The 6BT Cummins was introduced in 1984 and was used for agricultural equipment. In 1989 Dodge teamed up with Cummins to offer the 5.9L Cummins in their heavy-duty pickup trucks. This quickly became a popular alternative to the large gasoline engines typically found in heavy-duty pickups. Ever since then diesel pickup trucks have become a massive market in the US.

Diesel engines are far better for heavy towing than gasoline engines, which is part of the reason for their massive success in the US truck market. In this short article, we are going to cover everything from engine specifications, real-world applications, and increasing power output.

The 6BT Cummins is a 5.9L inline-6, with an OHV designed. This is somewhat similar to the AMC inline-6 used in Jeep models of the time.

The 6BT has an iron cylinder block, as well as an iron cylinder head. While this makes it extremely heavy, it also makes it extremely strong. Strength is one of the 6BT’s most known features. Many people have pushed them past 1,400 horsepower, and the stock ones can exceed 1,000,000 miles if properly cared for.

One of the best features of the 6BT Cummins is its fully mechanical fuel system. This makes it excellent for an engine swap because there is only a couple of wires needed to make the engine run. But, because of this you can’t just plug a tuner into it and make more horsepower.

6BT Cummins: Tuning Potential
If factory specifications bore you to death as they do to me, then you’ll enjoy this next section. Who cares what the 6BT Cummins was like from the factory, what is it really capable of?

Well from what I can tell from poking around diesel forums, the 6BT’s bottom end is good for about 800 horsepower and 1400+ lb-ft. Anything past that and you’ll need a built bottom end. The transmission will either need a beefy clutch for the manual, or an entire transmission build for the automatic.

How can you easily get power out of your 6BT Cummins?
Since it has a fully mechanical fuel system, getting power out of it requires basically turning up the fuel. This is typically done by grinding down the fuel plate or purchasing a performance fuel plate. The fuel plate controls the flow of diesel to the engine per a given RPM. Bigger fuel injectors are also very important for the 6BT Cummins.

Obviously, the common upgrades like a larger exhaust also help the 6BT gain power.

So overall the 6BT Cummins is an awesome engine. It was the engine that truly made diesel pickups popular in America. The fully mechanical fuel system makes it great for engine swaps, and also makes it extremely reliable. Getting power out of it is as simple as turning up the fuel and bolting on a better turbocharger.

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