This page contains a montage of engine pictures from prolific builder, Les Stone. Les has been a great supporter of this site and hardly a month goes by when he does not provide another picture or two for us to enjoy. So Les, this page is for you!

	This V Twin was designed by the late Les Chenery, with plans appearing in the British magazine, Engineering in Miniature during 1983. Les (stone) completed this this example in 1998. The engine has a bore and stroke are 13/16" by 7/8" for a total displacement of 15cc. It was designed for either spark or glow ignition and Les has built his version for spark ignition with a neat distributor hanging off the gearcase. If you'd like to make one, see the Hemingway Kits website for plans, castings, and material kits.
	Here's Les' Chenery side-valve 5cc sparker finished in April, 2008, although the castings were first advertised way back in SIC issue #4. The engine was serialized in the English magazine, Engineering in Miniature and Les followed that series, knowing it's usually easier when someone else blazes the trail. The drawings carry a date of 1984 making this design 25 years old. The photo of the engine in action illustrates a very practical idea: get a healthy spark from a big coil and bettery until the engine is sorted out and it's running, starting, and tuning characteristics are well understood. The cooling fins, or rather the lack of them, is one of the things that leaps out when you look at the engine. But note that the fins are tapered which makes them better at heat dissipation than simple parallel cut ones. Les says you can touch the head right after a run, and while you won't get burnt, it's not a particularely fun thing to do. Tapered cooling fins, still used in full size air cooled engines and much favoured by Westbury are seldom seen in model engines these days where lots of slit fins are more the norm. I rather like the look of the old ones. As Les says, it's a Classic.
	This is an Original Ohlsson Les made in January, 2008. I think he is spot on regarding the need to drop the combustion chamber roof: Irwin Ohlsson and Harry Rice produced a long line of engines from the first days of "sparkies", right up into the early 1950's. My first engine was an Ohlsson & Rice 60 sparker. I was ten years of age at the time and purchased it at a local hardware store with newspaper route earnings, the price at that time being about $14.00 NIB. The original Ohlsson seen here wasn't one of Irwin's production engines, but instead, was one of his first prototype engines. The story of this engine and the Popular Mechanics plans that appeared for it in 1937 are detailed in Roger Schroeder's series published in SIC, issues 6 through 12. Roger still supplies plans and castings for this engine, but I've had kit #160 on the shelf since February 20, 1991, that's 17 years ago. So I deemed this 1934 original Ohlsson kit an appropriate build and fitting tribute that marked the introduction to my O&R collection. The moving point on this original Ohlsson was made of the same material that was supplied in Art DeKalbs Elf Goose Egg 4 casting kit, which he had listed as Phosphor Copper sheet, 0.015 thick. There was ample material left over from the kit that would allow another moving point to be made for the original Ohlsson, which can take a bend way past 90 degrees without breaking and still retain it's bouncy, resilient spring tension, that is required for this particular moving point. Regarding the spark plug, ECJ states on page 4, volume 4, number 5, April, May, June 1966 and continued on page 16, volume 5, number 2, November, December 1966, that the first 3/8-24 production AC (Albert Champion) and Champion spark plugs started production in 1936 and 1938 respectively. This was late for the 1934 Ohlsson, so in order to bring the authenticity in more accurately, I replicated the spark plug that is shown in SIC #7, page 11, which is a photo of the actual first original Ohlsson, built by Irwin and a close associate. From my own judgment and experience, the combustion chamber space was excessive in the first Ohlsson, but supposedly, this was the order of the day at the time this engine was built. I wanted to improve performance and also achieve a good reliable 2 cycle run, while retaining the originality, so the first item to take care of was to keep the 1934 theme of things on the outside, but cut down on compression space inside. The original spark plug I made for this engine had the Corian insulator coming all the way down to the bottom of the 3/8-24 thread, this in effect closed out the underside of the spark plug that was left overly open in the early V-type spark plugs which added to the head volume, lowering compression. The plans show a screw-on head but I did a blind bore, decreasing the distance between the roof and piston baffle by 0.060" at TDC and making one less place for compression leakage. The one other location to use up compression space was in keeping metal from the top piston baffle, down to the piston flat, on a gradual concave radius and to terminate with the bottom exhaust ports at BDC. It all must have worked because the little 0.12 cuin engine ran well on a gigantic 9x4 wooden Flo-Torque prop, giving 5600 to 5800 RPM.
