Background, company overview and products...

Since the widespread popularity of the internet began back in the mid 1990s, we have read a lot of on-line discussions as to what makes a good VW conversion and how the conversions differ from one manufacturer to another. Great Plains subscribes to a few of the lists - just to keep up to date on "the topic of the day". As a company we rarely reply to internet groups, only making the occasional response to an individual in the group, if the group does not come up with an "appropriate answer or answers", in a reasonable time as it pertains to our product or services that may be discussed.

We believe that commercial responses over time would detract from the groups, perhaps removing some of the free exchange of information that takes place daily between group members. This exchange of information be it correct, incorrect, positive or negative, is overall helpful and informative for those participating.

We have noticed time and time again the discussion about how the conversions currently in the market place differ from each other, but have never seen a detailed discussion, point by point, as to how our company, company's engines, and components are different from the competition. So we'll fill in the details.

Great Plains Aircraft has been commercially selling VW engines, engine kits, and conversion parts continuously since 1982. This year (2007) we mark our 25th year in business. In the U.S., only RevMaster has been selling VW conversions for sport aircraft for a longer period than us.

We have seen many companies come and go in the U.S. in those past 24 years that have sold VW conversions, and or parts, or plans. To name some: Able, HAPI, Mosler, TEC, Barker, Monnett Experimental, INAV, Christeen Aero, Duty, R.J Huggins, Limbach and others. Why we remain in business and all these other companies or individuals have come and gone in 25 years, we will let you, the consumers continue to decide.

About the company - Many customers are surprised that Great Plains Aircraft Supply Co. Inc. is a family operated business with two individuals, Steve and Linda Bennett. Steve handles engine building, shipping, receiving, ordering, design, etc. Steve received his private pilot's license in 1971 flying a good old Cessna 150. Since then he has accumulated over 2500 hours of VW flight time in a KR-1, KR-1.5 and several KR-2's. In a desire to continue my education, I am also an HVAC certified technician.

Linda is the pleasant voice that answers the phone, does the order input, pays the bills and designs and maintains the web site. Linda has an associate's degree in business. Prior to joining Great Plains, Linda worked for 20 years as manager for AT&T, US West and Northwestern Bell and was the owner/operator of an AlphaGraphics Print Shop.

Being a small company, one wears many hats. The positive side is that with every order, we strive to fill it and ship it in a manner that we would expect from any other company that we would do business with. Do we make occasional mistakes? Sure. But we strive to treat the customer as we would want to be treated.

Great Plains Aircraft has maintained it's position in the market place because our company offers a wide range of time proven products at reasonable prices, we have the experience and knowledge to help customers troubleshoot problems (and not just Great Plains conversions), and we maintain this with a minimum overhead. It's the overhead that dooms many small companies when the market is slow or flooded with short term competition.

The engines.

Every engine that Great Plains Aircraft assembles, is built and test run by Steve Bennett. He puts his 30 plus years of engine building experience into every engine that we ship out. We offer a full range of engines and parts. Engines can be ordered as complete assembled and test run engines, or as un-assembled kits, or individual parts (in most cases). We can assist you in the decision process by recommending specific accessories to meet your aircraft power requirements.

The most popular engine configuration is the Front Drive ­ direct drive engine. This is driven off the pulley end of the crankshaft. Displacements from 1600cc up to 2276cc are available. A wide variety of accessories and accessory packages are available. From single ignition ­ hand start, to dual ignition, 22 amp alternator, accessory housing and geared starter - the choice is yours. We have direct drive engines to fit just about any engine budget.

The Rear Drive Engine is driven off they flywheel end of the engine. It is a direct drive engine, no gear box. It consists of a cast aluminum housing, bolted to the engine case bellhousing. A drive shaft is then coupled to a rubber torsional dampener that floats on the flywheel. Very little of the prop loading is transferred back to the engine itself. It also features a 40 amp belt driven alternator, optional dual electronic ignition, geared starter, and a mechanical fuel pump. The rear drive uses a bed type engine mount and is available only as a 2180cc engine.

The Flywheel Drive Engine is the least expensive engine configuration sold. An aluminum prop hub is bolted to a custom flywheel that is a little larger that a stock VW flywheel. The starter is mounted on top of the engine, laying over the engine case. It utilizes a 40 amp belt drive alternator, mechanical fuel pump, and optional dual electronic ignition. This is also the lightest VW conversion sold with the fore mentioned options, weighing in at 158 lbs. for a 2180cc engine. A hand start engine version with single electronic ignition, but no starter, weighs in at only 146 lbs. This also uses a bed type engine mount. The engine that can be produced in displacements from 1600cc through 2180cc.

