A Happy and Prosperous 2012 to all readers of this twisted mess of a web site. As of January 2012, the Model Engine News domain includes 1,021 separate HTML pages, 17,541 jpg images, and 296 other things in 217 directories, using a bewildering and illogical assortment of styles, plus uncounted browser defeating html coding errors, not to mention spelling mistakes and typos. I'd fix it, but the job's too hard and life's too short, so there. The picture shows what Australians now tend to enjoy at this time of year in preference to all that hot, roasted stuff the Northern Hemisphere folk traditionally feast on. Incidentally, the things in the upper left that look like Trilobites are called "Morton Bay Bugs" and I take my hat off to the first person who thought that eating one would be a good idea. I'm glad he did though, they're sort of like a giant prawn (or shrimp, if Paul Hogan has distorted your world-view), which need a cleaver to get into, but are sweeter, and lots cheaper than lobster.
As has been my tradition now for several years, I'm making no New Year's Resolutions, except to avoid champagne. I'd like to say that 2012 and retirement will see me finish a number of stalled projects and start some of those kits and unfinished models that reside under the bench and in various closets around the house. But if I did, then didn't, I'd have to deal with all of the attendant feelings of guilt and failed obligation, so best to just say that I intend to have fun in 2012 and hope you do too. First off the rank will be a total bathroom renovation with a giant hot tub and spa (yes, Ruthie's idea, but I didn't argue very strongly). Easy one that, since I won't have to do more work than write the cheque for the final bill.
Poor old Adrian Duncan has spent a rather miserable time of it in the past few weeks, being down with various strains of virus (the biological kind) which have kept him and Nora low. To ease his load, I've taken over the Engine of the Month duty for this issue. Adrian's on the mend and with luck and a following wind, we'll have Chapter 3 of the Fuji Story ready in February. I think you'll enjoy this month's assortment though...
The First Commercial Schnuerle Port
Some strongly believe that the "first production Schnuerle port" prize should go to Super Tigre for their 1960 "Jubilee" G.20/15 with the patented transfer system. Yes, the piston is flat-topped, and yes, the angled transfers (45° upwards, and converging slightly) achieve loop flow, but the transfer ports are opposite the exhaust port, not positioned each side of it to direct the flow rearwards and upwards in the prescribed Schnuerle manner. Neither does Chinn call it Schnuerle porting in his reviews of the engine (Model Aircraft, Oct and Nov 1960, and Sep, 1961). As another point of interest, in describing the first G.20/15 "Jubilee", Peter Chinn noted that transfer and exhaust opened simultaneously at 65° BBDC. The well-used G.20/15 (diesel) liner pictured here has 0.080" between port tops, suggesting the idea must not have been a great one and did not last.
After some research and argument, I believe we can now definitively answer the question as to which model engine manufacturer was first with a mass-market, Schnuerle ported motor. The answer is (probably), the Hirtenberger (HP) .61, circa 1968. I say "probably" because it could be argued that the honor more rightly belongs to the HP .15 diesel of 1967, but I'm awarding the prize to the .61 on the grounds that the brilliant little Bugl designed .15 did not appear in sufficient volume to qualify as a main-stream, commercial product. That said, in his review of the HP .61, while Chinn does say that it is Schnuerle ported, he does not say it's the "first" to use this type of porting. Perhaps he felt Bill Wisniewski and his 1963 K&B "Wart"—which was never a production engine—made the whole thing moot. Click the thumbnail, or the HP .61 link above for a read of Peter Chinn's MAN, Jan 1969 review of the engine.
Regarding the on-going application of Schnuerle porting and the invention of the "Boost" port, some additional information arrived at the start of December which adds more to the where, when, and whom of the subject as applied to racing bike engines, which provided the technology copied by model engine makers. All this will, I hope, let me produce a reasonably complete picture (in words) for next month.
Some time ago, we posted a Tribute page dedicated to EC "Ted" Martin, designer of the Amco PB and BB engines, the MAN .19, and some rather powerful full-size racing engines. In this, we mentioned the garden railway which Ted built after his return to England. A kind reader has sent some photos of this layout which put a whole new perspective on the concept. Some photos and additional text about them have been added towards the end of the Martin Tribute page. Be sure to have a look; you will be amazed.
During the 1950's, John Oliver produced some specials based on his Oliver Tiger cylinder including a number of "double-ended" engines for tether cars, and some in-line alternate firing twins based on the 2.5cc and 1.5cc "Cub" cylinders. The illustration here (from the 1959 Aeromodeller Annual) shows a 5cc Oliver twin (others are shown in Mike Clanford's A-Z), page 152.
So what more natural than CS, the maker of the modern day Oliver replicas of variable quality, should do the same. The photo here shows the CS Oliver Twin recently obtained by Adrian Duncan from Carlson Imports. In answer to the question of where did they get the engine to copy, I think it's safe to say they didn't—this is all their own work. Adrian has yet to pull it down to see what makes it tick, but expect one of his thorough write-ups on the CS Ollie Twin in the months to come.
