I had an OS FS-120SII I was going to run with ignition and gasoline. I found a suitable Walbro carb, but it needed a few parts to mount to the engine. Details can be found here OS FS-120SII Gas Glow Conversion. There is also a video of machining one of the parts required on a small Emco vertical machining center PC Mill 125.
The engine does run with this carb and the OS G5 glow plug, but requires plug heat to run well. Increasing compression ratio should improve running.
Finally, within a week there will be closure to the Enya 41-4C disassembly video, but it won’t be as expected.
I’ve been thinking about this project for a few years. Recently, I spoke with a friend who had the same idea and it renewed my interest. The original concept was to somehow modify the existing fuel regulator to be compatible with gasoline. The YS system contains a fuel inlet “needle” which is made of silicone. Silicone swells in gasoline so this won’t do. Later, I had the idea that I could avoid the YS regulator by using Walbro metering components or a Cline Regulator. These are compatible with gasoline but not easily adjustable and I wasn’t sure what the fuel delivery would be like. Eventually, I settled on making a new regulator of the original design incorporating compatible materials and minor changes for fuel delivery. The regulator replaces the stock unit. Inside the engine silicone seals were replaced with Viton. The original check valve also uses a silicone flapper and was replaced.
The ignition system is typical with a sensor mounted on the front bearing housing and a ring with a magnet over the drive hub. A Rimfire 1/4″-32 spark plug was used. I decided to start with 16:1 fuel using SPL Avenger oil. This may or may not be enough oil and I won’t find out until I have a lot of time on the engine, or sooner. Fuel is VP Racing SEF 4-Cycle.
Finding the regulator setting to get the engine started didn’t take long. The needles were very sensitive, but this was expected. I may be able to make a change to the regulator to reduce the sensitivity. It tune well by adjusting all three settings, regulator, main needle, and idle air bleed. I shut it down and went for the camera. The engine refused run well and sometimes it wouldn’t start. It took some time, but when I needed to refuel I found the answer. Disconnecting the fuel lines I expected the typical tank pressure discharge, but there was none. The check valve stopped working, so I found another. The resulting video is a bit short because the camera was on for a long time and the battery gave up.
Browsing some sites with photos from the Nuremberg Toy Fair this past weekend a few new engines popped up.
Browsing some sites with photos form the Nuremberg Toy Fair this past weekend a few new engines popped up. Weston UK was displaying a few new or prototype offerings from RCV Engines. There was a CD-260 twin and marine versions of the existing CD series. The old ED engines in the case were curious, I think Weston UK owns what was E.D.
Thunder Tiger displayed a Wankel 50CC gasoline engine. This is certainly interesting. The price will of course determine if it become common or not, but there will always be some market for unique engines.
And for the model engineering followers there were some interesting offering from Böhm of Germany. The stirling engine cars are intriguing. I didn’t know of this company until now, but they are well known. Click here for the Böhm website.
I’m working on several new pages to add to the projects page. I have not been idle, but progress has been slower than expected. There’s a high speed milling spindle, cnc lathe, a sad end to the cox project, and some other engine info. I hope to get the site refreshed in the next week or so.
This past weekend I made a stop over at the Chicago Model Engineers Association’s annual show. This is a small group and that makes it fun to visit because it’s not crowded and you can talk without being rushed. I did not forget the memory for the camera this year.
Last year I posted a video of the FS-48 at the flying field. I have installed a Robart fueling valve and Cline fuel regulator. The fuel regulator improves consistency of mixture setting for the large 13 oz on-board tank. The valve allows starting and warm up with an auxiliary fuel tank containing standard model diesel fuel. When the valve is closed the engine draws from the on-board tank of fuel without ether. After final needle adjustments, it’s ready to fly. I also replaced the stock FS-48 needle with a different part number that fits but has a much finer taper for improved needling. The starting procedure is much improved and only needs a tank that will sit on the model without assistance. The video is here. I flew the model last week, at mostly high power settings, for 25 minutes an landed with 2/3rd’s of a tank. The run time is fantastic. Setting the engine is a little tricky with etherless fuel, but it’s and interesting experiment.
I didn’t read many books in the past. I gathered most of my information about engines from magazines and internet sources. This was OK until I ran out of depth in the material. There is plenty to read, but pretty soon it’s all the same. Books go much deeper and I found that I enjoy reading about the men who created these machines. Aviation engines interest me the most, but I won’t skip any engine book. I have some technical books that are very in depth in engine theory and design. These are not very entertaining unless designing an engine. Recently, I’ve found a few biographies that caught my interest. The first was “Fedden – the life of Sir Roy Fedden“, about the man who designed the great piston engines of the Bristol Aeroplane Company. I’m now reading “The Ricardo Story” about Sir Harry Ricardo whose research brought major changes in engine design. I also have “Not Much of an Engineer” about Sir Stanley Hooker who had major roles at Rolls Royce and Bristol. An overview of piston aircraft engine designs “”Development of Piston Aero Engines” by Bill Gunston is an excellent reference with many photographs and drawings. On my list to get are “Memories and Machines: the Pattern of My Life” and “The High-Speed Internal Combustion Engine” by Sir Harry Ricardo. These are collectible, so they are quite expensive. These books give a wonderful history of engine development and the people behind the work.
