8. Horsepower and Torque: 3406B and 3406C

Words and thoughts from the man who started it all.

8. Horsepower and Torque: 3406B and 3406C

Postby Fernando on June 1st, 2009, 1:35 pm

Here we go writing about something I said that I would never write about, Caterpillar engines. We do have the genuine Caterpillar cylinder kits available in ceramic and teflon just like the Cummins cylinder kit. If you're interested in Cat ceramic-coated pistons please allow at least three weeks for delivery.

What we do have readily available is a high performance high output mapwidth enhanced turbocharger that will increase the manifold pressure by 5 pounds of boost and lower the exhaust gas temperature by approximately 100 degrees.

This increase in manifold pressure is obtained on a stock 3406 B air to air engine. If the fuel is increased the boost will greatly increase. My understanding of the stock turbo on these engines is that they are almost inadequate for 425 H.P. at sea level let alone at high altitude. It always amazes me at how many trucks running across the Rocky Mountains at 1100 degrees exhaust gas temperature on the cold side. On the hot side, that equates to 1400 degrees. Keep in mind that aluminum melts at 1350 degrees. Thank goodness for oil cooling nozzles or you would not be able to cross the mountains.

High flow Caterpillar nozzles are the next item you need to produce horsepower from your 3406 B&C engine. Our nozzles are available from 10% to 40% more flow. You decide what you want and we’ll build them for you and they will have warranty in case one should fail. Please keep in mind that we use all genuine Cat parts. We also increase the pop off pressure to clean up the black smoke and bring the injection timing back into specification. Did you ever wonder why a 425 Cat smokes when you increase the fuel delivery at the pump? Its because as the amount of fuel being pumped through the nozzles increases the nozzle opens sooner and closes later than it was designed for and the timing is being advanced with the nozzle opening sooner. As we all know advanced timing is bad for high horsepower diesels regardless of whose name is on the valve cover. With the pop off pressure increased the nozzle opens at the proper time and closes sooner also. This is why Cummins went to the big cam engine in 1978 to inject more fuel over a shorter period of time and with the Cat fuel system you want to obtain more fuel being delivered through the nozzle but at the same millisecond as the stock engine. By increasing the flow through the nozzle tip and increasing the pop off pressure we can obtain this. If you're interested in these high performance nozzles please allow three weeks delivery.

RESTRICTION: It will rob your engine of power. Whether it's an air, water, exhaust or fuel restriction. We are going to address the area of fuel restriction. In previous articles we talked about the advantages of replacing the standard number ten fuel suction hose from the fuel tank to the fuel pump with number twelve hose. The engine will perform better with less pressure from your right foot on the accelerator. When making this change, remove the existing hose and fittings and take them to your local Stratoflex dealer so that he will be able to supply you with the proper fittings. We also suggest the large Cummins spin on fuel filter designed for the 1710 cu. inch V-12 engine. This filter and remote mount base is very economical and will easily run for 30,000 miles before requiring a change. If your truck is equipped with a fuel filter restriction gauge you could possibly run this Fleetguard filter for 60,000 miles. The remote mount base will accept number twelve Stratoflex fittings and you conveniently mount this filter along the frame rails where a fuel filter should be. When you think about how many times you had to change the fuel filter late at night along side the interstate this conversion becomes very cost effective.

This large filter will reduce fuel restriction to the fuel pump and the engine will perform better and run smoother. The price of the filter and base is $44.78. The fuel filter, when its due for a change, is $16.27 and is available at any Cummins distributor. By the way, we always use genuine Fleetguard filters on our Cummins engines because Cummins owns Fleetguard and if there is ever a filter related problem you are covered by a very good warranty. I know a gentleman that had a brand X oil filter disintegrate and pollute the oil system on a V-12 in a drag line which resulted in spun bearings. The reply he received from the filter manufacturer was, we’re sorry for any inconvenience our filter may have caused you however, we feel that we are not responsible for the spun main bearings in your engine. Since that experience there has only been Fleetguard filters on my Cummins and Nissan filters on my wife’s Maxima.