	This little beauty, Les' October 2007 creation, is a Custom Humbug and you'll have to read the reference under the link to find out why. The intent of the design was an engine that could be made without thread-cutting, or any specialized tools like slitting saws and milling—all plain turning, drilling, and tapping. Les found that suction was a problem which he addressed by inserting a sleeve in the venturi that reduced the internal diameter from 0.140" to 0.125". This fixed the problem and the change has been made in the plans. The figures on it are Bore 0.5", Stroke 0.46", for a capacity of 0.09 cuin (1.481cc). As seen in Les action shot, it is turning a massive 12x4 wood prop at 5,000 rpm. Les says that as he's getting on a bit, big props slow the engines down to a point where he is sure of his fingers getting out of the way first! The extra flywheel mass helps on first starts too. Les has built this one as a straight rear rotary valve diesel, but the plans show how it can made convertible for either diesel or glow ignition, and with RRV or reed valve induction. In the "bar-stock" configuration—simply known as the "Humbug"—it is rather pedestrian in appearance, but if Roger Schroeder's castings are used, the appearance is totally transformed. Plans are scheduled for a future edition of Model Engine Builder magazine and it's great to have Les' help validating the design so readers will ultimately benefit from his experience.
	Like the rest of the Motor Boys, Les likes subjects that are just a little out of the ordinary. The MS 1.24 qualifies by having the forward facing side-port intake, and the co-axial fuel tank. "MS" stands for the Model Shop (of Newcastle, England, see Model Engine News, March 2004 for more information about the company). The engine itself was first seen here in 2004, and later, was the subject of a slightly more in-depth review. An example of the original engine reputedly sold at a Guilding's Auction (UK) for 450 pounds! Les' example was produced from his own casting, poured using a pattern made by Graham Podd. Les says: I received a package and letter from Graham Podd in November of 2005 containing his pattern of the MS 1.24 saying it's yours to keep if you want it, I have my one example of the engine, so no longer need the pattern, needless to say, I gratefully accepted. The pattern laid around for a couple of years and finally became the center of my current project. If you look at the pattern closely, you can see how he bent and attached the fine copper wire to form the letters "M S". The photos show my finished engine and one of it running with a Top Flite white nylon 9x6 prop. I tried the tach, but numbers were jumping from 5000 to 10,000, and then back again. It wouldn't stay in any set range yet the engine stayed at one set speed—maybe low batteries, or they sat on the shelf too long.
	Here's Les' rendition of the Thorning Monsun, a vintage 2,4cc Danish long-stroke diesel from 1945, or there-abouts. The engine is remarkably advanced in having Schnurle-like transfer porting—used here then forgotten in model engines for the better part of the next twenty years! Les moved the exhaust from the rear to the front as he felt that the cluster of ports at the back were all just too close together for comfort and acceptable timing. There is even historic precedence for this. Have a look at the Viking, another long-stroke diesel from Denmark. The other thing here that looks rather like a bathroom fitting is the nose piece. Again this shows Les' lateral thinking on how to make a complex part simpler. If it does not look simple, have a look at part 5-1 on the GA of the Monsun that shows the part formed and fitted as designed. Les reports that the engine was initially a bear to start, but is loosening up nicely and really moves a lot of air turning a Top-Flight 13x5-3/4 wood. Try that with your average .15!
	This bar-stock engine was designed for first time builders by Andy Lofquist. Andy's operation is called "Model Lathe Accessories", hence the name MLA Diesel. The MLA kit for it included three double size drawings along with 4 Allen head nuts, one taper pin, 3 Viton 'O' rings and one small container of diamond lapping paste. It has a bore of 0.500" and a stroke of 1.000". Les has this to say about it: You may notice my head has an unusual shape as compared to Vincent's perfect sphere shaped head. In Andy's instruction booklet, he presented a table of coordinates, but I misinterpreted diameter for radius and dropped into the head too abruptly, so had to re-group if I was going to save it. There was enough previous machining on the head that I didn't want to go through this again. If you catch a side view shot it, the resemblance is that of a pith helmet—needless to say, the day was saved. It starts very easily, just one choke and it's off and running; 5,200 RPM on a 12x6 prop. Pith helmet yes, but more like an acorn to me (not that we actually have such trees Downunder, so what would I know). For an example of how it might have turned out, have a look at the one made by Dr Battiwallah himself, Oz Motor Boy Vincent Chai. A picture of Vincent's example graced the front cover of SIC #78 and provided Les with the spark of inspiration needed to finish his.
