Scale Model Running Challenger Flathead V8 By Ron Colonna
Challenger V8 Ignition: Spark Bore: 1 in. Stroke: 1 in. Displacement: 100 cc Max RPM: 6,000 This engine was built early in my gasoline engine building career. I received the castings and drawings as a Christmas gift from my wife. I had it running about five months later. This is the engine that creates the most interest at the shows. So much so that I've had to rebuild it twice because of wear. As designed, it had some major shortcomings. The conrods were bronze castings which promptly wore grooves in the crank. These were replaced with rods machined from 2024 aluminum. Pistons were remade and the engine fitted with rings made from the George Trimble method. Oil control rings are a necessity as the engine smokes badly without them. An electric start system was added and the engine now runs with the push of a button.
1/4 Scale Running Model Offenhauser (Offy) Engine By Ron Colonna
1/4 Scale Offy 270 This is a 16 valve double overhead cam powerhouse, with pressure oil feeds and dry sump lubrication. It is faithful to the prototype and uses the famous cup type followers. Eleven inches long and seven inches high. 1.032" Bore x 1.094" Stroke. 60 cc Displacement. (3.66 cubic in.) Compression ratio is 9.5:1. Uses solid state spark ignition. (Hall Effect with dual magnets) I knew a little about the famous Offenhausers, hearing about their conquests at the Indianapolis Speedway while growing up. I didn't get interested in building a copy of one until approached by Bob Washburn after doing my Cirrus article for SIC magazine. At the time Bob was looking for someone to develop the model, do the basic drawings, write machining instructions, and build two copies of the finished engine, in a one year time frame. He sent me all the data he had aquired at the time. I looked it all over, but had to send it all back. I was busy on other projects and it seemed a daunting task that I was sure I couldn't accomplish. I didn't forget the engine though, and some years later, a gift of Gordon White's book on the Offenhausers from my eldest son, put me in the frame of mind to give Bob's proposal a try, but on easier terms. It took me two years to do it all and I only built a single copy of the engine. I put my drawings and machining instructions in book form and published it myself. It has been a successful venture, but I was right about it being a daunting task. I'll most likely never try doing anything like that again. The engine has been, and is being built in many parts of the world. My copy has been running for eight years now and is a fine performer with the throaty roar of it's full sized counterpart.
Conley Factory Tour Model V8 Working 1/4 Scale Engine
Visit http://www.ministeam.com to purchase this engine. Working 1/4 scale working V8 model engine. Tour of how it's made as well as some light maintenance on the engine. Here is the latest in the Conley line of V-8 engines. It sports the Stinger 609 name badge (6.09 cubic inches or almost 100 cc) and is the culmination of almost 30 years of knowledge gained in the designing and construction of model engines. The new Stinger possesses no parts used in prior V-8 engines. The bore is 1.00, with a .970 stroke. It weighs about 11.25 pounds and measures approximately 14" long (from the front timing belt to the end of the transmission), 6" wide, and 8-1/4" tall. The supercharged version will be about 10" tall. Among the numerous innovative features like large oval shaped intake ports, "D" shaped Exhaust ports, and investment cast parts, two bold attributes stand tall: the dry sump pressurized oiling system and a full ignition system. The engine even has a user replaceable oil filter. For those of you who lack familiarity with dry sump oiling, it simply means that oil resides in a holding tank, rather than a conventional oil pan, which circulates throughout the engine. The oil that does collect in the pan is simply pumped back to the holding tank. I have incorporated what is call a "three stage" oil pump to move all the oil. One stage is used to feed oil to the engine, whereas, the other two stages are used to remove all the accumulated oil from the pan. This is particularly important for high acceleration, cornering, or boat applications. An important side note, my test engine held about 20 lbs oil pressure at idle and 60 lbs oil pressure at 9,000 rpm. The dry sump oiling system not only adds more oil volume but aids in engine cooling and makes sure that there is plenty of oil during hard acceleration or sharp corners. The spark plugs have a 10-40 thread. As always, the new Stinger 609 V-8 will have an electric starter as standard equipment. No hand held electric motors here, or something that fits in a box below the engine, but rather a 12 volt electric motor that is an fundamental part of the engine. It can be activated manually or via the transmitter on your remote control. The centrifugal clutch is also included.
Model V-12 Engine Runs
Check out this model V-12 engine! Gerhard Ullmann starts it up...and let's it run. www.warbirdradio.com