The Reduction Drive Engines have really opened up the range of aircraft that can use VW power. Direct drive VW's are limited to a 62" diameter prop because of tip speed. They will produce about 200 to 250 lbs. of thrust, depending upon prop manufacturer. The reduction drive engines can turn prop diameters from 72" with a 1.6:1 ratio and up to a 103" prop with a 2.47:1 ratio. Static thrust with a 72" prop is about 350 lbs. The 2:1 ratio with a 84" prop will deliver about 450 lbs. of thrust. A 103" prop on the 2.47:1 will deliver almost 600 lbs. of thrust.

The re-drive engines are available in kit form, assembled and test run, or you can purchase just the drive itself and build your own engine. The two most popular engine sizes are the 1915cc and the 2180cc motors. The standard set up features starter, 22 amp alternator, 009 type distributor, choice of drive ratio, top mounted Weber carburetor and intake manifold, accessory case and remote oil cooler. They can be fitted with either dual electronic ignition or can use one magneto and one electronic ignition system. The re-drive VW engines are used in many of the WW1 type aircraft - Zenith 601 and 701, several of the Cub look-alikes, Storch replicas and a few trike's (flying wings). They can deliver outstanding take off and rate of climb, when matched to the correct aircraft.

Aluminum Nikasil Cylinders ­ With the addition of our aluminum nikasil treated cylinders, we offer the lightest weight direct drive engine available weighing in at only 155 lbs. Our flywheel drive engine weighs in at 148 lbs. Both of these weights are for a complete running engine with all accessories. The aluminum nikasil cylinders will save 10.2 lbs. on any engine they are used on.

The Products.

For starters, we offer a complete range of engine kits, assembled engines, drives, accessories and individual parts for sport aircraft that is unmatched by any company in the U.S. or worldwide. Bearings, cams, stud kits, heads, cases, accessory case kits, cooltins, carburetors, secondary ignition systems, magnetos, plugs, wire sets, 4 different prop hub styles, instruments, piston and cylinder sets ­ you get the idea. If it's a product for VW power, we probably carry it. We also make replacement parts for some of our former competitor's engines.

So what makes our engine different?

Ok, let's examine our 2180cc direct drive engine with dual ignition ... This is our most popular engine sold.

The Crankshaft.

The heart of the engine is the crankshaft. It has to be able to absorb, dissipate and transmit. Our 82mm forged E4340 steel crankshaft is made specifically for aircraft use. It features a rectangle flat milled key for the cam timing gear and distributor drive gear. 180 degrees from this key is the same style of key that indexes the prop hub. The crankshaft has a 3 degree taper on it that is mated to our Force One prop hub. The bolt that retains the hub is a fine thread bolt that is 3.5" long. The threads in the crankshaft are machined in the crankshaft about 3" down from the end. For the first 1.250" the thread is relieved so the pulling or retention loads is placed at the rear of the thread in the larger diameter of the crankshaft. This crankshaft is made specifically for the rigors of driving a propeller. It is not an "out of the box" automotive crankshaft as used by one competitor. In the 10 plus years this current crankshaft design has been manufactured, it has never suffered a failure.

The Force One Prop Hub and Main Bearing.

While not totally unique to aviation, it is in many respects when combined with our crankshaft. We recognized from early on from a number of crankshaft/prop hub failures with 82mm crankshafts and shrink fit and short tapered hubs, that perhaps it was not the best way to build stroker engines for longevity.

The Force One Prop Hub rides in a bearing that the case is machined out for. The Force One Bearing is pressure lubricated, utilizes 2 seals, one for dust and one for oil. The total bearing area is 4 to 5 times what a standard VW #4 bearing's surface area is. But the important point is the hub is supported in the bearing instead of being attached forward of the bearing, as is the case when using a shrink fit or standard tapered prop hub. As the fit between the hub and the crank is on a 3 degree taper, it can be removed repeatedly without wearing out either tapered surface. With shrink fit hub, the .002" interference fit will eventually erode with multiple removals.

With our Force One Hub, we can still use the brass distributor drive gear to drive a secondary or primary ignition system. Another competitors crankshaft does not have the brass gear on the crankshaft and cannot use a primary or secondary ignition in the distributor hole.

2180cc Camshaft.

Our camshaft, while based on a popular design for automotive use, is custom ground to our specifications for aircraft use. It is designed to provide maximum horsepower and torque in the 3000 to 3400 rpm band. We keep the duration low and add enough lift to pack the cylinder as full as possible. This cam lets the engine idle without lopping and offers quick acceleration without stumbling. Other manufacturers use standard off the shelf automotive camshafts. All our 2180 kits come with new lifters that feature a .024" oil feed hole drilled in the center to provide positive oil lubrication to the lifter/cam lobe face. These kits also feature 5/16" steel pushrods (no aluminum here for higher lift cams) and new rockerarm assemblies.

