Interesting new development

Help Support


Well-Known Member
May 17, 2009
Steve Howard of Lone Star Light Sport (Texas), are development a half VW case with
Harley cylinders head.
The Javelina is a twin cylinder aircraft engine conversion based on the 1/2 VW. Using American motorcycle heads and cylinders Lone Star light sport aircraft has been able to increase the airflow over the heads and cylinders by over 30%, and the cooling area by over 130%.
This allows the use of 9 1/2 to 1 compression ratio pistons, which produces 75 hp and comes in at 126 pounds, 30 pounds lighter than a Rotax 912 80 hp engine, and about the same weight as a Rotax 582 with drive, electric start and cooling system.
We currently have 2 prototype engines.
The first is a cut aluminum case using twin cam style cylinders. 101/82mm bore and stroke. 1320cc 80 cubes.
Weight on this engine is 122 lbs.
The second engine features a full magnesium case 89/82mm bore and stroke. 64 cubes 1050cc.
Total weight is 106 lbs less starter.
We will be monitoring the temps closely. CHT and EGT are expected to be lower than a 7.5 : 1 half VW thanks to 100% more cooling fin surface area on the cylinders!.
This setup will allow for compression in the 9.5 : 1 range in the future. Hoping to achieve 60 hp at 9.5:1.
With the bore to stroke ratio of this engine torque numbers should exceed the HP numbers in the 32-3400 RPM band.



Well-Known Member
Feb 26, 2011
San Francisco
Keep us posted. I have thought of the harley cylinders and heads on the O-100 Pegasus case and crank as well. I am sure this is much cheaper. Is that a custom crankshaft?
Group Builder