	This project was completed by Les in May, 2007 after ten months of effort. The subject is a quarter scale 1909 Anzani Fan Aero Engine, originally designed by Alfred Eichinger of Sieghartskirchen, Austria, which appeared in the final three issued of SIC. Les says that the most significant change he made on this particular engine was to the ignition system (Unterbrecher). The magneto is a dummy concealing a distributor running at half engine speed off the center camshaft for number one cylinder. The engine base is comprised of two one inch thick laminae of Black Walnut hardwood, which gives the base it's final thickness of two inches. Like all Les' engines, this is a "runner", not just a "looker". which raises the question of how does it sound? When asked this burning question, Les provided the following description: "...Da Da—Dum, Da Da—Dum, Da Da—Dum..." Real old fashioned, just the way it should sound! The reasoning behind this is the firing intervals. The firing order is 1-3-2. The rotation is counter-clockwise viewed from the front of engine with cylinder #1 at top center, #3 on the right, and #2 on your left. When cylinder #1 fires, the crank has to go around 288 degrees to put #3 at TDC for firing, after 3 fires it only has to rotate 144 degrees to put #2 at TDC for firing, so from #2 it goes 288 degrees around to #1 again. The cam I made runs at half engine speed and has 3 lobes. The angle between the lobes is effectively cut in half. Looking at the top of the cam is #1 lobe, then drop down towards the bottom of the cam, 144 degrees either side of #1 lobe and add two more lobes with only 72 degrees between them on the bottom of the cam. So the two that fire closely together are "Da Da", and the more distant one is "Dum". Incidentally, there are no wasted sparks on this set-up.
	Here we have Les' rendition of the Majesco Mite, a rather rare little British diesel from our Motor Boys CAD plans, prepared from sketches kindly provided by Motor Boy Ken Croft. The engine it's posed against in the second photo is a Topsy, another Brit design of rather distinctive and similar appearance that was designed by Mr G Hugh and serialized over four issues of the Aeromodeller, starting in February, 1969. Regarding the Mite, Les says: I got 5 tank-fulls through the Mite today (2006-09-09). The photos show it together with Topsy, two real powerhouses so to speak. This is about as close to Gasparin building as I ever want to get! The diameter of Topsy's piston is 5/16" followed with the Mite piston being 3/8". The Mite swung a Top-Flite 8 x 6 white nylon prop at a very respectable speed. The side view shot shows the bypass cover on the Mite which is .020 thick stainless steel. Les used no castings for his Mite. The basic case is hogged from the solid. The venturi was pressed in and a fillet of JB Weld used for added security. Les swears by this stuff. It dries grey, so he's touched it up with silver paint to resemble a first-class TIG welding job. If you look closely, you'll notice the fins on the engine are "thread form". Evidence shows that originals exist with this rather extreme example of tapered fins and more conventional straight fins. I think the tapered ones add to the period charm of the engine.
	This is Les' rendition of a twin that appeared in SIC #15 of June/July, 1990. Les completed this one in February 2004. It was designed by Australian Stan Hinds, hence the name "Hinds Twin". As twins go, it's a relatively simple and very practical engine to build, being based on commercial cylinder liner/piston assemblies—PAW 1,49cc units in this case (notice the characteristic PAW "dovetail cut" of the exhaust openings). While using finished cylinder assemblies helps, no twin is all that easy to build when you get to the crankshaft(s). The Hinds Twin is alternate firing, so the central "spool" has two inlet ports 180° apart with a deflector piece that is angled between them, sealing them from each other and providing the alternating induction from the single venturi. This results in two bangs per rev and Les says it does not just howl, it positively SHRIEKS!