The IHobbyExpo show has certainly changed since I first attended 15 years ago. The economy and the internet have reduced the number of exhibitors and visitors. New products are often found on the internet before the show. Still, some manufacturers manage to keep a few things quiet. On to the good stuff.
OS Engines will be introducing a new fours stroke by the end of the year, the FS-95V. The head appears similar to the head used on the FR7-420 radial.
Horizon Hobby displayed the Saito line up included recent additions; FA-200R3 and FG-57T.
UMS Technologies LTD of India was present for the first time. UMS produces the Siedel Radials. New at the show was the smallest they produce, ST 7-35, A seven cylinder radial displacing 35cc. It’s rated at 2HP and 5200RPM maximum. UMS also had stirling engines on display. I neglected to ask about the 6 cylinder automotive type engine.
Authentic Scale is producing a line of engines. The first that will be available is the 9 cylinder, 90CC, 9-90M Radial. They are also going to offer a V-12 and double row 14 cylinder radial. These are Martin Ohrndorf designs.
I see it’s been a long time since I’ve posted. I’ve been busy with a new baby boy and several projects on top of work. I did manage to attend the NAMES event this year. It was interesting as usual, but I didn’t get any photos this year. I visited with a friend and did get a chance to run his Schlosser 0.25CC diesel. Wow, was that nice engine. Being brand new it felt incredibly good and doesn’t seem like it will need much run time before reaching full potential. Unfortunately, I forgot to get a photo or video.
The FS-52 with spark ignition was written off in a crash that totaled the airplane. One of these days, it will be repaired. Read about what I learned in the teardown. A spark conversion of an FSa-81 is almost complete.
I added a page about a camshaft swap I’m doing in one of my diesel FS-48’s to improve consumption. The engine needs a few more items and will be test run soon.
I also uploaded a few manuals to the download page today.
I’ve been adding some videos to the How To page. I hope to add more as time is available. A Saito rebuild is next on the list. A few new engine manuals have been uploaded to the Download page. I have more to scan and upload in the near future. I am considering offer several new diesel OS FS-30 conversions before the end of the year. Please contact me if interested.
I made a brief trip to Oshkosh, Wisconsin yesterday to the EAA Airventure event. I didn’t have much time and could have spent all week looking at aircraft and engines. I have flown electric model airplanes since 1997, and wanted to see the Yuneec E430 two place electric first hand. I also stopped in at the NASA display and had a look at some sUAV projects.
I finally decided to make a bearing puller to remove camshaft bearings from OS four strokes. These can be, at times, very hard to get out by heating the crankcase. This tool lets me pull them without any issues. Slip the tool in and crank it out with a wrench.
Winter has overtaken Chicagoland in a big way. It’s unusual to experience this much snow and cold, then get a rainstorm and warm temps to wash away almost all of the 10+” of snow on the ground. There were even tornado watches. So as winter makes it hard to fly much, I’ve been working on some projects in the shop. I’m working on a small engine dynamometer. It’s fairly complicated and I’m still gathering parts. I will be able to measure airflow, fuel flow, rpm, torque, cylinder head temperature, exhaust gas temperature, intake temperature, and hopefully combustion chamber pressure. I’m doing an spark ignition conversion of a Magnum XL-91 RFS for a friend. The engine has hundreds of hours on it and is getting new bearings, new piston, and new ring in the process. I have an interesting project involving a Cox .049 in the next month or so. I continue to work on the FS-91 diesel conversion. I’m setting up an airplane for it and hope to fly it in January, if weather allows. The airframe will carry data aquisition equipment to relay in-flight information about the engine.
I’ve flown the FS-52 with spark ignition with methanol fuel. The fuel was 8% Klotz Original Techniplate and balance methanol. After test running the engine with this fuel at home, I checked for oil under the rocker cover. There was plenty. I’m convinced the crankcase ventilation system works as it should and draws oil through the engine well. Flights went well and the engine starts easily. I’m very happy with the outcome. Before it get too cold in Chicagoland I plan to test run E85 and possibly gasoline fuel. I’m concerned that oil for gasoline wil not blend with the alcohol compatible oil already in the engine. This may require a flush of the crankcase. Click the image for a link to the project page.
I’ve added photos of the FS-52 spark conversion. I haven’t flown it yet, but expect to run and fly the engine in a few days. I expect it to run well. I have learned that the RCEXL ignition will operate well past 8,000 RPM and the 10,000-11,000 RPM I expect to run at will be no trouble at all.
I added several items to the Swapmeet page. Several engines excess to my needs right now and a list of engine parts I have available for sale or trade. There are many Enya fourstroke parts, many O.S. parts, and a few Saito parts.