Model Engine News: June 2005

   Vale: OFW Fisher
   New Wright Based Engines
   Two-Stroke Radials
   Anodizing Update
   Minor Page Updates
   The Camms
   The DR5 Radial
   A New Tribute Page
   Shop Activity
   Cheap and Cheerful Twin

   Editorial
   New Books and Magazines This Month
   Engine Of The Month: Two-Stroke Radials
   Tech Tip of the Month: Drivers Again
   Standard Stuff

Editorial

On returning from working in the US, and joining DSTC in 1998, I took advantage of the company's policy of providing home page space to staff, allowing them to publish anything—within reason—related to their current research or not. My initial page was a short treatise on experiments in back-yard anodizing. An ulterior motive was to write the pages in raw HTML (Hypertext Markup Language) as a way of gaining a low-level, in-depth practical knowledge of the technology, as that was peripheral to some of my research work.

The site gradually expanded, greatly enhanced by pictures from Bert Streigler, Ken Croft (both very accomplished photographers), and many others. Information was added about the Motor Boys International group as our plans to produce a book of our plans developed. A front page hit-counter was added in September 1999 and has functioned more or less uninterrupted ever since (though there have been some months of outage due to fun and games with the counter host). Additions were made as and when I felt like it, making the whole mess more of a personal journal than any kind of resource for model engine builders.

After about a year of this, and following some emails from the growing readership base, a history page was added that got updated periodically as a way of letting people know what had changed lately. At that time (circa late 1999), the front page (click here to see the old front page) was and rather crude and got changed at whim. Worse, it did not follow the naming convention for a web site entry page.

This was corrected and the page replaced by a new front page that changed every now and then. This provided links to the main items, plus the "What's New?" page. The What's New page in turn contained links to what had been added or modified recently. Predictably, this did not always get updated and material was being lost, misplaced, folded, stapled, and probably mutilated. Worse, as the page was changing, search engines links to it were being invalidated, so a single, fixed front page was introduced. This was still far from ideal but real change generally requires a trigger.

The trigger came in 2002. This was Bob Washburn's decision to retire again and cease publishing Strictly IC. This left a void for me, and I was sure, for many other SIC subscribers as well. Combine this with the unmaintainable mess that my web site had become and it was an easy decision to change the format to be an on-line news letter with items for model engine builders, collectors, historians, and others who share my addiction and affection for the dirty, oily, smelly, noisy things. And as I was not charging for it, it could contain anything I liked, at any quality I chose to dish up!

That decision was made in June 2002, with the first actual result appearing as the July 2002 page—making June the anniversary, three years ago. The new format also permitted me to introduce better targeted metadata into the pages so that searches using engines like Google and others would return good links to my pages for simple queries (an aspect of my day-time research work). The exact form of that page no longer exists as all pages were revised last year to use a layout set by cascading style sheets (CSS)—more overflow from the day job. However the text is the same. I chose to make the foolish commitment to publish monthly, on or just before the first of the new month, knowing I've always responded well to deadlines. So far, each one has been met.

That brings us to today. The site is still far from perfect, but the revision to the navigation menu detailed last month should have improved matters (at least no one has written to say otherwise). At this time, you can perhaps look forward to another year of these pages before we close the doors and turn off the servers on June 30, 2006.

Sometime back, I floated the idea of burning all these pages to CD and making them available for a nominal sum. Because of the increased use of scripting to power things like the Engine Finder, the Site Search Facility, and the Index of Model Engine Reviews, this project has slowed to a crawl. But I've not abandoned the idea—irreverently dubbed the MEN Only CD—and still intend to make this resource available before the end.

My objectives for the CD are that is should function just like this web site, with all the dynamic features fully functional. It should also be environment neutral; able to run on either a Unix (Linux) system, or a Windoze box, with very little effort on the part of the user during setup. It now appears that Yet Another Language Ron Has Been Ignoring, namely PHP, may provide the bridge that makes this possible. As I've said many times before, stay tuned!

Vale: OFW 'Peter' Fisher

Again, I'm sorry to have to begin this column by announcing the passing on April 13, 2005, of another aeromodelling pioneer: Ocean Francis William Fisher, or 'Peter' to those who knew him. OFW Fisher will probably be more familiar to those of us who grew up on a diet of Aeromodeller magazine through his company, Performance Kits. To me, all his designs had a distinctive flavour that identified their designer. Take the asymmetric free-flight wing in the picture here (taken from the rear cover of his book, Collector's Guide to Model Aero Engines, reviewed appropriately here this month). I think it is the cockpit treatment; the triangular, raked framing. It just screams "Fisher" (yes, I know the wing has no cockpit, but the Performance Kits logo with the lightning bolt in the circle is a dead give-away, isn't it?!) Motor Boy David Owen met and stayed with Peter on one visit to the UK, recalling a most pleasant bloke and a "freezing bloody night" spent sleeping in his clothes at the rather bleak Onchan Castle. This seems to be a year for pioneers departing at a rapid rate; as Bert Streigler observed, tempus fugit.

