JCB Loadall engine sizes

In 2005 JCB had developed and finally launched their own engine the Dieselmax. This was a tier 2, 4 cylinder, 4.4 litre engine hence it has the name the triple 4 (444) engine. This launch coincided with a number change on the models, the new models were the 531,536, 541 and 535. The 1 at the end of the 531 and 541 shows the slight uplift in capacity and signifies the next gen model. As before they were 530 and 540 models running with a Perkins engine.

This engine from its first introduction has had two levels of horsepower within the agricultural side of the market. It was soon expanded to thee three levels of horsepower we have today. The lower end is 109 horsepower, this was for the agri models, then the 125 horsepower which was an option on the agri plus but standard on the Agri Super and then finally on the Agri Super you could pay for an upgrade to 145 Horsepower. This final upgrade was actually done by a slightly larger head, so actually the 145hp engine was now a 4.8 litre.

Over the years there has been many upgrades to engine technology and JCB has pretty much used them all.

The JCB dieselmax engine started life as a tier 2 mode, that is pretty much rotary fuel injection pump, traditional cheap injectors, standard turbo, standard baffled exhaust (no special elements inside) the most advanced part was maybe the intercooler to cool the air into the engine so it burns better.

Going from tier 2 to tier 3 in 2008 was the integration of common rail technology – where the injectors did all the hard work and fired when the ECU told them. This allowed far higher pressures and better burn, but yes, you guessed it, far greater injector and pump cost. Although as a slight benefit they could be diagnosed with a computer far more accurately.

As we got to Tier 4 interim around 2014 (shark fin bonnet and cab upgrade), next to be upgraded was the turbo, along with the name going from Dieselmax to Ecomax. Long gone was the cheap simple one, it was replaced by a VGT (variable geometry turbo) it even had its own ECU attached to it, and a price tag to match. Luckily they are actually very reliable and don’t cause a lot of problems. With Tier 4 interim also came the introduction of EGR (Exhaust gas recirculation) this is where a small amount of gas is diverted through a cooler and back into the burn chamber to act as an inert gas, bringing down the temperature in the chamber and making it produce less nitrous oxide. NOx. We also cant forget the catalytic converter style exhaust which gets rid of some final emissions before being released into the world.

Tier 4 final in 2016 is where things get really complicated, not only have we still got the common rail, the EGR, VGT and the catalytic converter, we now have the addition of a fans favourite….Adblue. As with everything above 74 horsepower in 2016 Adblue was introduced as a way of controlling emissions. The tank is hidden within the fuel tank on the other side and piped across to be injected near the exhaust. This is all squeezed in and around that catalytic converter which is still needed.This all makes for a rather full engine bay, which is actually pretty much the same size as back in 2006!​

At Thorncliffs we see the main demand for Loadalls being the Agri Super with 145hp. The extra horsepower is always used on a farm where the machine is expected to be lifting a big capacity bucket, whilst crowding forward, booming out and driving at the same time. Being able to do all these things at the same time with plenty of power means that residuals on these machines stay high and you can easily recoup the £1000 option at purchase for the extra 20 horsepower.

Tier 5 will be the next stage for the engine however that should be a year or two away, hopefully! One thing is certain, that everybody is hoping for even more power. However this could come with even more technology and potential problems. The 444 engine has always been a very reliable, economical and powerful unit, lets hope it stays that way.