July again, already? (Happy 4th, by the way) Where did it go? I've had an unusually busy month work-wise. Add to that putting together the article on building the Morton M1 for Model Engine Builder magazine, and it adds up to a rather light News page in comparison the monsters of recent months. Still, I hope you all get some enjoyment and maybe some useful information from it.
Speaking of MEB, Mike Rehmus tells me that issue #2 is at the printer and may even be being dispatched, if you are reading this page at the start of July. If it's any consolation, MEB#2 will be a monster at about the equivalent of 90 pages after you take the folded drawings into account, as it includes Robert Sigler's CAD redraw of the Morton M5. Bruce Satra has declared these to be THE Definitive Plans. All others should now be torn up and burnt. Certainly don't get suckered into bidding on eBay for photocopies (there must be a special circle in hell for those who put these up for auction—a circle where one must stand bare-footed in swarf up to your thighs, endlessly bending M5 inlet pipes, none of which will ever quite fit).
At least no pioneers have died the past month (knock on wood, and as far as I'm aware). Following on from last month's theme, this issue of Model Engine News contains no less than three two-stroke "radial" engines—and I think that will just about close the book on the subject. We also review two book this month, both of which are actually still in print for a change. Incidentally, the little problem that excluded the and icons on the left-hand menu bar from being part of the active hyper-link is now solved (and I'm far too embarrassed to say how simple the solution was). No idea what next month will have, but I'm sure something will emerge...
New Burford Accessory
Remember the PB03 diesel from Master Engine Maker Peter Burford, son of Mr Taipan himself, Gordon Burford? (and that must be a new record for the most hyperlinks in a single sentence ). When I visited Peter just over a year ago to take up his kind offer of a shop-tour, we chatted over coffee and cookies about the possibility of an R/C carburetor for the tiny .03 cuin (0.5cc) diesel. Well, out of the blue, a parcel arrived this past month containing one of the first production models to emerge following his extensive and comprehensive development program.
This little jewel (less than 1" across, including the needle valve), has an injection molded body, with a steel barrel. The needle appears to be the same stepped, finely ground unit used in the standard engine. Peter certainly knows injection molding inside out (that being his main source of income—you don't get rich making model engines). I know where the die parting lines must be on that carb, but the finished product shows no sign of them! That requires precision, and although Peter says his engine is full of compromises, I still think it is one of the finest, high quality, no-compromise products I've ever seen. If you have a pb03, or would like more information, email Peter at [email protected] to get more info on the carb.
Funck Two-Stroke Rotary
Ahhh, the joys of advancing age and failing memory, like all those books I can read again for the first time. When putting together the Technology Review for Two-Stroke Radials last month, I was aware of a real odd-ball called the Funck after its designer, but failed to make the connection. Although the engine is a rotary (ie, the crankshaft is stationary while the crankcase, cylinders and attached prop spin around it), not a radial, it qualifies under the definition adopted and should have been mentioned.
In fact, it was a reader some years back who alerted me to the #44 Model Engineer book by Caunter precisely because of the detailed description it contained of the Funck. I had been trying to obtain an original off and on ever since when a periodic search disclosed the TEE reprint mentioned this month. The little booklet may be short on detail elsewhere, but Caunter goes into great detail on this strange engine. It approaches the problem of pumping and scavenging very differently. Each cylinder has its own separate charging cylinder, so there are two banks of cylinders and pistons. The charging cylinders lead the power pistons so they are reaching TDC as the power pistons approach BDC. This provides the pumping action that provides transfer and assists scavenging, the same as the crankcase volume does in a conventional single cylinder two-stroke. Of course, we've nearly doubled the weight, friction, and complexity, but no inventor ever let little draw-backs like that stop them!
Another rather unique concept tried by Funck was the "flame-tubes" that connected one cylinder to the next as seen in this diagram. His idea was that as each cylinder must fire in sequence (not alternate odds and evens like a four-stroke radial), the hot exhaust gas from the cylinder that had just fired could be used at just the right time to start the combustion cycle of the next cylinder. Caunter notes that Funck later abandoned this idea and relied simply on the conventional spark plugs in the "junk" heads. These were necessary as the exhaust exits around the top of the cylinder, the ports being uncovered by a sleeve attached to the power pistons. Now we are talking serious additional friction! Still, a most interesting concept for students of such things—to which I must plead: incredibly guilty.
Geared Cox Triple
Isn't it amazing how things happen in threes? Last month Model Engine News featured two-stroke radial technology. The Hiness Radial was already scheduled for the microscope this month, then along comes word of a Cox based, geared star-configuration engine made by an Italian builder. It uses the inexpensive RTF engines that seem to be so plentiful at the moment. It's difficult to tell, but I think the gearing has a slight reduction. The timing is not known either, although 120 degree spacing would seem likely.
Nothing by moi (this has been a very busy month on other things), but here are my Cirrus cylinders are returned by ozzie Motor Boy, David Owen (originator of the DCO Contra-piston Fitting Method). Dave has kindly blacked them for me and done a job on them that's so good I had to carry them around the house with me for hours to assist the admiration process. Someday I must get him to describe the treatment he used in detail for us. The next job on the Cirrus will be the cylinder head, but as actual progress is taking place on the Morton M5 radials, this will have to wait a bit.