	First, here's what Les had to say when he sent out the pictures: Hi all, finally the big brother to the Lindberg Hornet A which was received as a casting kit from Roger Schroeder February 15, 1984—22 years ago and was my introduction from steam into internal combustion, a sudden change that really presents more of a challenge. The castings and construction series for the Lindberg Hornet C have been on hand for a number of years as received from Denny Hitson. All this aside and on to the main ingredients of the Hornet C. The case, cylinder and head are all threaded to screw into one-another. This eliminates the 4 hold down bolts and to a degree resembles an O & R aluminum head staked on to a black cylinder. The ignition set up shown on the previous drawings I sent was inadequate at best. I had an O & R moving point, so decided to turn down a housing and pivot post for it. This worked out all right. The amber fuel tank is a new repro Super Cyclone tank made to work with some modification, because there were 2 tank options given on the drawings, that is out of metal or Lucite ! That's a term in reference to plastics I haven't heard for a long time. Finally, the prop you see swinging in one of the attached pics is a 14x5 REV-UP wood. I still get that thrill firing up an engine that you've spent a considerable amount of hours in it's building process. Now read between the lines. Les' Hornet B exhibits all the skill and hallmarks of his Hornet C. They sure don't look like they were build 22 years apart. Next, look at all Les has produced in a mere 22 years! This page is by no means exhaustive; it omits all his multy-cylinder engines, including the pair of Furgerson boxers, an Elf Goose-Egg, a deHavilland Gypsy 1 and a Hodgson 9 cylinder radial!!
	Les' version of the Sugden Special has some touches of his own, some obvious, some subtle. The backplate mounted tank is the most obvious. Not so immediately obvious is the changes Les made to the cylinder retention. A close look at the area around the exhaust ports shows that the bosses for the liner hold-down screws have not been used. Les prefers a screw-in liner, so that is what he made. As the transfer passages are external on the Sugden, this makes the lower portion resemble a big thread cutting tap, and one starts to think of possible trouble with cross-threading. But Les reports this is not a problem and in fact, there have been commercial engines that were made exactly like this and survived contact with their owners. Impossible to see from the outside is the change Les made to the crankshaft. As shown on the plans, the Sugden featured a dual diameter journal, running partially bronze bushed, and partially unbushed in the case material. Les' shaft is a constant diameter, running unbushed in the case. Some simple re-design provided the same inlet timing as the "standard" Sugden. This sort of modification will make purists shudder, and pragmatists nod in appreciation. Obviously the engine itself does not care, as it runs just fine. Incidentally, the case is a sand casting from Canadian Motor Boy, Andrew Coholic.
	The Ranger B is a 1/2 size Brown Jr. look-a-like that you can buy for about $US300. That price was just a bit high for me, so I made the split pattern you see attached with the engine. The only cost of this engine is time and material, but that's what the hobby is all about, isn't it? This is the only split pattern I ever made because sometimes the mating pins are effected by the moisture in the sand and you don't need any pattern that is reluctant to come apart at this stage for fear of destroying the mould, therefore my preference is the solid pattern with plenty of draft.
	Greetings everyone, attached is my most recent effort, taken from October 26, 1950 Model Engineer designed by G.D. Schepel and J. Buwalda of Holland. The 1.9 CC given is misleading and is actually 1.777cc figured on the basis of a B&S equalling .470 x .625. It swings a propeller of 9" diameter at 5,500 RPM according to the article, but doesn't mention the pitch. My engine attached is swinging a late 40's/ early 50's vintage 12 x 4 Flo Torque wooden prop. I didn't tach the engine because it is still much too tight, but it sure pushed a lot of air around and sang a lovely song. I guess after one's long hours of building the engine, this comes as your just reward, even more so if you were to mount it in a model aircraft. The plans originally came from Denny Hitson about 5 years ago. I toyed with the idea of building it back then, because to me, it seemed like a very desirable engine, but other projects got in the way and it was soon forgotten. Then more recently, Graham Podd sent me the same plan and then it really put the hook in me and helped rekindle the spark I previously had for it. Several different options were given in the plan for building this engine. Three ways for the crankcase, I chose out of a solid block of 6061-T-6 aluminum. There was also two tank options given (vertical or horizontal). My choice here was vertical. There also was two choices on compression: fixed or variable. My choice here was variable. The final item that had two choices, was the front end bearing. Either bolted in and held with 3 bolts or screwed in place. My choice was the latter with a left hand thread. The attached general arrangement of the engine gives you some idea of what it's all about.
