Now lets discuss generic pistons and compare them to Cummins pistons. The following information is taken from a metallurgical engineering report.

The three pistons that were tested were Sealed Power, Perfect Circle and AEPP or Associated Engineering. Here are the results of the tests:

#1: The three pistons were manufactured from a Hypereutectic aluminum silicone alloy while the Cummins piston is make from a eutectic alloy, which is higher in silicone and nickel. The silicon and nickel give the piston higher temperature stability. In other words, when you're pulling a mountain and your pistons are hot the Cummins piston will not grow as much as the other three. Your chances of scoring a liner are less with genuine pistons.

#2: All three of the generic pistons were at the bottom of the scale for hardness and tensile strength. This means that the pistons will crack in the wrist pin area sooner than genuine Cummins pistons.

#3: FE, which stands for iron is present in the generic pistons and this reduces the ductility and tensile strength and has a significant effect on the fatigue and thermal fatigue performance of the piston.

My feelings on generic parts are as follows: Cummins engine company employs over 16,000 people. Many of which do research and testing. The amount of money spent each year on engineering and testing is astronomical. Take a tour of the testing facility in Columbus, Indiana and you will see what I'm referring to. This testing must be done in order to improve the engine. Remember that 10 to 15 years ago, if your engine ran 300,000 miles between overhauls, you were elated. Now 750,000 miles are expected before the first in chassis rebuild. That's progress. In fact, some of the STC engines have reached 1 million miles without a rebuild. In order to keep the progress going the engine company has to make a profit and that comes from the sale of parts, genuine Cummins parts. Let Sealed Power, Clevite, Perfect Circle and AEPP manufacture gasoline engine parts. That's where they spend their engineering money. Not on diesels.

Now we're going to discuss the fleet engines of CPL 838 and 840. They are supposed to be 315 and 350 horsepower, if you're lucky. These engines, in stock form, are very sluggish. They were never meant to be driven by owner-operators. However, when these fleet trucks are sold, owner-operators buy them. Now we have the problem of trying to make a fleet engine perform up to the standards of owner-operators. The main problem with this engine is the high-compression piston, which is 17.0 total. The timing is set at .101 and the camshaft is not used in any other engine. The first time I looked at this engine I thought Cummins engineers made a mistake.

Abdul Kahn was the first person to bring one of these lemons to our shop to be rebuilt. Naturally, he wanted horsepower. We change the pistons to a different compression ratio, change the timing, turbo, injectors and fuel pump. Our goal was to take a CPL of 840 and build a high-horsepower engine that didn't smoke when it was cold because Abdul lives in New York City. We obtained our goal and Mr. Kahn is happy with his engine.

Next, we got a call from Bill Price in Phoenix, Arizona, who happens to have a fleet of CPL 838, 315 h.p. His engine does not use oil and has no blowby. Naturally, he wanted to build horsepower using fuel only. We built Bill a set of injectors going two sizes larger than stock. We installed a liquid fuel pressure gauge and increased the flow from the fuel pump by 25%. This fleet NTC 315 came to life in a huge way. It eats 425 Cats, 444 Cummins and chases his friend, John Albu's, hot NTC 475 twin-turbo from Phoenix to Los Angeles and back. How long is Bill Price's engine going to last? Who knows. It depends on Bill's right foot. So far, it has lived 8 months longer than I thought it would. He asked for power and we gave him power. Since Bill's truck runs so strong we have cut the injectors back to one size larger than stock and still we have fantastic results from these fleet engines.

Last week we installed one size larger injectors in John Farley's NTC 350, CPL 840, T600 KW and set up the pump 25% to feed the larger injectors. Now John drives a beast. John left our shop and went to New Bethlehem, PA to load 48,000 lbs. of brick. Once on exit 13 on I-80 going towards Ohio he never came out of 9th over. John called us from Ohio and told us how shocked he was at how his fleet lemon now runs.

If you own an 838 or 840 CPL engine be very careful when doing an overhaul.  We have had many customers try to reconfigure this engine themselves and end up mixing in the wrong parts.  This is a dangerous situation and major engine failure is the result.  Also, a lot of customers are taking they're STC engines and are trying to convert them to fixed time engines.  This is a very poor practice.  The result is shortened engine life and less power.  Again, a mismatch of parts is possible and severe engine damage can be the result.

