just one day before "press time", so it will have to wait for next month. First more sad news...

Vale: PGF Chinn

I'm sure that everyone who loves model engines would be aware of the name Peter Chinn, and will be saddened to learn of his passing on April 7, 2005. Peter, whose writings span about 50 years in the modelling press on both sides of the Atlantic, was born on July 2, 1921. He, and his brother, began aeromodelling before WW II, building stick and tissue scale models. As far as we know, his first published feature was simply titled "Model Aircraft" for the May 1940 edition of Boys Own Paper. The last I could locate was a full engine review of the OS 46FSF-S that appeared in the April 1989 issue of Aeromodeller, but PGFC was so prolific, this may not be the last word.

Most will associate Peter with the meticulously detailed and insightful model engine reviews that that he prepared. His first engine was custom-built during Army service in 1946 and tested aboard a motor-launch off the island of Giudecca in Venice. While serving in Italy, he bought some early Italian diesels. These were followed by various American spark and glowplug engines of the period. To satisfy his curiosity on their performance, he devised his own testing rig and his findings were published in the British modelling press. As a result, he was asked by several manufacturers to carry out prototype testing, and by the editor of Model Aircraft, to contribute a regular series of reports.

Peter was one of the most prolific writers this hobby has seen. The Index of Engine Reviews on this site currently lists 688 full engine reviews directly attributed to him. In the process of researching for this tribute, I "discovered" another box of uncatalogued issues of Model Airplane News that added another 137 reviews, all by Peter, for the period 1982 to 1988. This figure incidentally does not include the multitude of engines he covered briefly in his numerous monthly columns in equally numerous magazines.

His knowledge and reporting was not restricted solely to model engines. In addition to his writings in the British magazines Aeromodeller, Model Aircraft, and Radio Modeller, he contributed a monthly column on general model aviation development to the American magazine Model Airplane News. His first Foreign Notes column appeared in the March 1954. This regular feature continued, essentially uninterrupted, until 1985. The name of the column itself changed to Foreign News in the April 1979 issue (when the magazine underwent a logo and editorial revision). The column changed from monthly to bi-monthly in 1985 and quietly disappeared following the August issue of that year. Peter's engine reviews in MAN however continued until August 1988, sometimes with several full reviews per issue.

Peter's reviews remain a joy to study. He did not merely quote measurements and figures. Drawing on encyclopaedic knowledge, he considered design implications and contrasted these with other options, presenting all in clear, highly accessible prose. He is missed.

Cirrus Progress

The Cirrus is really starting to take shape now. Only one more major component to make, namely the cylinder head. After that, it only (only?!) needs a squillion fiddly little things, like pistons, rings, valves, guides, rockers, tappets, rocker perches, manifolds, etc, etc. However, rash commitments made to Model Engine Builder—surprisingly, made while totally sober—regarding completing the Morton M5, and building Bruce Satra's M1 and M2 variants will cause the poor old Cirrus to go back in its box and under the bench for the forseeable future. You should all get to read about these projects in the next three issues of Model Engine Builder Magazine. In the mean time, visit the Cirrus Construction Log to read about the crankshaft and cylinders.

While talking about Cirrii, back in the November 2002 Issue of Model Engine News, I mentioned Mr Ken-ichi Tsuzuki who had then just finished a beatuiful Weaver 1cc diesel using my plans and Roger Schroeder's casting kit. I chanced to revisit Kin-ichi's web site while testing the new navigation menu and discovered he is building the 1/6th Zimmerman Cirrus too, though he has redrawn the plans in metric, and is working without the aid of castings. Most of his site is in Japaneese, but pictures speak louder than words anyway. There are occasional captions, and my hat is truely off to him for the way he has modified the timing to be adjustable, and calibrated! Our progress is about the same at this time, although his engine will doubtless be running first. The site is well worth a visit; his workmanship is outstanding.

Hydra: No More Excuses!

Brian Perkins reports that he can no longer find sufficient excuses to delay final assembly of the Bristol Hydra he's been building. This will be a tedious and complicated task; first feeding parts into other parts in a sequence that does not prevent later assembly of a vital component, then getting everything that turns to do so freely, and without imposing undue distress to any of its neighbours. New Hydra assembly photos have been added to The Gallery for your enjoyment and admiration.

