How to Run a Gasoline Engine on Hydrogen

Hydrogen is a combustible fuel that can perform similarly to gasoline in a car engine. Hydrogen has a simpler molecular structure than gasoline, and as such, produces less pollutants when it burns. While it is also possible to lower fuel costs by converting a gasoline engine to hydrogen, the initial setup cost is often a deterrent. Converting an engine to run on a hydrogen fuel supply is very complicated, and may require extended troubleshooting. However, if you are up for a challenge and have plenty of time and material resources, it is possible to convert a gasoline engine to hydrogen.

Things You'll Need

  • Full mechanic's tool set
  • Hydrogen tank
  • High-pressure tubing
  • Assorted high-pressure fittings
  • High-pressure regulator (1000 to 4000 psi)
  • Medium/low pressure regulator (50 to 1000 psi)
  • Machine shop access
  • Hydrogen or natural gas fuel injectors
  • Drill and tap set
  • Throttle position sensor
  • Programmable engine control computer
  • Optical sensor
  • Laptop computer
  • Engine tuning software

Modify the Injection System

  • Strip the original throttle body and intake manifold from your engine. If it is a carbureted engine, it may be suitable to operate a hydrogen powered engine. One of the problems with hydrogen conversions is the potential for backfiring. Remove any gasoline fuel rails and fuel injectors.

  • Fabricate a fuel rail suitable to carry high-pressure hydrogen gas. Fit the injectors to it. Fabricate adapters to carry the hydrogen from the injector outputs to near the intake valve. Drill and tap ports in the cylinder head or intake manifold near each intake valve and fit them with appropriate pressure fittings. Connect those ports to the injectors using copper or stainless steel tubing.

  • Attach the throttle cable to the new carburetor and adjust the gas pedal travel, as necessary. Modify the throttle position sensor to fit the new carburetor.

  • Fabricate a housing or brackets for the regulators and mount them to the engine block or bulkhead. Connect them to the fuel rail using stainless steel or copper tubing. Install the lower pressure regulator closest to the fuel rail, and the higher pressure regulator further away from the rail -- you can use one very high quality regulator as well.

  • Mount the hydrogen tank in the rear of the vehicle with straps or brackets, and connect it to the fuel regulator using stainless steel or high-pressure copper tubing. You can drill a small hole in an out-of-sight area of the trunk and route the tubing along the undercarriage of the car. You may want to install an electrical shut-off switch for the hydrogen. You will need an electrically actuated high-pressure shut-off valve, and a suitable switch. Install the shut-off valve near the hydrogen tank and mount the switch on or in the dash.

  • Wire the throttle position sensor to the programmable engine control computer.

Modify the Ignition System

  • Remove the distributor. In older models, open the distributor and remove or freeze in place the weights that change ignition timing. In newer model vehicles equipped with plug-on-coil ignition systems, you will have to tune the ignition timing so it does not advance as the engine rpm rise. You may be able to use the vehicle's existing computer.

  • Install the optical sensor in the distributor. In newer models, you may be able to use the input from the crankshaft position sensor or camshaft position sensor. Reinstall the distributor. Mount the engine control computer, and wire the optical sensor to the ECC. Program it to detect when the engine is at top dead center.

  • Program the ignition timing to fire exactly at top dead center. No ignition advance is needed. Wire the engine control computer to the injectors and program it to open the injectors only for the period which the intake valves are open -- this time, in degrees of engine rotation, can be calculated by a careful examination of the schematics of the camshaft and valve lifters -- you need to time the injectors based on input from the crankshaft or camshaft position sensor.

  • Program the engine control computer to open the injectors to their maximum when the engine is at full throttle and to open the injectors the minimum amount when the engine is idling.

  • Turn on the hydrogen fuel supply after your engine is reassembled and program the new engine control computer or existing vehicle computer. You can download or purchase software that will allow you to tune the computer in real time.