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Type 1 - 1/2 VW Conversion Parts and Plans!

"Carr Twin" 1/2 VW Plans
The introduction of the "Carr Twin", as a "sawed in half VW engine", was designed by Dave Carr and was featured in the January, 1975, issue of "Sport Aviation" magazine. The "Carr Twin" was awarded the John Livingston Award for outstanding contribution to low cost flyings, as well as, the Stan Dzik Memorial Award for outstanding design contribution.

Carr Half Case above
Carr Full Case to right

The "Carr Twin" Plans offer plans for both the cut case and full case versions.


Parts are low cost and available throughout the world.

Lightweight: The crankcase is made of magnesium, 1/3 lighter than aluminum with excellent heat transfer qualities. The heads are aluminum. An 87 pound, 35hp engine is hard to beat!

Air-cooled: With both cylinders exposed to direct air stream.

Crankshaft RPM corrects for direct mounting of propellor (no need to gear down or belt drive.)

A four-stroke engine with generous bearing diameter means long life, extra reliability, and low fuel consumption.

Can be used in tractor or pusher properllor configuration.

A fun project for the mechanical craftsman!

The "Carr Twin" 1/2 VW Plans include:

Two Crankcase options: Cut case, welded or bolted together - most compact version. Full Crankcase - The quickest to build version, because no machine work is necessary on the case. Engine can be mounted directly on firewall (no motor frame required), (no oil cooler required) and the crankcase can be returned to it's 4-cylinder configuration if more horsepower is needed.

Carr Twin 1/2 VW Plans:
contain 13 detailed drawings, with written instructions.

Carr Twin 1/2 VW Plans #0058. . . $30.00
Plus postage.

1/2 VW full case kit

Full Engine Case, 92 or 94mm Piston & Cylinder Kit, 78mm or 82mm CW Crankshaft, Camshaft, 1/2 Cylinder Heads (heads are cut & welded, with Valve Covers & Rocker Arms), Shrink Fit Prop Hub Kit, Cylinder Head Stud Kit, Connecting Rods, Lifters, End Play Shims, Deck Shims, Main Bearings, Rod Bearings, Cam Bearings, Gasket Set, Cam Plug, Oil Pump, Oil Pump Cover Plate, Oil Drain Plate, Engine Breather, Engine Case Kit, Exhaust Nuts, Lock Nut & Washer Kit, Pushrod Tubes, Ubuild Pushrods, Oil Screen, Dipstick and Main Bearing Dowel Pins. (A $500 non-refundable deposit is required at time of order.)

1/2 VW full case kit #0059. . . $3970.00
Plus postage.

Engine Specifications for the Carr Twin
2-Cylinder opposed Twin 4-Cylce O.H.V.
Stroke 78mm 82mm
Bore 92mm 92mm
Displacement 1037cc 1138cc
Weight 87 lbs. * 87 lbs. *
Horsepower 35hp @ 3400 rpm 38hp @ 3400 rpm

* Full case weighs approx. 5 additional pounds.

New Engine Case(full case only) No machine work #0060
92mm Piston & Cylinders #0139
94mm Piston & Cylinders #0140
Stroker Connecting Rods #0064
Camshaft #0065
Lifters 4 each #0066
Lock nut and washer kit #0067
Oil Pump #0068
Case Kit #0069
Oil Pump Cover plate #0071
Shrink Fit Prop Hub kit #0072
Rod Bearings 1/2 set #0073
Cam Bearings #0074
Main Bearings #0075
Pushrods Ubuilds(4) #0076
Dowel Pin Set #0077

U-Build Exhaust Manifold Kit
Includes two exhaust welding flanges, two each 90 degree mandrel bent tubes and two each 180 degree mandrel bent tubes. Tubes are 8" long and 1 1/2" diameter.
U-build Exhaust Manifold Kit #0083 . . $43.95
Model 11 Carburetor for the 1/2 VW.
This is an updraft carburetor with mounting flange and mixture control.
Has idle air bleed screw also.
Model 11 Carb #0078 . . . $393.80
U-Build Intake Manifold Kit
Includes two flanges, four each 90 degree pieces of 8" long, 1 1/2" O.D. tubing and one 180 degree U-bend.
U-build Intake Manifold Kit #0082. . . $45.95

Ignition System Components for 1/2 Vw
009 Distributor Kit #0079 . . $189.69
90 Degree Distributor Cap #0080 . . . $39.95
Pinion Gear #0081. . . $52.50

To place an order: Call us at 1-402-493-6507
Inquiries can also be directed to: info@greatplainsas.com

Great Plains Aviation Supply LLC