Cost Effective: How many times have you heard this since the recession of 1983. Every company wants everything to be cost effective. My personal feelings are, I could care less, especially when it pertains to my vehicles. If the item that I’m going to purchase will increase performance, improve handling, increase longevity, look good or make me feel better about what I’m doing, then that is good enough for me. Cost effective takes the enjoyment out of life and I’m only here for a short time. Think about every dollar that you spend and you’ll realize that the majority of the money you spent in your lifetime was not cost effective. When your time on this earth has come to an end will you be able to look back over the years and say to yourself that you’ve enjoyed it?

Now here is a cost-effective log hauling Kenworth built by Leroy Cuttler and Marvin Hamilton. This is a man on a mission who must thoroughly love his work. After all, how many men take the time to maintain an older truck let alone build a twin turbo 1000+ horsepower KTTA Cummins just to haul logs? It doesn’t matter what you haul, it's how you arrived! Leroy’s truck is a 1978 A model with an 18 speed transmission. We will feature this truck again after we get to talk to Leroy.

Turbo Boots: What are they and why do they work. Why does keeping your exhaust system insulated allow for a cooler running engine? We all should know that restriction in the exhaust system will rob the engine of performance but why do we want to keep the turbine housing and exhaust pipes insulated? After we realized the benefits of insulating the turbine housing we were informed that we should wrap the first three feet of exhaust pipe from the turbo. Well, that seemed simple enough to us and we’ll always try anything that will enhance performance without sacrificing engine life or fuel mileage. So we ordered a box of header wrap and on the end of the box was a paragraph titled, "How does it work"? One thing that is commonly overlooked by most racers is the matter of heat retention in the exhaust pipes. We have to remember that as soon as the combusted gasses leave the combustion chamber they start to cool down. As they cool they lose velocity and the scavenging effect is reduced. If the temperature of the gasses inside the pipes is kept as high as possible the net effect will be greater velocity, greater pressure drop in the system and higher efficiency. Very recently we have experimented with heat retention materials to improve the efficiency of exhaust systems. These shields retain heat in the exhaust pipes so the exhaust velocity remains very high. This will improve the scavenging effect. This is from Smokey Yunick’s Chevy engine guide in Hot Rod magazine’s high performance series. For those of you who were hot rodders from the 60’s and 70’s you must recognize the name Smokey Yunick.

More on exhaust systems: We recently rebuilt a CPL 1211 NTC 365 H.P. into a 700+ H.P. STC engine. This International was equipped with one straight through muffler so we thought that it would be OK. The story we hear all the time is "I only have one turbo and one pipe coming off the turbo why do I need two mufflers?

Here’s why: With this particular International we installed our manometer to check the backpressure in the exhaust system. Using 1/2 of the fuel pressure available or 150 lbs. we had 40 inches of backpressure in the exhaust system. This was far too much. So we installed a second pipe with a KTA 600 straight through muffler and, on the next test ride using all 300 pounds of fuel pressure, we had only 8 inches of back pressure. That's an incredible drop for the addition of one more muffler and pipe. When the exhaust gasses are released into the exhaust pipe they immediately start to cool causing the density of the gasses to increase. Increased density means slower movement through the exhaust system. This causes the pistons to work harder to push the gasses through the mufflers and causes horsepower loss.

Another owner operator with an NTC 350 slightly turned up installed a dual 6" exhaust system on his truck and informed us that he gained 1/2 gear on the hills with a 13 speed transmission. One half gear increase is about 25 horsepower. If he installs our dual fuel line kit he will gain another 1/2 gear or another 25 horsepower without touching his fuel pump or injectors. You see, building performance from an engine requires more than just turning the fuel to it. If your engine continues to gain horsepower without increasing fuel delivery what do you think is going to happen to the fuel mileage? Also do you think that you’re going to enjoy driving this engine more? Remember the old saying: "Getting there is half the fun". Well in trucking getting there is all of the fun unless of course you enjoy loading and unloading your trailer. With a high performance engine your driving pleasure will be enhanced and you’ll enjoy your work much more and have more pride in your ride.