	This engine should be familiar to all regular MEN readers, although the eagle-eyed will spot some differences from the "classic" version (as described in John Brown's excellent book, Dan Calkin And His Elfs). Here's how Les describes his rendition: Quite some time ago, several of the Boys built the model 1 Elf, or as it is more commonly referred to the Elf Corn Cob. At that time, I had a kit of castings for subject engine sitting on the shelf for at least 10 years, but when I saw the Boys doing their thing on this engine, far be it for me to pass it by, so off the shelf they came. I had a near miss on losing the front half of the case, so had to pull back and regroup, hence the long bronze bearing loctited in the front. How do they say it,(if you get handed a lemon, simply make lemonade). This led me to a two piece crankshaft, the front one with the longer crankpin, and the rear one with the hole to accept the long crankpin which in turn drives the distributor. The tank is also different in that it is just that, a tank without the float. All I do is fill it up and run it dry. The piston isn't original as with rings, it is lapped to the cylinder. The one outstanding flaw at the base of the needle valve is the solder not quite joining all the way around the base. I had been tempted to re-solder the joint but sometimes in a situation like this you can open up the preverbial bag of snakes and put yourself in a worse position than you are presently in. The spark plug is homemade as per Dan Calkin out of the John Brown book page 165. If you take notice, the plug has one cooling groove cut in the hex portion of the plug as oppossed to Lew Blackmore's plug that has three cooling grooves cut in. Last but not least, I'm not a purist by any means as you can well see, and on that note I must pull a quote from Bert in regards to the M&M 23 which follows thusly, (I have talked extensively to a fellow whose father worked at M&M and they pointed out that only one man made all these things in the basement of his home. He was Clayton Merry, long since deceased. He apparently rarely made more than two or three engines just alike and constantly modified anything that pleased him. His workmanship was excellent, particularly his piston/cylinder fits and finish)—Gentlemen, my exact sentiments. See Also: Original Corncob Elf Bert Streigler's Corncob Corncob Diesel And notice the prop? This is carved from the original Elf "one size fits all" design appearing in the Elf Book. It has extra value to Les as it was carved (by him naturally) from a mahogany plank taken from a Gar Wood speedboat he once owned.
	Now I'll bet you've never seen one of these before. Les writes: This is the German B. Frank Benzinmotor EFVI Bohrung 20 mm (bore .788"), Hub 19 mm (stroke .748") Displacement 5.980cc (0.365 cuin). I got the "prospectus" of the engine from Graham Podd and sent it on to Holger Menrad. He said if I'm patient, in the spring when the snow had subsided he would drive X amount of kilometres (he never told me exactly how many) to the site where the Frank engine was. He told me that he had only held a Frank engine in hand once in a life-time, indicating the rarity of the engine. The year shown for the engine was 1940, so with the war hotting up, I doubt much that many were produced. Holger Menrad's pictures and help were indispensable and paramount to the successful culmination of the Frank engine project. Regarding the pictures, three are of my reproduction. The one with the wires is of the original engine, taken by Holger. Take note that the original has the tank followed by the waxed in coil. German sparkers often combine the coil and tank in various fashion. This project like the Condor Midget was also long and drawn out because of the time consuming developemental work on ports, internals, patterns and castings. My engine follows the prospectus with just a tank scaled up to the right dimensioning. Those old brown condenser/capacitor tubes in that size are kind of hard to obtain. One more item of interest I'd like to run by you. I made a little mistake on the spark plug after I had already finished the inscription on it. Holger writes the following back: Dear Les Yes, I received your e-mail in good quality. Many thanks for it. Compliments to your spark plug. I would be much interested how you had made it. Sorry, that you could not read correctly the inscription on the plug. The first row is O.K. "ZK" means "Zundkerze", the German word for spark plug. The row below however, should be "Flieger". That means "flyer", "pilot" or so. The threads are M10 x 1 metric to the cylinder head and M2 for the top screw. Best regards, Holger
	This is Les' rendition of the Japanese TOP .23, an ignition engine from the early post-war years. It was build from drawings Les made of an original engine. Shortly after he completed it, an article appeared in Model Engine World describing the engine and beginning a construction series for a(nother) full replica of it. As expected, the engine bears Les' "trademark signature" finish, but take special note of the spark plug. This is shop made with a brass base that gives a beautiful contrast of metals. The insulator was turned from "Corian", a synthetic ceramic-like material that has been popular for kitchen tops (bad pun). It machines easily making it well suited to this function, although I've heard that it pits rather quickly with prolonged, hard running. As Les says, with the bullet shaped spinner and tank, it's hard to tell if the engine is comming, or going!
