CAT 3116 Performance Upgrade. Can You Make it Better?

CAT engines are among the best in the world. You are guaranteed to enjoy the engine's durability, reliability, and efficiency. But is it always the case? This is the question some people ask themselves whenever they hear stories about the CAT 3116.

In our article today, we take a look at CAT 3116. We explore the engine's performance. Talk on the street is that CAT 3116 performance upgrade is possible and can help improve the engine's overall performance. We investigate to find out whether the upgrade really makes the engine better and whether it's worth it.

Understanding the CAT 3116

CAT 3116 was introduced in the early 90s, replacing the long-serving V8 CAT 3108 engine. The production continued until the late 1990s when the all-powerful CAT 3126 was introduced. The 3116 served as the baseline for CAT's small truck and small machinery engines. It was the first CAT engine to be made using metric units, and this set it apart from the rest of the engines sold by the company at the time.

CAT 3116 is a 6-line diesel engine, making it a 6.6L (402 cu. In) engine even though many refer to it as a 7L. The engine was primarily found in the military and a wide range of GMC vehicles. They were also used to power boats, generators, and all manner of machines. It was a popular engine that could be applied across the board and whose performance and reliability were guaranteed.

The CAT 3116 engine is subdivided into five classes; A, B, C, D, and E. Class A of 3116 which is best suited for lightweight cargo and machinery, makes 205 hp at 2,400 RPM, while the biggest, which is Class E makes 350 hp at 2,800 RPM.

The earlier CAT 3116 was equipped with mechanical unit injectors (MUI), while hydraulic electronic unit injectors (HEUI) were used in later years. This means the MUI injectors use a governor for fuel control instead of a pump, as with the HEUI. Most of the CAT 3116 complaints, especially the MUI option, revolve around fuel delivery, specifically the rack and the governor.

The CAT 3116 engine boasts a simple design that will serve you perfectly fine when well-maintained. The engine gives you a lot of room for improvement and upgrades, especially in the performance areas. Many owners of this engine have managed to tweak their 3116 to get up to horsepower.

CAT 3116 performance upgrade

There are quite a number of components that you can tweak or replace to enhance the performance of the CAT 3116 engine. The use of the engine will partly determine the upgrades you can do. However, the important thing to note about the CAT 3116 upgrade is that it is doable. As mentioned earlier, the rack, which can be problematic, will need to be synced. The transmission, on the other hand, should be tested and verified that it can support the proposed upgrade.

Working on CAT 3116 or any other CAT engine requires special tools, which can be expensive. Moreover, an engine upgrade demands precise measurements, and in many cases, a CAT mechanic is the best bet you can have. However, some mechanics and DIY enthusiasts have managed to hack CAT 3116 performance upgrade.

What parts are changed during the CAT 3116 performance upgrade?

1) The turbocharger

The first option many people consider is turbo upgrade when they think of giving their 3116 more oomph. The 205hp and or the 290hp come with less powerful turbos than the 350hp engine. When you install the turbo meant for the 350hp 3116 or the C7, you will definitely enjoy immense power. However, you will need to adjust other factors, such as the fuel lines and injectors, to allow the engine to accommodate the bigger turbo.

A bigger turbo means more air is pumped into the engine. The fuel lines should also be turned up to balance the air-fuel ratio in the combustion chamber. You can easily add 50 horsepower to your engine by playing around with the turbo. The most common upgrade option people go for is the CAT 3126 turbo though finding the turbo kits can be tough nowadays.

The turbo in your 1993 CAT 3116 is quite inferior to the turbo option of, say, 2020. By simply installing a newer turbo, you enhance the engine's performance. But many mechanics will advise you to retain the stock turbo and adjust other components if you are looking to improve the engine's performance.

2) The injectors

The injectors are another component you should consider upgrading to get more power in your CAT 3116. The 3116 engine has immense potential, and playing around with the injector should give you extra horsepower.

Bigger injectors deliver more fuel, and if you haven't considered all factors at play, you might end up supplying excess fuel to the engine, flooding it. You may also be running rich, and all these problems might not be worth the trouble of replacing the stock injectors in your 3116.

Another trick mechanics use is adjusting the fuel screw in the governor. By turning back the fuel screw, you allow more fuel in the injector hence more power output by the engine.

3) Piston kits

Going through the online forums, you will find people who have upgraded their 3116 using piston kits upgrades. This procedure requires that you increase the bore to enable it to fit a bigger piston head. The expansion of the bore must be done very carefully using the CAT tooling and by a CAT expert.

A piston upgrade in your 3116 means that you have to consider several factors, such as the change in the size of the head gasket. The piston rings must also change to accommodate the expanded piston heads. Other factors to consider are compression and air-fuel intake. 

4) Fuel lines

The more fuel in the combustion, the more the power output. The fuel lines need to be adjusted to meet the engine demand to get more fuel in the combustion chamber. The fuel lines turn up needs to be precise to avoid flooding the engine or making the engine run rich. The fuel lines adjustment is done alongside air intake adjustment to ensure the air-fuel ratio remains balanced.

5) Adjusting the fuel supply in the engine

This procedure also demands some expertise and the use of some special tools. You can start by adjusting the fuel adjustment screw found between the rocker arms. If the screw has never been interfered with, it will be hidden by a metal bracket. You will therefore need to remove the bracket.

The fuel adjustment screw is adjusted using a 2mm key. First, put a pyrometer at the exhaust to help you with the adjustment. Turn the fuel adjustment screw counterclockwise one and a half times for a start and observe the readings on the pyrometer. In most cases, you will need to turn the screw at least twice to get tangible power.

The power your engine gets by adjusting this screw will depend on the trim of your engine. Some CAT 3116 have smaller turbos and different injectors, while others have bigger turbos. It is imperative that you know your engine first before attempting to adjust the screw.

Is CAT 3116 performance upgrade worth the effort?

The CAT 3116 is one of the friendliest engines when it comes to performance upgrades. But it doesn't mean you can get double the horsepower out of the engine. Many people have complained that their FMTVs and other trucks have had a tough time pulling off when loaded. Some drivers report having trouble uphill with this engine, which is why many go out looking for a performance upgrade.

In many cases, a performance upgrade for the CAT 3116 will only require an adjustment of a component rather than a replacement or modification. For example, replacing a perfectly functioning stock turbo may not be practical when you could simply adjust the fuel screw in the injector governor or the one between the rocker frames. Increasing the bores' sizes and replacing the pistons should only be done if you are sure there is no other available option. Sometimes, an upgrade will cost more than replacing the entire engine.

In other instances, proper maintenance of the engine is all that is required to get the perfect power output from your engine. The CAT 3116 is a durable engine that has proven reliable and capable over the years. When the power drops or the performance deteriorates, you don't need to rush for an upgrade first. Maintaining regular engine service and operating the engine safely might be the answer you are looking for.

Conclusion

The CAT 3116 performance upgrades are quite popular mainly because they allow the otherwise timid engine to roar and handle much more than you could think of. But as mentioned above, the trick to getting the best performance upgrade out of your 3116 is understanding your engine thoroughly. Knowing your engine means you will pick the right upgrade to help you solve or handle your specific challenge.