New Books and Magazines This Month
The first of our two new books for the month is a reprint from TEE publishing: Model Petrol Engines Their Design and Construction by CF Caunter, ISBN 0 905100 69 7. This little booklet was first published as Number 44 in the Model Engineer Series by Percival Marshall (England) in 1930. TEE's reprint is from a good condition example with all photographs and illustrations as clear as can be expected, given the process involved. It contains 72 pages in a 4-3/4" x 7" format; probably close to the original size. In the Preface, CFC states his publication is the first, to his knowledge, to deal exclusively with Model Petrol Engines, and its purpose is to induce model makers to come forward with their new designs, improvements, and ideas. In nine chapters he covers the technology of the time, drawing on examples designed by Westbury, Stuart (more famous for their steam engines), and others. Although some cross-section general arrangements are shown, there are no dimensioned drawings and with one notable exception, the book might be considered to be of historical, academic interest only.
The second book is a vastly different kettle of fish: Model Engine Mechanics, by Gordon Cornell, self-published, Coventry, England, 2005 (no ISBN, and available only from the Author). Readers who subscribed to the old Model Engine World will be familiar with Gordon's highly informative and technical articles. In his book, Gordon expands on these articles and adds extensive new material on theory, design, construction and everything else you can think of related to model two-stroke engines. Drawing on 60 years of experience in the field, with experience as engine designer at FROG and ED Ltd, Gordon takes us from the early English side-port diesels to modern high-performance, Schnuerle ported glow engines. He illustrates the practical side of the book with examples from his "Dynamic" series of high performance engines which have been available as limited production engines for many years.
The book contains 156 A4 pages, printed using color ink-jet technology, and spiral bound. The chapters cover all aspects of design and equally important, evaluation. Theoretical aspects are given thorough treatment with associated formulae, tables and graphs. An optional CD may be purchased with the book to assist with analysis and design of model internal combustion engines (hence the name ICE). The program allows users to model and evaluate design parameters for single cylinder two-stroke engines using crankcase pumping with both piston and rotary inlet porting. American readers will be pleased to know that ICE operates on Imperial units—although the difference between Imperial and US gallons should probably be kept in mind.
The illustrations include photographs (color and black & white) plus color 3D models. The construction chapters contain extensive details on the jigs and fixtures Gordon has used in his limited production runs. His workshop is very modest: a Myford Super 7B lathe, fitted with shop made fixtures and a tool-post grinder of his own design. In other words, the sort of equipment that might be found in the typical home shop. Recently, he has added a small CNC mill to produce 'bar-stock' engines rather than the sand and die cast cases used on earlier Dynamic engines.
This is a most comprehensive book. As it arrived just before 'publication time', I have not had time to do more than skim the surface of its contents. My initial feeling are that this is the book I have been wishing someone would write. As mentioned, it is available only from the author. You may email him at Gordon Cornell [[email protected]], or phone on +44 24 76503038. His postal address is:
Mr Gordon Cornell
19 The Earls Croft
Coventry CV3 5ES
Overseas customers will have to arrange a bank check or cash; Gordon is not equipped to take credit cards, nor PayPal. Let him know that you learnt about his book here—it may help persuade him of the value of on-line services .
Engine Of The Month: Hiness Two-Stroke Radial
As promised last month, this month we take a close look at a rare and unusual engine: the Hiness three cylinder, two-stroke radial. The engine pictured is from the collection of David Owen who very kindly pulled it down completely for the review. This, the Funck Two-Stroke Rotary and Geared Cox Triple in this issue, last month's Engine of the Month and the review of Two-Stroke Radial Technology from last month should just about close the book on the subject.
The Allan Roberts Collection
For a small place, New Zealand certainly manages to punch above it's weight in a lot of categories. Back in the March 2005 issue of Model Engine News, we saw photos of Murray Lane's twin-row Gnome rotary taking shape. Murray had mentioned another Kiwi engine builder to me in emails; one Allan Roberts, apparently a builder of rather prolific proportions. Murray promised to send a CD of photos—there being so much scope to cover, electronic transmission was not practical. The CD arrived just too late for our "first" July issue, but I've snuck it in late (July 6th) knowing that the majority of the monthly 9,000 hits come from the USA, and hoping that the Independence Day vacation may delay first visits to this page (hence the good old European "bis" tag on the page title—now you know). Besides, I can always tell folk about it again next month and get double the return . A permanent link to the Allan Roberts page has been added to the People sub-menu on the left navigation bar. Still not sure if I like this part of the site design. Who's in? Who's out? Who's a "pioneer"? Who's on second? (no, Watts' on second). Agghh, t'ell with it...
New Engine in the Finder
And finally, because I'm feeling guilty, a new engine has been added to the Engine Finder: The Italian Osam 5cc diesel. The Osam was the predecessor to the more well known Super Tigre marque. It is a bit innovative in that the designer allowed for front rotary, rear-rotary, or piston-ported induction off the same basic crankcase casting. When not being used for induction, the rear facing hole in the case was either blanked off, or fitted with a cut-out device, as seen here. Check out the finder for this and another example of the engine (thanks to Bert Streigler and Ken Croft for the pictures).