Common rail fuel injectors are becoming the go-to choice for manufacturers of heavy-duty diesel engines. DFI gets asked all the time about the difference between common rail and traditional EUI mechanical injection system injectors.
This post is dedicated to helping you understand the difference between the two and why they are used in certain engines and not others. We are going to be using the Series 50/60 and DD15/16 diesel fuel injectors as an example.
As the oldest of the two series featured in this post, the Detroit Diesel series 60 injectors were used in several applications from 1987-2011. Compared to previous injectors, the series 60 Detroit Diesel injectors brought with it many improvements such as more power, increased fuel efficiency, and reduced noise/vibration. But like with most technology, it did eventually get phased out by more modern EUI injectors.
Although EUI injectors are superior, they aren’t without their faults. They have more parts and therefore more components prone to failure. A camshaft activates the fuel pump which in turn creates the required pressure for the injector. The six rollers, rocker levers, and rocker shafts are all parts needed to deliver fuel.
Additionally, the camshaft timing is not variable in these models. What does this mean? It means that fuel injection pressure is directly affected by the speed of the engine. Also, the loss of pressure after each firing reduces combustion efficiency.
As a result, soot and particulates get deposited inside the engine. The high-pressure solenoid is controlled by the ECU to adjust the timing and injection but is nowhere nearly as adaptable as a common rail injection system.
Highway & Heavy Parts has put together a great article about the Detroit Diesel Series 60 diesel engine. Check it out here!
Even though the DD15/16 was around for only 3 years (2007-2010), it made a big splash in the commercial diesel engine world. It was the first manufacturer to use a common rail fuel injection system in this field. The system was made up of a high-pressure pump, injectors, a rail, and an electronic control unit. A simple, yet effective system, it promised to overcome many of the previous EUI systems.
A straightforward approach ultimately means fewer failing parts. Unlike previous systems, the DD15/16 didn’t require a camshaft to activate the common rail fuel injector.
On top of that, the high-pressure pump used will tend to eliminate general wear and tear inside the engine. Fuel is delivered to the injectors via a high-pressure rail measuring upwards of 40,000 psi. This high-pressure system is engineered to deliver instant injection and faster injection thanks to a finer spray of atomized fuel.
The ECU can provide created control over both fuel volume and injection timing by having the injectors and pump working in parallel. A multi-fire injection capability allows the common rail system to fire several times during a cycle. This all adds up to a cleaner, quieter burn. It can generate up to five injections of fuel per cycle, making it much more advanced than anything else previously available.
Small details such as multi-fire injection capability made the Detroit Diesel DD15/16 injector extremely advanced and superior in most other ways. It is one of the main reasons that we only sell high-quality parts from the most trusted names in the industry. To find more questions about common fuel system questions, be sure to read our blog post here.
As previously mentioned, engines like the Detroit Diesel Series 60 use a camshaft to inject fuel. To achieve this, several moving parts must work perfectly in sync. The DD15/16 series engine on the other hand used a common rail system, which has far fewer moving parts.
Some common advantages of a common rail fuel system include:
To sum it up, a common rail fuel injection system is virtually superior to EUI systems in virtually all aspects. Having a simpler, more efficient fuel delivery method all adds up to being more durable and easier to fix in the long run. We have a post here that outlines the differences between common rail and unit injectors.
DFI prides itself in being an industry leader when it comes to selling genuine Bosch EUI and common rail fuel injectors for Detroit Diesel engines. Every single injector that leaves our shop is guaranteed to meet or exceed OE specs. The best part is that most injectors will cost you 50% less than an OEM manufacturer would charge.
All fuel injectors come with a 1-Year Unlimited Mileage Warranty. If that’s not a good deal, we don’t know what is!
Do you have any questions regarding DD15/16 or 50/60 series fuel injectors? Our ASE-certified staff would be more than happy to answer them. Give us a call at (855) 212-3063. Our ASE-certified staff is extremely knowledgeable and will be more than happy to get to the bottom of your concerns.
