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...

I would pay to have this professionally done for my entire fleet of classics.

Bangering on, 02/01/2022

Hopefully, soon there may be the possibility of storing hydrogen as a liquid and at low pressure as some form of hydride that is weakly bonded so that the hydrogen is easily recoverable through heat. I believe that some some companies are making great progress on that front and may have already developed conversions using that technology. If we could fill up with hydrogen then yeah, I would get my old car converted for sure. As Retro (above) said, with a standard conversion NOx would still be generated but I believe that would be in massively lower amounts than with standard combustion. Additionally diesel vehicles could be made much cleaner with greater economy if some hydrogen/oxygen mix was injected into their cylinders. Again there are a handful of companies that can do this. Personally I think that hydrogen should be given much more consideration and gov't interest as a piecemeal solution because if we can convert or clean up those millions of older vehicles then we could run them into the ground for the coming years and after move to electric.

Mike, 14/11/2021

Definitely interested in hydrogen combustion as an alternative to converting my classic car to electric when environmental legislation eventually forces hydrocarbon/fossil fuel guzzlers off the road. To be truly pollutant free, however, we will need 2 compressed gas tanks: one for hydrogen, one for oxygen (or a mix if that is possible). Otherwise there will be harmful nitrogen byproducts in the exhaust, from burning hydrogen with air (noting that air is mostly nitrogen). The Japanese are already safely installing compressed gas tanks on their fuel cell vehicles so half the work is done. We just need someone to design the metering / manifold kit - and an idea about how to refill the bottles! I would happily take a reduced-range option if it means being able to keep my car (and it’s classic combustion sound) on the road.

Retrol Head, 31/10/2021