Incidentally, our old "friend", John Goodall of Barton Model Products (UK), produced what is reputed to be a very good an informative book on the Oliver engines. Originally produced as a limited edition hard-back, a soft cover is now available from BMP for £20.00, plus postage. If you order, tell him Ron at Model Engine News sent 'ya, that'll surprise him !
Quite some time back, Adrian Duncan provided us with a review of the early British BMP 3.5cc diesel. Since then, more information about the BMP has come to light, including a great deal relating to the engine's designer. Consequently, Adrian decided that a complete rewrite of the BMP page was required and that the previous page should be totally purged as an embarrassment. This has been done, so click the thumbnail, or follow this link to the New BMP page where, amongst other things, you'll learn the linkage between BMP the engine, and BMP, the modern-day engine broker.
As a start to the New Year, it feels appropriate to add some new entries to the Engine Gallery. The new entries are an ambitious Wankel Rotary built by Warren Vickery (UK), and a delightful Mills 1.3 Mk I built by Jim Frew (UK) from my plans which appeared in Volume 1, Issue 1 of Model Engine Builder magazine (back issues still available). Both engine perform well and are a tribute to their builders.
New Books and Magazines This Month
The Great Schnuerle Debate in these pages over the last few months has certainly changed what I know, and what I thought I knew about the subject. One of the most valuable insights on the origin of the "Boost" port was provided by Australian Model Engine Maestro, Steve Rothwell, builder of the fabulous R250 (and if you don't have one, you are too late, Steve has ended production). In his email, Steve asked if I knew of a book titled Stealing Speed, and generously offered to loan me his copy. Knowing the dangers of lending and borowing, a quick check showed that the book was readily available from Amazon and others, so even though motorcycle racing has never interested me greatly, I ordered a copy of my own and thanked Steve for the tip. I'm now ever so glad that I made this little purchase.
In 208 pages (soft bound in my case), with fourteen pages of black and white photos and illustrations, Stealing Speed, by Mat Oxley, Haynes Publishing, UK, 2010, ISBN 9781844259755, tells how the two-stroke was essentially reinvented as a high power engine by East German engineer, Walter Kaaden, then stolen and sold to Suzuki by Kaaden's top rider and mechanic, Ernst Degner, who defected from the GDR in the process, effectively robbing the GDR's MZ company of a win in the 1961 Grand Prix, and the Communist Government of a significant propaganda opportunity. Degner was not a popular lad back home after that, and the Stazi were not the sort of people it was a good idea have angry at you, as subsequent events confirm (read the book).
Stealing Speed follows Herr Kaaden's engineering career from Peenemünde, where he worked on the V1's pulse jet and later, the Me262 jet fighter, through his development of the two-stroke as a high power racing engine under the most primitive and restricted conditions. His design employed the rotary (Zimmerman) inlet valve, Schnuerle porting, and tuned-pipe exhaust—based on his knowledge of the V1 engine—the first known application of this principle to two-stroke engines. However, it was his addition of a "Boost" port which enabled him to achieve the magical 200 BHP per litre performance (see footnote). This is the technology "stolen" by Degner, his disciple and chief rider, and sold essentially for a song to Suzuki who were at the time, failing miserably in competition against Honda and other's four-stroke machines. Amazingly, with Kaaden's well developed design, together with Degner's knowledge, riding skill, and some "liberated" parts, Suzuki and Degner won the World Cup just one year later (virtually unlimited funding must have helped too). Even this non-motorcycle mad reader found the story of the subsequent dominance of the two-stroke in all motorcycle racing categories a very engrossing story.
Sadly, the book is somewhat light on technical detail and surprisingly, the name "Schnuerle" never appears in the text. But the exploded view of the 1961 MZ 125 engine clearly shows the Zimmerman valve, Schnuerle transfer ports, and if you look closely, Kaaden's Boost port. This lack of gritty detail is somewhat mitigated by the book's Epilog, from which I'll quote the first paragraph:
When Ernst Degner stabbed Walter Kaaden in the back and sold his master's two-stroke secrets to the Japanese, the two-stroke had yet to win a motorcycling world championship. From the first year of grand prix racing in 1949 to the year of Degner's defection in 1961, the four-stroke won 52 world titles, the two-stroke won nothing. Over the next 13 years, as Kaaden's wonder technology percolated through the capacity classes, the four-stroke won 35 world crowns, the two-stroke took 30. Over the following 27 years the two-stroke assumed a position of total domination, winning 104 titles, while the four-stroke won a big fat nothing. Only a change of rules in 2002, permitting 990cc four-strokes to compete against 500cc two-strokes in the elite class, allowed the four-stroke to win again.
As I've said twice already, motorcycles and motorcycle racing has never held more than passing interest for me, so just how much I enjoyed and was captivated by the story in this little book came as an unexpected and welcome surprise. I was thinking Four Stars until the last chapter (the Epilog). That chapter boosted it to an easy Five Stars . I recommend this one to anyone who loves engines, with some history from the darkest days of World War II and the V1 "Doodlebug", through the occupation of Berlin and Germany's division into East and West, the Cold War, two-stroke development, and the absolute nutters who rode the bikes. Great stuff.