Incidentally, way back in 1996, an article by Brian describing his first foray into this insane hobby appeared in issue #51 of Strictly Internal Combustion magazine. The article was accompanied by cross section plans, but no detailed, dimensioned components. Now, almost 10 years later, this small omission is being corrected by a series in the Model Engineer, commencing with issue #4240, dated Feb 4-17, 2005. The engine is modelled on the Volkswagen flat 4 "boxer" (initially designed by Ferry Porsche prior to WW II). The text in part one is the same as that which began the article in SIC, with a couple of minor changes. But the detailed component drawings are new. These issues are only just now arriving in Australia. In England, the series is probably finished, so now would be the time to place orders for back issues.

RCS 400 Radial

This very attractive looking engine is being produced in the Czech Republic by ZDZ Modelmotor and marketed in the USA through RC Showcase. The Morton M5 is not exactly small, having a total displacement of 15cc. In comparison the red cylindered beast is a whopping 400cc!!! (it's modelling Jim, but not as we know it). There have been four door family compacts with not much more displacement under the hood. The engineering in this engine appears, from the photos, to be superb—and I appreciate and admire that. However its purpose and existance scare me witless. Some day there's going to be a big, nasty, and public accident involving a model powered by something this size, and all aeromodelling will suffer—even my beloved rubber band powered models (your average journo and politician being unable to differentiate between the two). Rant mode off. Back to business...

Yet Another Faux Twin

Unlike the faux Enya Twin that appeared here some time back, we believe this one will actually run. It's based on K&B components. One neat feature of the cylinder design for this engine is all the transfer porting is cast into the removable cylinder, and since it has a symetrical bolt pattern, the head/liner can be positioned anywhere. The two cases are joined with what appears to be a metallic epoxy compound, which experience coupled by the size of the goo blob, indicates will be strong enough to hold the cases together. The 1:1 gear coupling is quite practical and permits the engines to be timed however the builder wishes—most likely simultaneous firing. The only feature I'm not totally happy with is the radial mounting feet which seem to be screwed to the backplate castings, most probably with countersunk screws on the inside. The backplate castings are relatively thin and fragile. The center of mass is ahead of this point, so the castings will be highly stressed over a small area. Still, I've little doubt it will work and be a source of enjoyment to the unknown builder and his flying buddies (gotta be a "him"). Thanks to Ken Croft for sending the photograph.

Model Engine Builder Ships!

The shipping was the easy part (says MEB editor, Mike Rehmus), it was the arriving that was hard. Poor Mike consigned issue #1 to the tender care of the US Postal Service at the end of March. This was a very public event with Mike emailing charter subscribers to let them know, then ducking brickbats on numerous web groups as the weeks (yes, weeks) dragged by with no sign of #1 in US domestic mailboxes. But most seem to have it now. About the last place reached was one poor subscriber in California, not far from where it was published. The next day, my copy arrived in Australia. Go figure. So far, not a bad word has been heard, with Mike's layout receiving special acclaim—as is the Mills 1.3 feature by [ahem] yours truly (so far I've spotted so many typos in my own piece that I'm hiding under the table). There's at least two builders cutting metal on this already. The first of whom points out that the block of ally required for those hogging their own crankcase is 1-11/16" wide, not 1-9/16" as stated. How totally embarassing...

Sky Charger

This is a reproduction Sky Charger built by—wait for it—Les Stone (just how many engines have you built, Les?). The castings for this engine were produced and sold by erstwhile SIC editor/publisher, Robert Washburn. At the time, Bob was writing for Home Shop Machinist and it was the lack of editorial interest there on IC engines in general that led him to found SIC (if you don't yet have a full set of Strictly Internal Combustion, then you should, and time is running out—as are back issues with color covers). About 40 sets of castings went out when Bob's build article appeared in HSM. As far as is known, only two have been completed: Les' example seen here, and another by Ron Colona (who also built the 1/4 scale version of the Zimmerman Cirrus for SIC). More pictures of Les' Sky Charger appear on his tribute page in The Gallery.

New Books and Magazines This Month

While this is an old title, I felt it was appropriate to review it this month as the author is none other than Peter Chinn. This book is a collection, distillation, and expansion of material that Peter had contributed to Model Airplane News—quite reasonable when you understand the connection between that magazine and the publisher, "Air Age Inc" (read the banner at the top of the cover). In fact even after publication, some material written specifically for the book appeared as a three part series in MAN (see the Jul, Aug and Sep issues for 1987).