Speaking of pride in their ride and appearance take a close look at Ron Kelsey of Peoria AZ. and his beautiful 1981 Peterbilt with 2,225,000 total miles. This truck is gorgeous and is equipped with a NTC Big Cam II 700+ horsepower Cummins engine built by Buffington’s Diesel in Phoenix AZ. using Diesel Injection Of Pittsburgh high performance genuine Cummins engine parts. The 700 H.P. is routed through a 6X4 Spicer transmission both with overdrive and then onto a set of 3:90 Rockwell rears. This Pete is equipped with 11.25X5 rubber and has an estimated top speed of 120 MPH. At 1900 RPM the speedometer is pegged at 100 MPH. Exhaust back pressure? There isn’t any because of straight 6" chrome stacks and dual Vortox 15" diameter 1700 CFM each stainless air cleaners. Needless to say this great running Cummins gets plenty of air to breathe. Polished dual 160-gallon fuel tanks and a lot of chrome accent the beautiful custom paint job. The paint is Tangelo orange, which is faded to a Wheatland yellow with gold sunrise pearl and is clear coated.

This Ron Kelsey Special truly deserves the title "Large Car". Not only is this beast powerful and fast, she looks great also!

Forget low gears. With today’s engines you don't need low gears to have power on the mountain. Lets take a paragraph and talk about the Dodge Cummins pick up trucks. Many people are buying the 4:10 gear ratio versus the 3:54 gear ratio because they think that the truck will pull well on the hills. And what’s worse is that the incompetent salesman at the Dodge dealership will talk them into the 4:10 gears. With a long stroke in line six-cylinder turbocharged diesel you don’t need low gears for pulling. Keep in mind that many states have a 75-mph. speed limit on the interstates. With the 4:10 gear ratio the engine is way out of the horsepower and torque curve. In fact the governor is starting to cut the power back. With the 3:54 gear ratio at 70 mph is 1800 rpm. and 75 mph. is 2,000 rpm. The perfect rpm for pulling because peak torque is at 1500 rpm. on the "B" engine. I tuned up a 95 Dodge one ton dualie 5 speed manual transmission in Denver this past March and at stock settings the truck empty would only pull 68 mph. on I-70 at the 470 bypass intersection with my foot flat on the floor. This truck has 4:10 gears. After changing the torque plate, turbine housing, installing a turbo boost gauge and pyrometer this same truck held 80 mph. past the 470 bypass and on up the 8% grade into the Rocky mountains without having your foot flat on the floor.

Unless your Dodge is to be used to pull extremely heavy loads and your only going to operate off road or on two lane roads stay away from the 4:10 gear ratio. Low gears are a poor way to substitute for low horsepower.

Even in an 18 wheeler I feel that you're better off pulling the load in direct gear versus overdrive. I like overdrive transmissions but I feel you should be able to cruise along the flats and uphill grades in direct gear. Overdrive is for going down grades, running empty or if you’re going to run in excess of 70 mph. The 13 speed transmission is only 13% overdrive and that’s OK for cruising. Keep in mind that it takes 268 horsepower to maintain 70 mph. on the level pulling a van with no head wind. More horsepower gets to the rear wheels in direct gear.

Air cleaners: If you have an FLD Freightliner and need more air for the engine there is room in front of the steering tire on the right side. Its just a short distance to the turbo from there and we draw air from behind the front spoiler. We use a Farr Ecolite air cleaner that is 1500 CFM and coupled with the stock air cleaner gives the engine about 2700 CFM. Air filter restriction drops to about 2" with this combination.

Marion Robertson of John’s Island, South Carolina was the first owner-operator to try this combination on his Freightliner and we tried it on Chris Vasileff’s 770 H.P. STC Cummins engine.

Freight Rates: This is a subject that I should avoid however you're being raped at 83 cents per mile. Take an average of 2500 miles per week and figure out what it costs you to live each day. My figures are low but this is the minimum it cost you to pull a load across the interstate. At $1.17 per mile go and get a calculator and list every dollar you spend per month on truck payments, fuel, gas for your family, food for you and your family, clothing, insurance, trailer payments, taxes, license plates, tires, oil. Engine, transmission, clutch, and differentials wear out at about 2 cents per mile, drivers wages of only 10 cents per mile, mortgage or rent payment and don’t forget the utilities at home and you’ll find that $1.17 per mile is very low. The average owner-operator being on the road for five days put in 120 hours per week and this doesn’t count working on the truck on Saturday. I may be wrong, if you have some figures of what it cost per mile please mail them to me. Guy Gregg, President of Herb Gregg Trucking from New Kensington, PA, has some detailed figures for his fleet of trucks and next month we will publish his figures.
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