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High Performance Diesel Engines

By Bruce Mallinson and Andrew Wilson

July, 2019

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If you build it right, maintain it, it just might last you a lifetime! 25 years ago, a young man from the Allegheny Mountains of Pennsylvania came into my office and said he wanted to spec out a new Marmon tri-axle logging truck that would carry the loader behind the cab. This truck was to be a 25-year-old Nathan Exley’s first new truck. I was 45 years old at the time and had been a Marmon Truck Dealer since 1990. Nathan and I were rookies at building a specialized log truck that will never see a 4-lane highway, all off-road and 2 lane mountain roads. Together we studied all the Marmon specs, Caterpillar engines, Eaton transmissions and Rockwell differentials.

This truck would never see a scale because its only job involved working in the Allegheny mountains north of Pittsburgh hauling logs back to his father’s log mill. With that in mind, we were not concerned with weight, so we started with a double 3/8-inch frame, standard in the industry was a double ¼ -inch frame. The engine was to be a 425-C Caterpillar engine followed up with a 13-speed transmission. The differentials, standard in the industry was 46,000-pound rears, however Nathan and I contacted an engineer at Rockwell and had a lengthy discussion about weight carrying capacity and off-road hauling. As it turned out there are 3 ratings for differentials, off-road, paved road, and turnpike which would be the same as a 4 or 6 lane highway. The difference between 46,000-pound rears and 48,000-pound rears is 35,000-pounds more weight carrying capacity, so we went with the 48,000-pound rears. The 48,000-pound rears have a 19.5 diameter ring gear and the 46,000-pound rear has an 18” diameter ring gear. The suspension was a walking beam which rode on rubber blocks, and now the walking beams ride on Link Mfg. air bags. The front axle is a 20,000- pound Eaton with duel steering boxes. I have no idea of what the empty weight of this heavy-duty Marmon is. Nathan’s friends in the logging industry chastised him and me for building such an overbuilt truck. But here it is, 25 years later, Nathan is still driving his Marmon and his negative friends have been through 5 trucks during this same time period. By the way, this Marmon has the original paint on the cab and hood, aluminum wheels have been replaced, the Caterpillar engine rebuilt a few times, and the 13 speed has been replaced with an 18 speed. Total miles on this beast of a log hauler is 1,807,805 and it has hauled 24,843 loads of logs. 

We’ve been getting a lot of feedback from customers using our Max Mileage Fuel Borne Catalyst and the results are good. We’ve heard many owner-operators tell us they saw decreased DEF usage with the catalyst. We’ve also heard of engines running much smoother, with more power, and more responsiveness. Some owner-operators are even seeing improved fuel mileage. Before we tell you how much their fuel mileage improved, you need to understand that fuel mileage is a very fickle thing. We cannot guarantee any improvement in mileage with this product because fuel mileage depends on so many different variables. However, we have a few owner-operators that have seen over 10% improvement while using the catalyst. The reason for this is improved thermal efficiency that translates into getting more power from every molecule of fuel. Let’s go into more detail…

This is very technical: Let’s start with a standard definition of efficiency. Percent efficiency is calculated at [Output/Input] x 100. The closer the Output comes to matching that of the Input, then the closer to 100% efficient you will be…for anything. In the case of engines, we are talking about the theoretical amount of heat (BTUs) in a gallon of diesel (Input) as compared to the actual amount of heat (BTUs) liberated after the fuel is ignited and that goes to moving the piston during the power-stroke. Any fuel that is still burning when the piston reaches the bottom of the stroke and the exhaust valve opens is wasted heat. That waste heat is doing nothing to help move the truck down the road. The waste heat is reflected in the Exhaust Gas Temperature (EGT) by a pyrometer. Waste heat creates NOx and causes more DEF to be consumed.

•The Fuel Catalyst (FC) accelerates the burn rate of diesel in the piston-cylinder during the power-stroke of the engine.

•About 10% more heat (BTUS) is liberated during the power stroke with the catalyst than without.

•This translates to about 60% lower “engine-out” soot emissions.

•More BTUS are contained in the larger, slower to burn fuel molecules than the smaller, easier to burn molecules.

•The catalyst burns all different shapes and sizes of fuel molecules in the diesel, faster.

•This results in an improvement in the thermal efficiency of any reciprocal internal combustion engine.

•More heat is released earlier on crank angle – more pressure is exerted against the piston, and more work is generated for the same amount of fuel burned with the catalyst than without.

•The more heat (BTUS) from fuel that can be released while the piston is moving, the better. Because that improves thermal efficiency.

•An increase in thermal efficiency is reflected in a lower EGT. This is what our friend Tad Kelsey observed on his EGT Pyrometer. On the flat, with cruise control at 65 MPH, he has 2.5 pounds of boost and his EGT is 200 degrees lower that previous, under the same conditions, without the catalyst. Tad has gained a noticeable increase in fuel economy and uses less DEF because of both of these effects – that is, the improvement in thermal efficiency of his DD15 engine.

•Charlie, the owner of a Paccar engine from NY saw a 1.5 mpg improvement because of this same effect. 

Written by Bruce Mallinson and Andrew Wilson, Pittsburgh Power Inc., 3600 South Noah Dr. Saxonburg, Pa. 16056. Phone 724-360-4080. Website.: PittsburghPower.com