Lydell Engine Development Chronology

2020: Our Newest Engine, The SAP 7000.

This engine was designed as an inverter generator only, to be used as a range extender in an all-electric car (or for home use). This engine is a 4 cycle twin cylinder opposed (pistons facing each other) very high efficiency gasoline engine. The SAP acronym stands for: S is starved intake where we have been very successful utilizing a variable very high compression ratio and a variable restricted intake to hold the compression ratio at a constant 10:1 but in a smaller combustion space to acquire an Atkinson effect with fantastic results. The A is for adjustable piston specific location timing where we can fire the combustion chamber when one piston is 20 degrees BTDC and the other piston is 20 degrees ATDC nullifying compression and BTDC firing back pressure losses. The P is for power stroke pulse technology. Because this is a generator only where the engine is never connected to the wheels, we can fire the power stroke at twice the normal speed (pulse), reducing the normal power stroke power robbing quenching effect.

This engine was built specifically for a Nissan Leaf all electric car where the car can obtain 100 MPG equivalent if your house electric cost is around $ .15 per kilowatt hour. The SAP 7000 generator can generate electricity for $.15 per KWH, effectively getting 100 MPG. A normal diesel or inverter generator produces electricity at around $.35 per KWH. (35 MPG).

So, the 100 MPG 30 year mission accomplished. Hope it doesn’t take 30 years to perfect our Anti-gravity project. (Current focus)

Lydell engine development chronology.

2003 – 2015

2003: Three-wheeled test vehicle. 5.5 hp. Briggs & Stratton (B&S). Could operate as external spring pulse engine or conventional engine. This was my first attempt at designing and building an engine that allowed a very rapid power stroke by winding up an external spring during the power stroke and then using the momentum of the test vehicle to carry through the other three engine cycles. Result: Confirmed power pulse theory, 17% better mileage.

Three-wheeled test vehicle

2004: 5.5hp B&S telescoping spring loaded connecting rod, pulse engine. Result: Finger pinching machine, and basically a failure but it did run.

5.5hp B&S telescoping spring loaded connecting rod, pulse engine.

2005: 5.5hp B&S and a Stover “piston in a piston” air spring pulse engines. Result: Not the best outcome prototype engines but learned a lot. Near disaster for the Stover prototype when it fell off the test stand while it was running.

B&S and a Stover “piston in a piston” air spring pulse engines.

2006: Honda 13hp open crankcase engine, with a 4 lobe cam in place of a crankshaft, spring return. As with all my cam engines, all 4 strokes in one revolution. Slow intake, normal speed compression, quick power stroke and normal speed exhaust. Result: 4.5 cc/hp/min. We’re on to something.

Honda 13hp open crankcase engine

2007: A purpose-built automobile pusher cart with a stock 13 hp Honda attached to a Dodge Omni achieved 50 mpg @ 53 mph consuming 11 hp.
12hp pusher wheel

2007: A Ford piston, 4 valve overhead cam head and cam crankshaft installed on an antique Stover engine. Result: Used this engine for many tests.

A purpose-built automobile pusher cart with a stock 13 hp Honda attached to a Dodge Omni A Ford piston, 4 valve overhead cam

2008: Purchased 80hp electric 1993 Ford Ranger from a local city to be used as test mule for X-Prize contest. Added a 24hp Honda gas engine and 10kw generator for hybrid. Result: Drove back and forth to work; 54mpg equivalent. The aerodynamic pickup box cover made no difference on mileage.


2008: B&S 5.5hp push and pull cam engine. Result: Did run, no real test.

B&S 5.5hp push and pull cam engine

2009: Purchased 2000 Ford Focus and converted into hybrid with single-cylinder pulse engine, infinitely variable speed drive (IVSD), 3 Honda hybrid electric motor/generators, 8 Honda 144 volt hybrid batteries and a flash tube steam boiler heat recovery system feeding a steam turbine. The car was used for the X-Prize 100 mpg contest (team adiabatic). Result: Withdrew from the contest, but the car returned 75 mpg.

2000 Ford Focus Focus-drivetrain

2009: Beehive heat-conserving engine. Result: Cooked itself.

Beehive heat-conserving engine

2010: External offset crank pulse engine. Result: Good theory but flew apart during testing.


2010: 13hp Honda pulse technology engine, 15:1 compression, 6.5hp carb. No flywheel. Result: Went from 6.7cc/hp/min. stock to 5.4cc/hp/min. modified, still producing 10hp.

13hp Honda pulse technology engine,  still producing 10hp.

2011: 24hp Honda twin. Air injection, water injection, high compression tests. Result: Many, many tests, nothing good to report.


2012: 13hp Honda pulse engine with a catalytic converter, exhaust heat recovery flash tube boiler, a two stage steam turbine and twin turbos. Result: Very impressive complexity, gained 10% free power, nifty engine to watch run. The jar was condensate return level.

Heat-recovery-pulse-engine. Steam-turbine-on-heat-recovery-engine Honda pulse engine #3

2013: Twin 16hp B&S cast-iron flathead engines (64ci) fitted to make a horizontal opposed pistons with overhead valves, offset crank to bore, common combustion chamber engine. Result: many hours of testing resulting in 4.4cc/hp/min. Heavy.


2014-2015: Twin 12hp aluminum I/C B&S engines (56ci) fitted block-to-block to create an opposing pistons, common combustion chamber, OHV engine with a piston phaser that allows for adjustable 4 ci to 8 ci combustion chamber size, cylinder quenching minimizing technology, minimizing technology x 2 (no heads, big single), and piston pulse technology. Result: Best engine the company has built. Should get us into the 90 mpg highway range.


2017: Fitting the “twin12” and an 85hp electric motor/generator with a Curtis controller into our newest test car, a Dodge Neon. Returned 91 miles per gallon on a three pass tests. 2017

Dodge-Neon- “twin12” and an 85hp electric motor/generator with a Curtis controller