New Wright Based Engines

Way back 1991, SIC began a series for the construction of a quarter-scale replica of the Wright J-50 Whirlwind—the nine cylinder radial chosen by Charles Lindburg for his historic trans-Atlantic flight. This engine was designed by Karl-Eric Olsyrd for a quarter scale model of the Spirit of St Louis. Investment castings for the engine were available from Carl Eric Carlsson in Sweden. Years have passed, but neither of these gentlemen have been standing still. Recently, KEO Engines added a number of engines to their web site based on the Wright cylinder. Click on the thumb-nail pic to be taken to the KEO Website where you'll find more details of the single, opposed twin, and flat-four models. The bore of the cylinder is 26mm (1.024"), so these are not small engines, but trust me, in a way that simplifies things (having just spent a month making the Morton M5 based "M1" with 0.150" diameter roller tappets). Right now, I'm trying to resist buying yet another set of twin castings—just not very hard though!

Two-Stroke Radials

This is a topic that surfaces from time to time: is it possible to build a two-stroke radial configuration engine, and would it be simpler than an equivalent four-stroke? Yet again, the answer—in no particular order—is yes, no and maybe. Actually, this has been done a number of times already, with some offered as relatively small production run "commercial" products. These are described as this months Engine of the Month, but it's also worth mentioning the only full-size two-stroke (or cycle) radial that I'm aware of. That is the Murray-Ajax shown here in line-drawing form taken from Aerophile for 1941.

It's a little difficult to see how the designers handled the detail, but it appears that the engine was piston ported, with the transfer fed from a belt that was pressurized by a separate blower. How the exhaust was separated is not clear, but note the twin deflectors on the piston crown that indicate transfer was on the sides of the cylinder, with exhaust fore and aft. It's worth mentioning that the Gnome Monosupape, while using piston timed transfer ports like a two-stroke, was in fact a four-stroke. Even though the piston uncovered the transfer ports at the bottom of each stroke, induction at BDC of the power stroke was limited by relatively higher pressure in the cylinder at that time.

But back to the Murray-Ajax. The text states that the air/fuel mix was fed from the crankcase which was pressurized by a vane-type "supercharger"; surprisingly similar to the Berger Radial model two-stroke radial described briefly this month. Notice that two configurations are illustrated: one with six cylinders; the other with eight—both even numbers of cylinders (like the Bristol Hydra). This poses no design problems as all will fire in sequence during a single revolution. This single page constitutes all that I can find on the engine. If anyone has more data, or an actual photograph, I'd love to hear about it.

Anodizing Update

In the April 2005 issue of Model Engine News, I mentioned finally taking the plunge and buying some for-real anodizing dyes and other chemicals from Ron Newman. The order included a treatise by Ron titled A Practical Guide to Anodizing Aluminium at Home. Ron's website shows some very attractive results, so I was curious to see if his basic process differed greatly from mine. The answer is, as always, yes and no. The photo here shows the results of simply using a new cleaner, and "sealer". The basic anodizing setup has not been changed. Previously, I'd used steam to close in the color. This has the undesirable effect of also leaching out some of the color! The new process uses a nickel acetate sealer that does a significantly better job.

The kit also contains eight different color dyes. The reds in the picture above are a combination of my old "Dylon" brand (the more crimson ones), and the new dye (the more scarlet ones). The green is totally new—being a color I've never had success with before. The success is so profound now that I wish I'd pulled the parts out earlier—they're almost too green! The little tubs of dye are sufficient to make a two gallon vat, allowing quite large jobs to be tackled. I use small pickle jars so I can easily microwave them up to around 80 degrees C (180 degrees F).

The Practical Guide... restates a lot of the information that Ron Newman provides on his web site for free. The additional material would be of value to someone planning on going a bit further than simply tarting up some bits for himself—more in the lines of a part-time business catering to bike customizers and the like. However, all the basic steps are well covered, as is the true secret, which, as I'd discovered by trial and lots of error, is in the surface preparation and finish prior to anodizing. The guide describes several mechanical shakers that can be used to automatically polish away machining marks etc. This provides the reflective luster that can make some anodizing jobs look so great. It also contains tips on setting up tanks of various sizes, how to aeriate them, cool them, heat them, and trouble-shoot problems. I learnt a few things. Someone just starting out though would save themselves a lot of experimantation and wasted time by following the processes described. All-in-all, recommended; expect to see some truly bizare colored anodizing emerging from my shop in the years to come.

