Vertex Engine
August 26, 2024 in Articles, Machinery
Earlier this year there was a discussion on the forum about how many different manufacturers (or brands) had produced engines that were fitted to horticultural machines. The list became long and would have been longer if I hadn’t stopped adding to it.
The forum topic and list can be found here: https://vhgmc.co.uk/forums/topic/engines-brands-manufacturers/
One engine name that didn’t get mentioned or added to the list was Vertex. Internet searches indicate that these engines had a Villiers connection.
The reason that I mention Vertex is that I have been researching Mountfield lawn mowers and these two-stroke engines began to be fitted to a few models in the mid-1970s – Mountfields own literature and price lists show the use of the 4 hp, 2-stroke engines in 1975. Although I have found a brochure showing these Mountfields with the Vertex engines, I’ve yet to find one of the mowers in real life – what happened to them all? If you are someone who owns such a mower and scouring the internet for info, then you have a rare survivor!
In 1977 and while the engines were already being fitted to their mowers, G. D. Mountfield announced they were now taking over production of these engines and would produce them at their Maidenhead premises, they were marketed as ‘All-British Built’. In fact, in 1977 Mountfield advertised for Skilled Production Machinists to start immediately to set up and run the recently-formed Vertex Engine Division at a new production facility being built in Maidenhead – the advertised wage was £4000 plus relocation expenses.
Mountfield were quite upbeat about their engines. Apparently, they had exceptionally high torque over the whole working speed range giving unmatched power. One trade report (AMJ) stated that the engines would be ‘…a welcome replacement to the engines of US and Italian extraction as seen in previous models’. However, people who maintained Vertex engines in their line of work have told me that they weren’t the best!
Classed as medium-sized professional mowers, in the late ’70s, the three models fitted with the Vertex engines were the 18″ M4 Professional, 18″ M4 Power Drive, and the 21″ M6 Power Drive as illustrated. All three machines were fitted with snorkel air cleaners, and polythene grass boxes were optional. In 1975, Mountfield had listed the M6 Power Drive 2-stroke at £177.50 – which was £19 more than the equivalent 4-stroke.
In the early 1980s, the Vertex models were still advertised, but with other new mowers being more important, an always-evolving market, and whatever issues the Vertex engines may have had, they seem to have soon vanished.
One thing is certain: even with relatively modern machines, some do not appear on the scene or on auction websites. Machines don’t have to be old to have disappeared into obscurity leaving only some fleeting bits of literature and adverts behind.
But I do wonder where all the Mountfield Vertex mowers went!
Briefly, there is a huge range of electric mowers. What’s the difference between the Qualcast Concorde RE25X and the RE30X apart from £10.00 ? Or the Flymo Sprinter E25 and E30 ? A brochure would be mighty helpful!
There isn’t a Mountfield electric mower in the bottom right corner of Dickens advert, they may not have been manufacturing them at the time, but their petrol mowers show that the price nearly doubles between the Mountfield Emblem 15″ and the 16″ self propelled with electric start, both with a 3.5hp Tecumseh engine – would that be a premium product at the time? 