	This is a Cave Cobra, a .60 cuin sparkie from the glory days of tether car racing. More details below in the section that shows the Cobra side by side with...
	...Les' Dooling .61 replica. Even without the name on the side, who could mistake the bypass bulge on this engine. More details below.
	Both the Dooling 61 and the Cave Cobra share an era and a purpose: to drive tether cars around a track at speeds the eye has difficulty tracking. Les reports that the Cobra was made from a casting kit that is still available from Art Dekalb (see the Suppliers page). The trombone venturi was turned from a lump of beryllium copper, which Les says was "very tenacious to machine but well worth the end result". The 7-fin Dooling .61 replica was made from castings obtained from Denny Hitson—I don't know if these are still available or not.
	Dropping in size a little, and not actually an internal combustion engine—or any kind of combustion for that matter—is this replica of an "expansion" engine of 1928 designed by Edward Pachasa, who was better known as Edward Packard of the Cleveland Model & Supply Company. The original plan appeared in American Modelmaker. For a time, Roger Schroeder of Classic Model Engines was able to offer kits and plans for the engine, and Les' example id from one of those kits. The plan, and the history behind it was serialized in Roger's regular "Engin-uity" column, beginning in the March-April 1969 issue of the Engine Collectors Journal. Compressed air engines like this were the only alternate to elastic power for model aircraft during the first quarter of the last century. While the air tanks were quite bulky, they and the engines were light and produced a truly remarkable amount of power—though like rubber, they tended to produce a burst of power that tapered to near useless towards the end of the run.
	I dedicate this work with tribute to the late Miguel Devezeaux de Rancougne with an enormous thankyou to my good friend, benefactor and associate Graham A. Podd Who was ever so helpful, especially with the loan of the Etha diesel which was once in Miguel's collection. Without Graham's involvement, this endeavour would have never left the starting gate. Unlike the boys, I don't have an RPM gauge, but try to tune my ear to it while it is running. I've been doing this since I was ten years old and that was 60 years ago starting with an Ohlsson 60. The engine ran at a very respectable speed swinging a Top-Flite white nylon 11-7 prop. The needle valve wasn't at all sensitive and adjusted out nicely. Appearance and operation came up to my highest expectations. Best Regards, Les The Etha, while less well known than the Dyno, is generally accepted as being the first commercial compression ignition engine to appear on the market.
	Ron, as you could readily see, there is much over-kill in the design, but I guess that was state of the art in 1938. You also see the reasoning I went for the blind bore on the cylinder. The crankshaft and front cam timing had to be done with ingenuity, because these were two of the parts that were missing from the series. It is interesting to note how things were accomplished on small engines back then when the hobby was in its infancy. The bore and stroke is 7/16" X 1/2" respectively. The plan called for a screw on head but I thought this was a lot of over-kill or over design which wasn't necessary, plus the fact you were getting into watchmakers work if you went this route. I queried Bert when I saw his finished Pepp. He told me it was finished with Birchwood / Casey "Perma Blue" Liquid Gun Blue. I went to an area gun-smith and he ordered me a 3 oz. bottle. This is what I used on the little Deller. RC: The "Deller" appeared as a comprehensive set of vague hints on how to build a 1cc spark ignition engine in the English magazine "Newnes Practical Mechanics", starting in the January 1938 issue. For the full story, visit the Deller page.
	This is Les' rendition of the Sky Charger. The original engine, which was never put into production, was the product of Hollywood screen actor and model shop owner, Reginald Denny. A copy of the design drawings found their way to erstwhile SIC editor/publisher, Robert Washburn, way back before he launched his magazine. At the time, Bob was writing for Home Shop Machinist. The full plans and his very detailed article on building the engine (and jigs to assist this task) were published there. Ultimately, it was the lack of editorial interest in IC engines in general at Village Press that led him to found SIC. Robert says 42 sets of castings went out after the build article appeared in HSM. As far as is known, apart from the ones Robert himself built, only two have been completed: Les' example seen here, and another by Ron Colona.