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High Performance Diesel Engines

By Bruce Mallinson

July, 2018

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Dry diesel fuel, many of you know that twice the aromatics, sulphur, and paraffin have been removed from today’s diesel fuel and gasoline. Forrest Lucas of Lucas Oil and I were speaking at a seminar in California and he told me that I should be using the Lucas Fuel Conditioner in my gasoline engines and Harley Davidson. I try to remember to do so, I keep the small bottles of Lucas in the saddle bags of the bike and in my car. The reason I’m writing about this is the popularity of the older N-14 Cummins engines. Many times a week we get phone calls about injectors failing in this great engine. This is just my thought, the original design of the N-14 injector was prior to the government mandating low sulfur fuel, and the clearance in a barrel and plunger of an injector is 40 millionths. Could it be that today’s diesel fuels do not have enough lubricity for such a tight clearance? We have recommended since the mid 1990’s to use Lucas Fuel Conditioner with each tank of fuel. The complaint is the price of the Lucas, and my response to that is purchase it in a 55-gallon drum, keep it at home and fill your own jugs. We have sold several drums and it drastically lowers the price. The lubricity and the additives in the Lucas Fuel Conditioner will increase the fuel mileage and now the cost is zero and the injectors are protected. Considering the cost to replace one electronic injector out on the road, the cost of Lucas is minimal. A few years back an owner-operator recently had his Caterpillar engine rebuilt somewhere in Idaho and has burned through 6 sets of injectors. I asked him if he tried Lucas Fuel Conditioner, his answer was it’s too expensive. Interesting, he will spend money for 6 sets of injectors, the time and labor to install them, but won’t spend $34.00 for a gallon of Lucas, how am I supposed to help a guy with that attitude?

Another problem we have in the shop this week is liner pitting and this was on a 60 Series Detroit. Several years ago, I wrote about this very subject, and I felt it was a problem of the past with pre-mixed coolant, I hope the antifreeze manufacturers are using soft water when they mix and bottle the coolant. Liner pitting is caused by the vibrations created when the injector fires and the piston is forced down the liner. Bubbles form on the outside of the liner and they implode by the movement of the liner. Implode means they are crushed inward and this sets up a microjet shock wave that travels at about 1250 mph. Bad grounding of the engine to the chassis can also cause this pitting. It’s always a good practice to install a few ground straps from the engine to the chassis and the cab to the chassis. Bad grounds create a lot of other problems too. Water filters contain DCA which keeps the water in the coolant soft and is meant to eliminate liner pitting. You don’t want this problem, once the pitting is eroded away at the liner a small hole will go completely through the liner and combustion will transfer into the radiator and coolant will seep into the oil when the engine is shut off. Extended life coolant does not require the DCA additive and I’m not sure which coolant was in this Detroit engine. I just want you to be aware of the problem. Back in the days of the Big Cam Cummins engines I saw a liner pit through in 90 days, the upper counter bores were several thousandths out of round thus allowing the liner to slap harder against the coolant. Coolant moves slow and the liner vibrations is somewhere around 1400 mph. Know which coolant you have, what water filter it takes, check you DCA levels with the strips, and install ground straps.

Liner Protrusion: Mechanics are still building engines without checking liner protrusion, this is a must do when installing liners. Low liner protrusion means the head gasket will pail prematurely. There is no repair that can solve this problem other than removing the liners and cutting the upper counter bore for liner shims. Ask your mechanic if he has a liner protrusion gauge, if in doubt ask him to show it to you. If he has the gauge, does he have the tool to cut the counter bores, and does he have another shop in your area that can travel to his shop to cut the counter bores. If the answers are no, you better tow your truck to a shop that is equipped to do the job correctly. There are many great mechanics, however if the shop isn’t equipped with the proper tools, then the job can’t be done correctly.

Please don’t neglect the emissions system on your 2008 and newer engines. The Diesel Force injected foam cleaning machine is doing a fabulous job on removing the EGR soot from the intake manifold, combustion chambers, turbocharger, and the EGR valve. Have the cleaning performed and the “Dorothy” soot eater installed, and you’ll run another 250,000 miles almost trouble free. Horsepower is too low; the engine responds too slowly; our electrical department can fix that problem too.

Life is too short to drive weak trucks!

Written by; Bruce Mallinson, Pittsburgh Power Inc.,
3600 S. Noah Drive, Saxonburg, PA 16056
Phone 724-360-4080
Website: Pittsburghpower.com