Caterpillars ACERT truck engines; Is it faster? Does it have more power? What is the real purpose behind the twin Turbo’s?
Caterpillars ACERT truck engines; Is it faster? Does it have more power? What is the real purpose behind the twin Turbo’s?
The Cat design of the Acert C14 and C15 engine using two Turbo’s does not necessarily mean more power or a faster truck. The use of two Turbo’s was Caterpillars answer to obtain the emissions standards set forth by the EPA. In reality, the engine no more powerful than the well know 3406. In fact, while talking to many of the drivers now packing the C15 under hood, they complain of increased fuel consumption, less power, more down time, and higher maintenance cost. Not that this engine is any different than the competitors engines, but the two Turbo’s do not make this engine any faster. The actual design was copied from the Cummins 855. Back in the early nineties I saw a cab over come in the shop and it had two Turbo’s attached to it. I can remember all of us standing around it and commenting that this must be some kind of race truck, but later found out it was an experiment to cut down on emissions, and to try and gain economy.
Cummins scraped the idea and moved toward the ISX. In my opinion, a very smart move and one that has put Cummins on top of the reliability category.What the two Turbo’s actually do is to take a small amount of air from the back side of the particulate filter, mix it with cool air from the inlet and put it back into the combustion chamber to be burned a second time. So in reality you are not necessarily getting more boost, you are just mixing air from two sources and trying to cool it more. They are trying to add more cool air into the combustion chamber I the form of boost, but then they cut this boost down by adding intake actuators that electronically control the flow of air. So in one hand they are adding more boost, but on the other hand they are electronically controlling it. The real theory behind this s to make a cleaner running engine that is much different than Mack and Cummins.Another way of looking at this is maintenance cost.
You know what it is to have a turbo go down. You have down time for replacing it. You have the cost of the turbo and possibly cost for damages to the internal parts of the engine that the blown turbo caused. Now multiply that times two. Now truthfully speaking, we have not seen many turbo failures, yet, but put a few thousand more miles on them. I was talking to a driver yesterday and he had just bought an 08 KW with another Cat. He was telling me that he got a million plus miles on his last Cat with little problems. He had a 3406E, one of the last of the good Cat engines. We are seeing a lot of problems with the air piping for the Turbo’s. All those little flex pipes in-between the Turbo’s are beginning to leak. A four inch long flex pipe between the engine and turbo will cost you $200 plus labor to replace. We are also seeing a lot of Intake Valve Actuator failures. This will sound just like a dropped valve, and will make you think you blew an engine, but despite the high cost of this repair, owners are happy the engine doesn’t need an overhaul.
There are also comments from Cat Acert owners that love them and hate them, but realistically, they are not as efficient and do not perform as well as their predecessors, the 3406 series.So the next time you hear someone shout, “Wow, two Turbo’s” you can tell them its not what they think. This is Cats way of trying to clean the exhaust and do it differently than Mack and Cummins. It is obvious they are not doing this competitively. Cat has decided to pull out of the truck engine business. By the year 2010 you will no longer be able to get a Cat engine in your over the road tractor.