Minor Page Updates

As a result of the anodizing experiments, some minor additions have been made to the pages linked below (the changes are mostly appended to the bottom of the page, in case you are wondering). The Westbury Index page has a new photograph showing ETW with Gems Suzor (look him up with Find) at the 1950 Model Engineering Exhibition. The ETW engine list has had some corrections made to the bore, stroke and displacement figures of certain engines, and now includes values, previously missing, for the 1831 locomotive engine. These fixes are thanks to the efforts of one of our eagle-eyed readers. And for no particular reason, the heading photo here shows the Big Green Experiment on a rather sad DC Spitfire. The green is so green, it's almost black! If you look hard you'll see the accident I had with a milling cutter while touching up the spanner flats on the head—without tightening the mill vise first!

   1958 Taipan 1.5
   1962 Taipan 1.5
   ETW Index Page
   Westbury's Engines
   Zom

There's also an update to the Prop-driver Knurling How-To page, but I'm making that substitute for this month's Tech-Tip , and the Links Page has had new links added to the KEO Engine site and the brand-new Vernal Engineering site (home of the Morton M5 Radial).

The Camms

Not long ago, a hot topic in research was "The Great Interconnectedness of Everything" (think "three degrees of separation", etc). It even hit on us here in Information Technology research. While researching background on the Newness publications for the Deller spark engine page, the name "FJ Camm" came up prominantly as the editor of the magazine in which the Deller plans appeared, as well as many other publications for the mechanically-minded of yore. Of course the name "Camm" is more closely identified with one Sir Sydney Camm, designer of the Hawker Hurrican, Hunter and the VTOL P.1127, amongst others (and a critic of Roy Fedden's work, further supporting the theory...)

Correspondence with a reader in England over the past month discloses that FJ Camm was younger brother to Sir Sydney. And as if that were not enough, Fisher's book reviewed here this month observes in the Foreword that one FJ Camm developed a three cylinder flash-steam power plant for model aircraft weighing 7/8 lb (398 gm) all up and developing 0.2 BHP at 1500 RPM. This reference in Fisher quickly had me reaching for FJ Camm's 1949 Model Aeroplane Handbook, and sure enough—there was a whole chapter devoted to this very same flash steam power plant, with enough detail for an experienced model engineer to build one. Now tell me everything is not connected!

New Books and Magazines This Month

Again, it seemed appropriate to review a book that is hardly new, and out of print to boot, namely [The] Collector's Guide to Model Aero Engines, by O.F.W. 'Peter' Fisher, Argus Books Ltd, Herts, England, 1977, ISBN 0 85242 492 2. A quick search of the 'usual suspects' on the web failed to turn up any copies currently on sale, but regestering a request with one of the on-line services like Advanced Book Exchange, or Tee's Booksearch may yield results down the track.

Back to the book. This 132 page volume is hardbound, in a 6" x 8-1/2" format similar to the beloved "Aeromodeller Annuals" of old (not surprising given that they share the same publisher). What is a bit unusual about it is the layout—which I'll admit, takes a bit of getting used to, but once understood, works quite well. There are 18 chapters covering the various types of engines: compressed air, petrol, 'slag', diesel, glow, etc. Even pulse jets, "Jetex", and electric get their own chapters! Others cover ancillory equipment like props, timers, tanks, operation, etc. A brief introduction covers the history of model engines, which, while starting with a paragraph devoted to Langley's model "Aerodrome" of 1896, then takes a very British slant on developments. However, the other chapters present a more globally balanced view of the types described. While the depth of coverage is relatively shallow, the bredth is high, placing this book is on my "must consult" list whenever I have to research a particular type, or model. Seldom does it fail to yield some information, or provide a lead of where to look next.

The "inaccessable" criticism frequently levelled at the book comes from the decision to collect most of the photographs together at the rear, with occasional shots positioned with the text that refers to them. This is not so bad as it first seems. Each shot is numbered. The text contains bracketed references to the relevant figure number, and two separate indexes ensure all the dots can be connected. The first index (at the front of the book) lists the photographs by figure number, identifying the engine depicted. This is followed by a page reference for accompanying text if appropriate, and the serial number of the engine in question, where available. At the back of the book, a more conventional index lists the page numbers and Figure numbers for all the engines mentioned in alphabetical order. Page number references are in normal print; figure numbers are presented in itallics (but you'll have to use the front index to locate the page number for the figure!) Once all this is understood, the book becomes quite navigable—if a mite unconventional.