So did Kaaden invent the Boost port? Certainly Oxley does not claim this, saying (p44) "[Kaaden] started looking for an answer in dusty old textbooks, where he discovered a 1930 Zündapp two-stroke design incorporating an extra transfer port...". So Zündapp invented the Boost port? Probably not. The image here is taken from the 1939 patent, GB512980. The patent diagrams clearly show Schnürle porting with a "boost" port, albeit with a conical piston top and what appears to be piston controlled induction porting (6). It credited to Scott Motors Ltd who had supposedly been using it on earlier Scott two-strokes dating back into the 1920's. Then credit goes to Mr Alfred Angus Scott? Again, probably not, considering Scott died in 1926, the patent being filed by Scott's Chief Engineer, William Cull! For more confusion, visit Lance's C/L Racing Site.
One could be easily excused for giving up in hopeless frustration at this point. However, regardless of who first "invented" the boost port, we can say that Schnürle porting with a "boost" port had been around for a long time before Kaaden began developing his MZ 125, although competition records suggest it did not do anyone a lot of good until Kaaden paired it with the tuned exhaust and rotary valve inlet. Confused? You won't be after the next episode...
Engine Of The Month: Nalon Viper
Longer ago than I care to confess, my pal, Eric Offen, mailed me his rough sketches and a partially complete replica of the Nalon Viper, a 2.5cc, TBR, RRV diesel conceived by its designer, Mr Norman A Long, as a serious, hand-built, bar-stock, competitor to the Oliver Tiger of the mid 1950's. This was not entirely due to Eric's normal generosity (which is legand) as I'd pleaded and begged for the chance to draw up the engine as a Motor Boy International plan set. What with one thing and another, that did not happen until this past month, but I'm pleased to say we now have complete plans (eight sheets) depicting both known variants of the Viper. In the process, I discovered some things I either didn't know, or had forgotten, so it's all been compiled into the Nalon Viper page.
The page draws on the only known published data on the engine: three articles by the late PGF Chinn which appeared in Model Aircraft during 1956 and 1957. Charlie Stone (Western Oz) provided scans of a photocopy, embedded in a MS Word doc which suggest that Chinn revisited the Viper in the pages of the Aeromodeller sometime after the 1977-8 Aeromodeller Annual was published (the article includes a photo of the annual cover). This piece was pure nostalgia, repeating some of the previous MA photos and condensing his earlier writing on the engine. But try as I might, I've been totally unable to locate the issue it appears in! On the off-chance that someone knows when it appeared, please let me know—it's bugging me...
Tech Tip of the Month
How do you remove a wrist pin that is stuck (or pressed) into a piston? Obviously we don't want to damage nor distort the piston in the process, so one way is to position said piston on a pair of V-Blocks, with space between for the pin as it emerges after gentle clouting with a light hammer and a soft drift punch (brass, or aluminum). If it does not want to come out after a couple of gentle taps, heat the piston—a hot air gun or hair dryer will do—to loosed the gummed up castor oil.
Best to conduct a close examination of the pin and piston beforehand. If the wrist pin is a press fit in the piston, generally there will be some indication, such as one end of the pin being flat and the other rounded, or one hole being slightly smaller than the other. In that case, do your bashing on the rounded end (or via the smaller hole) so that it comes out the way it went in—driving a press-fit wrist pin all the way through is a bad, bad idea.
Naturally, you can use the same set-up for inserting the 'pin, though you might find it easier to clout the pin itself to get it started in this case, provided you have a little hammer with a soft (brass, bronze, or nylon) head, finishing up with the soft drift punch.
Last Month's Big BooBoo
Last month, I managed to credit the late Les Chenery (left), with the design and construction of four engines which were actually the work of the late Eric Whittle (right). What was I thinking? I'm very sorry for this unforgivable mistake and say thanks to all those who took the time to email and most diplomatically point out the mistake. The Dec 2011 News Item has been reworded and corrected; I hope not too much damage was done and would have eaten Crow except these days, Australians traditionally eat various cold crustaceans for Christmas lunch (you try a roast bird dinner when the temperature is over 30°C).
This section is intended to alert you to little things that are hard to expand to a full news item, or cunningly wind into the Editorial, but are worthy of note never the less.
- Registered owners of Steve Huck's V8 plans should have received two updates this past month. Contact Steve if you did to get them.
- The URL in the Links Page for Dietmar Kolb's web page has been corrected following advice of the address change from Dietmar.
- I get nervous when I write something that requires an external link as they have the unfortunate habit of quietly going away. On the other hand, copying material so it is "local" is not ethical. What to do? While writing our lead item for this month, I found that two links in the Bill Wisniewski obiturary have gone 404. One is a MAN article which I can scan. The other, showing photos of Bill's workshop is probably lost and gone forever. Sad, and really nothing I can do about that. The thought of this happening to all the stuff on this site was one of the drivers behind offering the whole web site on DVD—while this site will eventually die, I hope the material can live on through all the DVD copies.