Liner Pitting, Dry Fuel & More

2018, Cylinder Liners, Fuel -

Liner Pitting, Dry Fuel & More

As many of you probably know, much of the aromatics, sulfur and paraffin have been removed from today’s diesel fuel and gasoline, making it much “drier” fuel than it used to be. To offset this change, Forrest Lucas of Lucas Oil, while recently speaking at a seminar in California, told me that I should be using the Lucas Fuel Conditioner in my gasoline engines and Harley Davidson. Now, I keep the small bottles of this product in the saddle bags of my bike and in the trunk of my car and use it whenever I fill up.

The reason I’m writing about this “dry fuel” issue comes from the recent surge in 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, but 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 a mere 40 millionths. Could it be that today’s diesel fuels do not have enough lubricity for such a tight clearance? I think so.

Since the 1990s, we at Pittsburgh Power have recommended the use of Lucas Fuel Conditioner with each tank of fuel. Usually, the complaint is the price – and my response to that is purchase it in a 55-gallon drum, if you can, and keep it at home to fill your own jugs. We have sold several drums of this product and it drastically lowers the price. Also, the lubricity and the additives in the Lucas Fuel Conditioner will increase the fuel mileage of your truck, offsetting the cost of the product to almost zero (and the injectors in your engine will be more protected). Considering the cost to replace one electronic injector while out on the road, the cost of the Lucas is minimal.

A few years back, after having his Cat engine rebuilt somewhere in Idaho, an owner operator had burned through six sets of injectors. When he called me, I asked him if he had ever tried the Lucas Fuel Conditioner. His answer was, “No, it’s too expensive.” Interesting. So, this owner operator will spend thousands of dollars for multiple sets of injectors, as well as the time and labor to install them, but won’t invest $34.00 for a gallon of Lucas Fuel Conditioner. How am I supposed to help a guy with that attitude and mind-set? Well, I can’t.

Another problem we saw in the shop this week was liner pitting, and this was in 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 now available. But, I do hope the antifreeze manufacturers are using soft water when they mix and bottle the pre-mixed 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 micro-jet shock wave that travels at about 1,250 mph, which eventually causes the pitting.

Bad grounding of the engine to the chassis can also cause liner 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 can 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 develop completely through the liner, combustion will transfer into the radiator, and coolant will begin to seep into the oil when the engine is shut off. Extended-life coolant does not require the DCA additive, but I’m not sure which coolant was in this pitted Detroit engine. I just want you to be aware of the problem.

Back in the days of the Big Cam Cummins, I once saw a liner pit through in 90 days. The upper counter bores were several thousandths out of round, which caused the liner to slap harder against the coolant. Coolant moves slow and the liner vibrations are somewhere around 1,400 mph. To avoid this destructive pitting, I recommend that you know which coolant you have and what water filter it takes, check your DCA levels with the strips, and install good ground straps.

Mechanics are still building engines without checking the liner protrusion! I have discussed this issue many times but checking this measurement and properly setting the liner protrusion is crucial when rebuilding an engine. This is a must-do when installing liners. Low liner protrusion means the head gasket will fail 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 – and, 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, or is there 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 out there, however if the shop isn’t equipped with the proper tools, then the job can’t and won’t be done right.

Please don’t neglect the emissions system on your 2008 and newer engines. The Diesel Force injected foam cleaning machine we are now using is doing a fabulous job of removing the EGR soot from the intake manifold, combustion chambers, turbocharger and EGR valve. Have this cleaning performed and the “Dorothy” soot eater installed, and you’ll run another 250,000 miles almost trouble free. And, if your horsepower is too low or your engine responds too slowly, we can fix that problem, too. Life is too short to drive a weak truck! If you have any comments or questions, I can be reached at Pittsburgh Power in Saxonburg, PA by calling (724) 360-4080.