I studied the Horvath Patents for a long time,way back, and understand the circuits. A duplication does not need a new cast carburetor and machined spoked electrodes as in Patent. The Electrical circuit is just a beefed up capacitor discharge ignition for MAIN POWER, with improved efficiency electrolysis for hydrogen and oxygen at 40 amps, 450 watts battery draw. The spark plugs are changed to zero ohms racing type or just get Champion brand with same reach threads and remove resistor from top, and replace with bit of #12 copper wire segment. The gases flow from water safety can to a "spud in jet" as fitting on side of old 1 barrel carburetor at the venturi point. This beveled copper tube + farrow seal cap was also used on small engines on propane conversion without the expensive type kit purchase. Read Patent 3980053, then I can answer you about how it works. A 1994 Chevy Geo Metro 3 cylinder engine with fuel system injector replaced with a used, single barrel Carter carburetor would suffice. You make an aluminum plate adapter. It has a distributor that can be adjusted for timing. The Patent transformer core size was given, so as I had enlarged photo on copy machine to get size of other parts.Substitutes can be used when ordering parts as long as the necessary design systems are included. The on time of current pulses was 42 microseconds out of 100.. 1 / F = Period of frequency.10khz = 100 microseconds time. The duty cycle of oscillator was .006. (.6usec/100usec) 22 amps cap discharge = 300V DC X square root of 1microfarad / 185 microhenries coil of TR2 primary.. Frequency of pulses to SCR was 10,000 cycles. Tr1 FERRITE type transformer charges up the capacitor to 300v AC. Diodes added for full wave DC..Main capacitor HAS TO BE ONLY polypropylene 1MFD AT 1000 VOLTS DC type as LOW esr. The 22 was amps into primary of TR2. The secondary side was 10:1 ratio. The fast switch SCR is only the high frequency type like a GE model 35 amp. The reverse pulse on the primary side circuit of TR2 shuts off SCR inbetween pulses automatically. The 200A cell pulses creates more Hydrogen with the aid of magnetic field.The TR2 secondary uses NO DIODE RECTIFIER as the pulses ARE called "critical positive wave" with core as laminations, for the high frequency , instead of ferrite. This causes degraded pulse wave as positive DC. Get laminations from take apart microwave old transformer. You would build NARROW rectangle box of high temperature Gray pvc plates. . Two SS magnetic type plates and metal strips to add to each for spokes. The large Alnico or small multiple STRONG Neodymium magnets get taped to outside of box. N + S on opposite sides box. The cover gets holes for various brass fittings. Cut out rectangle rubber seal and drilled + tapped holes for cover screws.Magnetic Field is between the electrode strip gaps under water. The Oxygen and Hydrogen gaseous bubbles rise up and transfer to special brass wool type fast one way valve before entering the safety water can. Water cell should use baking soda with distilled water, so as no cleaning of container minerals build up. The Metro engine compartment is LARGE and has plenty room to work. Engine could also be put on engine stand, but you would need the Bell housing because the starter motor mounts there.. The car called Geo Metro XFI model with 3cyl did get the highest gas mileage of any car- 52MPG. In Canada it was called the Firefly. Don't forget to buy test meters such as LCR tester. The Analog type face + needle multimeters will measure volts at high frequency, not digital. Float valve attached to cover and small DC water pump, white plastic plug in breadboard for oscillator, ect, you get the idea. I have the sheet of proof reading corrections from poor Patent examiner mistakes.