If you're looking for a used truck, find one with an STC Cummins engine, bring it to Pittsburgh, and we'll put a smile on your face every time you see a mountain with a Cat or Bulldog pawing their way up the right lane. By the way, the left lane is no longer the Monfort lane, it's the Cummins lane.

Diesel Injection is now the proud owner of a 1995 club cab 4X4 Dodge Cummins pickup. This beautiful new truck had 17 miles on the odometer when we started making changes to the engine (for more performance, of course). On a 14% grade the 95 Dodge was 19 mph slower than our 89 Cummins Dodge although the 95 model cost almost twice as much as the 89. More money and less power. I definitely do not agree with this sort of deal. The changes have been made to the injection pump and the exhaust system. Next is the turbo and nozzles. When we're finished, the horsepower will be around 250 with 650 lbs. of torque.  We will keep you posted as to the outcome of this great truck.

On February 20, 1995, an N-14 430 h.p. mechanical Cummins engine is coming to our shop for a moderate horsepower increase. We will convert this N-14 to 600 horsepower. It will be interesting to see of we can hold this great engine back to 600 h.p. after our modifications are made.

The next time your engine needs injectors, please call us with several days notice and we will custom build a set of performance Cummins injectors to suit your horsepower requirements. To build horsepower, you must increase the flow and, in certain situations, the cup size of the injector. This is where it all begins; right at the injector tip, not at the fuel pump. If you're rebuilding the engine, lower the compression ratio and retard the timing. This will help produce horsepower and it is easier on the engine. With our ceramic pistons, retarded timing locked in, mapwidth enhanced turbo, and injectors two sizes larger, you can have a great running high performance engine.

Which cylinder heads do we use and recommend? We recommend the Cummins Premium Gold head with a two-year, 200,000-mi. warranty. Yes, the head costs more, but we have never had a failure with them and the warranty is outstanding.

Do we port and polish the heads? No. However, you can do yours and it's certainly worth the effort. If you have a die grinder and spare time you will be able to do a first-class job. Start with an old scrap head and cut it apart on a band saw so that you can see where the excess metal is and how much metal can be removed. If you visit your local automotive performance shop with the cut up head, I'm sure they will give you some assistance. Please keep in mind that the Cummins head was designed back in the 50's when there weren't any turbochargers. Back then they were happy with 200 h.p. Now we're building 800 h.p. and the head hasn't changed much. With four times the h.p, we need four times the air. So, please take time to port your heads. Our local speed shop will do it for you. However, it is expensive because time is money.

Remember, on a gasoline engine, horsepower is made in the heads. On a diesel engine, a good porting job will lower your pyrometer and enable your engine to run more efficiently.

At this time I would like to address an issue that has been bothering me for quite some time. It's the fact that people call us for free information such as part numbers and specifications. I have spent twenty two years developing the NTC 855 cu. in. Cummins engine. If you're interested in building your engine to our specs, please have the decency to purchase the parts from us. We will be happy to give you the specs for free. After all, how many loads of freight can you haul without being paid? We do not charge for our time on the phone, but we need to be paid the same as you do. If you want a great running engine at least purchase the parts from us and we will be here to service you years from now.

Pistons: Don't put 300 or 350 pistons back into your NTC 300 or 350 h.p. engine if you want performance. The compression ratio is too high. You can put 400 pistons in an NTC 300 (certain CPL’S) even if you're not going to change the timing. Change the injectors to one size larger to compensate for the lower compression piston and your 300 engine will jump to 350 or more horsepower right now, and you will feel the difference. Our high performance ceramic and teflon coated pistons cost $358.50 extra for the coatings. That is the best money you can spend on your engine to increase the life of the piston. Lets face it, the longer the piston stays together, the more miles you will run between engine rebuilds. If you have an NTC 290 or 300 engine and install our ceramic pistons and high flow injectors, your horsepower will be around 375 and that's leaving the cam timing alone. Retard the timing and change the turbo and you now have 450 h.p. Build the proper foundation and you will build horsepower and torque.

Please be warned, the better your truck runs, the more you'll want to drive and the prouder you'll be of the old horse. Like we used to say back in our racecar days, "If you have no pride in your ride, don't park it outside."

