Howell V-Twin 4-Cycle Gas Engine Plans PDF
Plans to build the Howell V-Twin 4-Cycle Gas Engine This is a V-Twin engine that is machined entirely from bar stock. It has no prototype as it is entirely my own design. Being a single crank pin 90 degree engine, it is extremely smooth and vibration free. V type engines other than 90 degree can not be balanced except with special balancer shafts, etc. that you wouldn’t want! Witness the vibrating 45 degree motorcycle engines…… The engine is a long stroke, moderate speed design which provides plenty of torque. A robust cooling system allows the engine to run indefinitely with a load and never overheat. Cylinders are of cast iron. Crankshaft is steel. Most of the rest of the engine is of aluminum alloy. Knife and fork aluminum alloy connecting rod ends operate on a single hardened crank pin. This configuration produces an interesting exhaust sound! An internal oil pump ensures that lots of oil gets to all the internal moving parts. The crankcase holds two ounces of oil. The engine is equipped with ball bearings on all rotating shafts. A sheet metal shroud on each cylinder/head directs cooling air from a pair of belt driven fans. Dual 2-Jet Throttles have oiled foam air cleaners. The valve rocker arms have ball bearing rollers on the valve stem end and clevises with lock nuts on the push rods for valve clearance adjustment on the other end of the rocker arms. The valve train is designed so that there is no side thrust on the tappets or the rocker arms which causes undue wear on other engines. The engine operates without any oil getting on the outside due to “O” ring seals at all joints and an efficient crankcase check valve ventilation system which maintains negative crankcase air pressure. The ignition system is twin Hall sensor and twin TIM-6 electronic ignition modules and two model engine coils operating on 6 volts. Each cylinder is treated as a separate engine and this precludes the need for a distributor. The spark advance/retard is easily adjusted during operation. Spark plugs are the low cost 10mm NGK CM-6. This is NOT a beginners project, but anyone who is particular about his work, has built a few other successful internal combustion engines and has a 7 inch or larger lathe and a milling machine with a 6 inch rotary table should not have any problems building this engine. Besides just being a nice engine to have and operate, this engine would be great fun on a bicycle or in a radio controlled boat, car, tank, etc.! This is a small “real world” industrial quality engine capable of doing “long hours” of hard work. My engine operates all day long at shows driving a generator and is stopped only long enough for refueling. The plans include all engine features in the photos (except the mounting rails) including the throttles, cooling fans and air shrouds, plus an ignition system schematic diagram and timing gear cutting charts. The quality CAD generated and laser printed plans set consists of 41 sheets of drawings and 3 sheets of construction notes.Specifications: Flywheel Diameter: 4″, Cylinder Bore: 1″, Piston Stroke: 1-1/4″, Compression Ratio: 5:1, Displacement: 1.96 C.I. (32cc), RPM Range: 800 – 4,500, Height: 6.9″, Width: 8.3″, Length: 5.8″All of our plans projects are machined from metal bar stock (supplied by you, the builder) and no castings are required. This is the lowest cost way for you to build as the metals can usually be purchased from metal salvage yards for around $2.00 or so per pound for aluminum, brass and stainless steel. But as can be seen, most of the model engines are designed to look like they were in fact made from castings instead of rectangular blocks and round bars of metal. High precision machining is required. Experience building other types of engines from scratch is suggested.You will need a lathe and a milling machine with the usual tooling items. You will need a horizontal/vertical rotary table for your mill if you want to duplicate the visual design aspects of some of the projects – spoked flywheels, fluted columns etc., but the engines will operate just as well without those features. Please note – we do not have any ready to run engines or bolt together engine kits for sale. The plans are for model engines – the engines can be scaled to any size, but no claims of suitability for practical power generation are made.The Plans Set drawings are high quality computer generated drawings using a professional CAD (Computer Aided Design) program and printed on 8-1/2″ x 11″ sheets with a laser printer. This permits you to insert them in plastic sheet protectors so they won’t get soiled as you use them in the shop. Dimensions are in U.S. inch decimals – no fractions – which makes it easy for you to change the scale of your model to suit your machine tool capacity or the materials you have on hand or have access to. Multiply dimensions by 25.4 to obtain millimeter dimensions. NOTE: If you want your plans right away, send us a message with your email address and we will email you a link to download a PDF of the plans. If you are successful in downloading, we will cancel mailing of the hard copy and refund 80% of the eBay shipping cost. We are the owners of this copyrighted material. Sale or giving away our plans is strictly prohibited!
