17th August 2021

Could classic cars have a hydrogen future?

Battery electric vehicles might have grabbed the headlines more than any other new-energy technology, but Hydrogen is hot on its heels. Could classic cars have a hydrogen future? We take a closer look.

On a recent trip to JCB’s R&D facility, Footman James ambassador Harry Metcalfe discovered that the company has been developing combustion engines that run purely on hydrogen - without a fuel cell in sight.

“It’s not internal combustion that’s the problem, it’s fossil fuels,” said JCB Chairman Lord Bamford, before going on to explain that by adapting traditional piston engines to run on hydrogen, the industry’s hundred years of experience could be used to deliver zero CO2 emissions now.

A typical 20-ton excavator would need eight tons of batteries to run on electric power alone, at which point the machine would have to be made stronger – and therefore heavier – to cope with the increased weight. A hydrogen fuel cell-powered excavator, meanwhile, would weigh far less but would become prohibitively expensive, at more than double the price.

But as Paul McCarthy, JCB’s chief powertrain engineer explained, by converting their diesel engine from compression to spark ignition with a cylinder head specially adapted for hydrogen, they were able to preserve the low-end torque characteristics their machines require while emitting zero CO2 and only the occasional puff of water vapour during a cold start.

British firm ULEMCo has developed a dual-fuel system for commercial vehicles - such as refuse trucks - that works by injecting hydrogen into the combustion stream during certain operating conditions, displacing up to 70% of diesel and reducing tailpipe emissions as a result.

Unfortunately, converting your classic car to run on hydrogen isn’t as easy as it may sound... Hydrogen has key differences in its combustion properties, most notably that it burns with a much faster flame front than a traditional petrol/air mix. That can lead to backfires as the combustion wave travels back beyond the intake valve, while its lower ignition energy can result in pre-ignition and knock.

Tempting as it might be to recreate the infamous wartime ‘gas bag’ vehicles, for now, it’s best left to the professionals.

Would you ever consider converting your classic to run on alternative fuels? Let us know in the comments below...

Yes, I would consider conversion. The main problem as I see it at present is how to store Hydrogen on the vehicle? Hydrogen as a compressed gas is usually supplied in high pressure (200bar) cylinders. When is used, the gas pressure is reduced by a regulator connected to the cylinder. Having high-pressure cylinders on vehicles brings all sorts of problems not the least of which is compliance with the current laws on transporting pressurised flammable gasses. By contrast, LPG (Liquid Petroleum Gas) is stored and delivered in its liquid form and has a significantly lower storage pressure which varies according to ambient temperature and has a storage pressure of about 20bar, which is about 10 times less than Hydrogen, it is also approved for use in vehicles. Although less polluting, it still gives off pollutants when burned and is a fossil fuel. Therefore, we should look for alternatives without totally ruining the vehicle and making it something which it is not. If we converted the vehicle to say electric, it would probably mean the removal of the engine and gearbox and replacement with new components and a battery, thus, making the vehicle into something considerably different from the original and no longer a historic vehicle apart from its outer appearance.

Tetley, 21/08/2021

Yes! But I agree that in twenty years time we will look back at all those battery operated cars and say ‘what was that all about then! We have yet to assess the environmental damage of disposal of old batteries. There has to be an eco-friendly alternative to fossil fuels. Is the great-grandson of my grandfather's walking buddy, Cyril Bamford, going to come up with the answer. Maybe not quite yet!

Crisp, 21/08/2021

Would be interesting to see what exhaust note is achieved with a hydrogen combustion conversion. Whilst an EV conversion of a classic vehicle might deliver green propulsion I can't help but feel it takes away some of the emotional connection by stripping away the noise. Hydrogen combustion feels like it has a greater potential to replicate a more authentic experience, whilst potentially achieving big savings for the environment. Also, surely it would be cheaper to replace the heads and fuel system of a vehicle than retrofit an EV motor and battery packs? Fingers crossed the government and other industry investments will yield some results.

Dr Mcr, 17/08/2021