Most of the other hard components will be standard from whom ever you purchase your engine or kit from. The case, forged billet pistons and cast steel cylinders, oil pumps, cylinder heads, gasket sets and the like, all come from a small source of manufacturers and will be pretty common to all conversions.

Accessories.

This is another area where we are very different from some of our competitors. Starting with the accessory case, we supply a fully "closed" accessory case. This simply means the flywheel is enclosed in the case. One competitors X case features an open rotating flywheel. With our accessory case the starter position can be ordered in the 12:00, 6:00 or 9:00 position. We also offer a Diehl X case which bolts up to the standard Sonerai X firewall pattern and allows builders to retrofit a starter and 22 amp alternator without having to modify the fuselage firewall tubing structure.

We have a standard 22 amp alternator that is mounted inside the accessory case. One of our competitors has only a 10 amp alternator for standard equipment. We are often asked why we list our engines at 76 hp and Aero-Vee lists theirs at 80 hp. I suspect it's the 12 amp difference in the alternator as it takes horsepower to turn rotating magnets.

Almost 20 years ago we started using the geared starter which you now see as standard on most VW sport aircraft conversion. This lightweight 8.5 lbs. starter has an internal start solenoid, eliminating the need for an external one.

Our flywheel is unique to the industry. We are the only company we know of that builds and uses a light weight 100% steel flywheel, weighing in at only 5.5 lbs. Other companies use a combination of aluminum and steel to keep the weight down. We can boast that the steel flywheels have never had a failure. Aluminum and aluminum/steel ones can't say that.

Ignition Systems.

Primary Ignition. Yes, we still use what some competitors describe as old and antique - a magneto. But there is a good practical reason that is lost on some. The Slick 4316 magneto, does not need a power source, does not have external rotating magnets, is easy to hook up, and most important, you can start the engine by hand if the battery fails. With one competitor's ignition system, if the battery is dead or the starter is broke you won't go anywhere until you replace one or both. Their engine has to rotate 200+ rpm to start the engine. No starter, no battery - no starting.

Secondary Ignition. We offer a wide variety of secondary ignition systems that will fit just about any application. Our standard low height secondary ignition system (only 1.310" tall) fits in the standard VW distributor hole. This ignition system is the "standard" secondary on most of our engines. This system must be in the off position when starting.

The Compu-Fire ignition system fits in a standard VW style distributor. It has almost the same components as our low height secondary, but offers the full advance/retard that is found in the 009 distributor which provides easy starting as both the Compu-Fire and the magneto are in the "on" position when starting.

Vertex Magneto ­ Again, tried and true. This magneto fits in the stock VW distributor hole. It's primary use is found in gyros, WWI replicas, Volksplanes, etc. It's rather tall, but in un-cowled or large round cowling, it fits just fine.

009 Distributor - The 009 distributor can be used as a primary or secondary ignition system. When the cap is replaced with our 90 degree distributor cap it makes a lower height/attractive installation. The 009 can be upgraded to electronic ignition if needed.

Oil Pump Secondary Ignition ­ This ignition system replaces the oil pump cover plate. The bottom driven gear of the pump is modified and a shaft engages the gear. This system uses the same components as our low height system.

The low height secondary, oil pump secondary and Compu-Fire ignition systems all feature dual redundant coil packs and can fire spark plug gaps up to .042" if required.

In Review:

Take a look at our product catalog and web site. You will quickly see that we offer the widest range of products for VW sport aircraft engine conversions - period! We can, and do custom build engines to fit different airframes. By custom tailoring the engine to the airframe, the aircraft will meet or in many cases exceed the performance specifications listed by the manufacturer. If the builder prefers, they can also order from us just the parts they desire to build the "prefect" engine.

We know that even after 25 years of being in business, we still don't know it all. We are constantly learning about and developing new products for these timeless engines. We do believe that when you purchase one of our assembled engines or kit engines, you will be purchasing the absolute best, safest, insurable VW based engine available in the market place for your aircraft.

PLUS, If you are at EAA Air Venture or Sun & Fun Airshow, be sure to attend our informative Workshops!

	Great Plains Aircraft Supply Co., Inc. P.O. Box 222 Bennington, NE 68007 info@greatplainsas.com
	Orders: 1-800-922-6507 (available in the US Only) Information: 402-493-6507 or Fax 402-493-3846