There are 248 engines illustrated, some quite artfully. For example, figure 46, the Morton M5 is posed sitting on it's mount like a LEM ready for lift-off, with a rather large piece of very live python curled possessively around it. In figure 150, the Speed Demon is almost unrecognizable, being dwarfed by a distinctly unamused Pursian cat shoved into an open drawer next to it (I love that picture ). A list of the engine owners is given in the Acknowledgements, with some quite notable persons mentioned (Clanford being notable by his absense). Finally and appropriately, a number of engines are fitted to Performance Kits airframes, all of which bear the unmistakable trademarks of OFW Fisher's designs—difficult to define, but easy to pick. The book is a good reference to own. If you can't locate one for sale, try your public library.

The DR5 Two-Stroke Radial

During May, I received a 'mail and website URL from Yiannis Mantheakis who has been developing a prototype five cylinder, two-stroke radial based on Norvel cylinders (pictured here). The engine is reed valve and so will run in either direction. You can watch video of the engine in operation at the DR5 website (the link is a bit hard to find; look in the top area of the column on the right). Yiannis reports that a Cox-based model produced an exhaust note that exceeded the threshold of pain.

Ultimately, he plans commercial production using cylinders of his own design. In a 'mail to me, Yiannis says his engine is not geared and has a common crankcase charging all cylinders. Induction is via a reed valve assembly. The video on his web site shows the engine starting first flip (more like a karate chop, actually). So far, internal details have, understandably, not been disclosed.

Engine Of The Month: Two-Stroke Radials

The DR5 Radial and the Murray-Ajax mentioned above have at last prompted me to action on a subject I've been meaning to insult with my ignorance for some time: the model two-stroke radial. This is not so much an engine review as a "technology" review, examining some schemes that have been tried over the years, and illustrating them with examples (photographs of photographs sadly). But next month, with luck, we'll have an in-depth review of an actual commercial (and rare!) two-stroke radial. 'Til then, click the link for info on ways in which such beasts can be made to work.

A New Tribute Page

Where's Les Stone's picture for the month, you ask? Well, Les 'mailed me with a great suggestion. Roger Schroeder has been contributing to this hobby for forty years this month. That's forty, FORTY, 40 years! And that just begs for some recognition, so the Engine Gallery has a brand new page: A Tribute To Roger J Schroeder. From all of us, thanks Roger...

Shop Activity

Shop activity this month has been intense, with the building and testing of a Morton M1 from Bruce Satra's castings. I'm not spilling any secrets by disclosing that this will appear in Issue #3 of Model Engine Builder, as Mike Rehmus has announced this on a number of web forums. Most of the effort in building an M1 is in making the jigs and tooling. Fortunately I had a lot of this ready as a result of the stalled Morton M5 project. One reason I lept at the chance to build the M1 was the thought that the M5 cylinders could be debugged one at a time in the M1, thus eliminating five areas of uncertainty from the mix when it comes time to start the M5. The head in the M5 uses Bruce's new "high Compression" revision to the castings, giving about 9.5:1 (Geometric C/R) for use with either glow-plug or spark ignition.

In the meantime, the Mk I Cirrus has temporarily gone back under the bench, but should come out again before the year is gone.

Tech Tip of the Month: Drivers Again

With everything else that we have here, and the burst of activity required to complete a four-stroke single in three weeks, our tech-tip for the month is a bit light: merely an update to the prop driver knurling piece from last month. It covers a way to produce a neat looking knurl on a large diameter driver using a trick from the venerable old Frog 500, a subject incidently that deserves a full review, and will get one Real Soon Now..

Cheap and Cheerful Twin

Joe Webster, designer of the Son-of-EZE, sent some pics late last month of a very simple twin he'd made from Cox RTF engines to an idea from Andrew Coholic. The result—a simultaneous firing twin—runs just fine, is well balanced and easy to tune. We can't have that, can we?   I suggested Joe adjust the mesh to make it an alternate firing twin; worse balance, but two power strokes per rev verses one.

To my surprise, Joe dutifully tried this and reports that vibration was noticably up, and the engines became very difficult to tune. In fact, he could not really find the "sweet spot" and the RPM was down by about 500. However, the exhaust note from tha alternate firing order was, to quote Joe, "wickedly cool, like a buzz-saw". Now all Joe has to do is add another Cox with all set at 120 degree intervals and he qualifies for a merit achievement badge in the Tinkerer Class of two-stroke radial builders. Good effort, Joe!