Model Four-Stroke Engines, PGF Chinn, Air Age Inc, 1986, ISBN 0-911295-04-6, cost a modest $13.95 when it first appeared. It is now out of print, but second hand copies are relatively easy to come by, that is if you are prepared to part with $275 for a like-new copy! (prices taken from Amazon's book sellers links—click on the book title to find them) As we might expect from the author, this is a well written book, lavishly illustrated with excellent, professional, black and white photographs and line drawings. Its 130 pages cover the history, design, development and operation of model four-stroke cycle engines. A 26 page appendix gives full size line drawings for popular four-strokes of the period. Single cylinder engines appear side on; multy-cylinder ones, front on. Basic technical details for each are included, but this section is now quite dated. The real value in the book is contained in the history, the various four-stroke design options and their relative merits. As a bonus, there's a chapter on the rotary combustion ("Wankel") engines that is worth the price of the whole book (the cover price, that is ).

The history section covers the pioneers like the Feeney and Leja, the Channel Island Special, and the V configuration, multy-cylinder four-stroke engines designed by David Stranger in 1097. It traces the failure (in the market) of the early four-strokes, and their re-emergence and rise in the latter part of the 1970's. Chapters that follow break down the engines by subsystem: cylinder head, valve gear, carburation, etc, giving all the options available, illustrating them with drawings and photographs of commercial and one-off prototypes. Sleeve and rotary valves receive very good coverage, as do the various configurations of multy-cylinder engines; in-line, opposed, radial, and V. The text is aimed at the savvy, but not highly technical reader (no math, no graphs), so you won't be designing an engine from this text. But at least you'll know what all the options are!

Engine Of The Month: ZOM!

This month's engine is a bit of a lame duck (the review itself, not the engine, I hasten to add). We know they are Spanish. We can see they are well made, with a certain 60's era look to them. Other evidence indicates that the ZOM line was diverse: diesel, glow, R/C and conventional carburation, but that's about it. If any reader can shed some light on the engine and its provenance, we'd sure be pleased to hear about it.
 

Tech Tip of the Month (1): Multy-throw Cranks

You could say that anyone making a multy-throw whatzit is obviously a crank, but then I'd have to plead guilty ("plead" I hear someone ask?) The Cirrus crank came out nicely enough—not perfect, but then I've yet to make the "perfect" anything. Manufacture seemed to involve some techniques that are worth while documenting in a degree of detail for others, so this has been done. I was sort of reluctant to do this, as anyone attempting such a project is most unlikely to need words from me, but some of the techniques have wider applicability, so this month's first tech tip covers one way in which the Cirrus crank, and multy-throw cranks in general can be approached.

Tech Tip of the Month (2): How to Knurl Prop Drivers

There are a number of ways to produce prop driver knurls. For some reason, engine builders starting out seem to be mystified and afraid of this task, but it's really easy. I thought I'd described the process to death in all my construction projects, but Roger Schroeder pointed out that the site-search utility says otherwise. So our second tip for the month, somewhat belatedly, describes some ways you might go about it. The photos come from all over the web site, but the words are new.

Cookie Cutters

Making gaskets is yet another activity that many engine builders view as an unavoidable chore rather than a pleasure (for a supposedly enjoyable pastime, there sure seems to be a lot of thse kind of jobs, aren't there?) Eric Offen showed us how to make a punch in the March issue of Model Engine News. Another way is to use a compass-like circle cutter. You can buy little plastic circle cutters all over the place, but Bert Strigler felt he could do better, cheaper—and did! Here's how he described the prototype to the rest of the Motor Boys:

Roger Schroeder very quickly replicated Bert's tool and found it worked precisely as advertised. Can you pick the material used by Roger for the test gasket seen here? It's a playing card; the type with a plasticised coating. This tip came from from our friend, George Aldrich way back in the early days of our group. I think we've all used it now. The other choice, for thinner gaskets, is plain brown paper—they type you can get your groceries packed in (I miss the "paper or plastic" question. Down here it's pure plastic, causing our beloved government to roll out Yet More Legislation because of the plastic bag problem).

Roger liked his cutter so much, he has gifted it with a wooden handle made from some form of endangered South American flora. We all agree that having gone that far, he must now complete the job and make the fitted wooden case, with dovetail corners, felt lining, and polished brass hinges. So far he's resisting...

New Hobby Shop in Beenleigh

I mention this one only because Beenleigh featured prominantly in my childhood, as I was dragged kicking and screaming to the Gold Coast every weekend in the early 50's. At that time, the two hour trip by single carriageway went through the sleepy hamlet of Beenleigh, the the even smaller one of Yatla (at least they had a fameous fish 'n chip and pie shop). Today the six lane freeway has bypassed all such bucolic places, but David Robertson has launched a new venture based on a "I will not be undersold" promise. Kickoff is planned for June 2005. You can visit his wesite at http://www.cricketbats.com.au, but there does not seem to be much model stuff there yet.