By the way, those of you who have fuel pumps, injectors, and turbo cores that belong to Diesel Injection, please UPS, Fed Ex. or U.S. mail them back to us. We need the cores back to be able to help other owner operators that need horsepower.

The race of the decade took place starting at Dysarts truck stop in Bangor, Maine. Bill Jones with his 1977 K.W. Conventional pulling a tri axle rib sided trailer grossing 104,000 lbs and Lenny McMannus with his 1985 CEO K.W. with a 120" double eagle bunk pulling a 45 tandem aluminum flatbed grossing 82,000 labs. Both trucks have NTC 1000-h.p. twin turbo Cummins engines but Lenny McMannus certainly had the advantage over Bill Jones (higher gears, more speed, less weight and a much more aerodynamic trailer).

As these two high horsepower gentleman pulled out of Dysarts and headed south on I-95 they ran together for the next 185 miles. Bill Jones lead the way and used 300 lbs of fuel on the hills. Lenny McMannus only needed 250 lbs to stay right on Bill's rear. Each engine is capable of 400 lbs. plus fuel pressure and neither driver ran his engine wide open. 1000+ horsepower is excessive and Bill's transmission is only a 12-5-13 speed, and that is holding over 2,600-ft lbs. of torque. Some people say that it can't be done, but Bill's doing it.

There it was 185,000 lbs. of semis traveling south on I-95 with 2,000 h.p. between the two of them. It's a good thing that both drivers are intelligent and levelheaded.

The New England States has yet another 1000 h.p. + twin turbo Cummins which is owned by Vernon Harris of Martha's Vinyard. Also, we better not forget about Ken Hawkin's twin turbo KTA that has approximately 1000 h.p. to the ground.

Onto how to build a high horsepower Cummins engine:

Many people are still playing with the fuel pump to increase power without further modifications of the engine. Do not do this, it will deteriorate your camshaft. You should install our high flow injectors 2 sizes larger, retard the timing, install the liquid filled fuel pressure gauge and, with moderate fuel pressure, the engine will produce 500+ horsepower. If that isn't enough power to satisfy your desires then the next step is ceramic-coated pistons, high lift camshaft and mechanical variable timing.

If you are fortunate enough to own an STC engine (step timing control), then all you need are the high flow injectors, high volume fuel pump, mapwidth enhanced turbo and fuel pressure gauge. You decide what horsepower you want and we'll custom build the fuel system for you. Driving high performance Cummins engines will put a smile on your face. You don't need a new electronic engine to have 500 h.p. All you need is a good fuel system.

Mufflers: We have available high flow low restriction mufflers. They are a straight through design and DOT legal. The diameters are 9" and 10" diameter with 5" inlet and outlet. Your exhaust temperature will be cooler with these mufflers.

I met a lot of owner operators from the western part of this country who are still driving stock engines. I can't imagine how you can drive a truck for thousands of miles that doesn't respond. Dropping gears every time your truck sees a hill is very tiring on your body. Think about this: If you can maintain 10 MPH. faster than you currently do, west coast to east coast is one full day less driving time. So in a round trip you will save two days of driving. That's 20 hours per round that your engine isn't running. Are you going to save fuel? Absolutely, almost 20 hours worth. The greatest advantage is the pleasure of driving a good running engine and two more days at home. This pertains to those of you who are driving stock 290, 300, 315 and 350 horsepower engines. To convert these engines to higher horsepower all it takes is a set of high flow injectors and a liquid filled fuel pressure gauge kit.

Many times we are asked the question of how does the transmission and rear ends handle the 2,200 to 2,500 foot pounds of torque our engines produce. The answer is, you must have a light foot and be gentle with the throttle. When you're in the low side of the transmission you don't even think about standing on the throttle. Think about how a thoroughbred horse is treated when he wins a race. They put him on display, take his picture, pet him, and cover him with a blanket.

If we build an engine for you it will be a thoroughbred and it will be the fastest truck up the mountain. How would you treat it? When you walk out of the truck stop and look across the parking lot at all of the trucks lined up you will know that yours is the most powerful of them all and you will be smiling on the inside as you head toward your beast. The best part is when you come to the mountain. You are the king of the hill!