1993/11/29 Caterpillar

Oil Recommendations For The 3500 Family Of Engines{1300}

Usage:

3500 Engine History

Times are continually changing. Part of this change includes demands placed on diesel engines. These demands include things such as higher horsepower to weight ratio, better fuel economy, and lower emissions. To meet these demands, 3500 engines have undergone a series of iron changes. The 3500 engine has evolved through the following three basic "PHASES":

Changes that took place with the two piece pistons (see Chart A) were raising the top ring and higher cylinder pressures. The higher top ring decreases crevice volume (space between the top ring, top of piston, and cylinder wall). Other changes in the combustion system (fuel injection pressure and fuel nozzle spray angles) along with this crevice volume reduction, have been used to reduce emissions and improve performance. These changes have allowed more partially burned fuel (soot) to be mixed with the oil on the liner. This soot laden oil is pulled into the sump by the higher ring position and thus the soot level in the oil is increased. Equally important, the higher ring position also creates a higher operating temperature for this ring.

Chart A

Oil History

Oil technology must keep up with changing engine technology! Engine oil technology of the past will not provide optimum life and performance for current and future engines. Engine oil has been forced to undergo changes to meet the increasing demands all engines are placing on it. This change is best tracked by the American Petroleum Institute (API) service category, which has been in existence for many years. The API CA category typifies the oils of the 1940's and 50's. The oils were upgraded for operation with poorer quality fuel in 1949 with the CB category. In 1951 API CC oil was released to handle moderate or severe duty engine applications which included turbocharged engines. All of these categories are now obsolete. The API CD category was introduced in 1955. It was adequate for most diesel engines and applications for many years. However, as engine technology changed, some diesel engines needed a better class of oil by the mid 1970's. This forced the development of another category of oil, titled API CE oil, in 1983. As engine performance continued to develop, improvements to engine oil continued, resulting in the newer API CF-4 category release in 1990. A new rating is in the development stages and will be the new oil standard in a few years (see Chart B).

Chart B

API CD And CE Verses CF-4 Oil

What is the difference?

1. The API "CD" category is a very broad classification. This means that there can be a wide variation in the performance level from one API CD or CE oil to another. The API CF-4 oil category requires more performance tests, to higher and stricter standards. This means API CF-4 oils have a narrower performance band within the API CF-4 range than API CD oils do. API CF-4 oils also have a higher average performance rating than API CD or CE oils.

2. The API CF-4 oil qualification test includes new tests, such as the Caterpillar 1K single cylinder engine oil performance test. This test defines a much higher oil performance level than the old API CD class (which was based on Caterpillar's 1G2 test developed in 1955). The API CF-4 oil qualification tests use the high top ring piston design that has reduced the top ring crevice volume.

3. API CF-4 oil also has a significantly higher piston deposit threshold temperature capability compared to API CD oil. This means that the API CF-4 oil can withstand higher temperatures before coking and becoming "cooked" into hard carbon on the piston crownland and in the ring grooves. API CF-4 oils, on average, have 60°C higher temperature capability than an average CD oil.

4. API CF-4 oil, by design and additive package formulation, has greater dispersing capabilities. This dispersancy additive package controls buildup of soot particle size in the oil by keeping soot particles dispersed more evenly. Poor soot dispersancy can lead to plugged oil filters, reduced oil change intervals, or an increase in ring and liner wear, resulting in reduced overhaul life.

5. Because of the oil consumption limit required to pass the API CF-4 qualifications most, if not all, API CF-4 oils are multi-viscosity oils. Engine oil qualification tests have proven that multi-viscosity oils have better oil control and minimize oil consumption.

In summary, API CF-4 oils have higher temperature capabilities, greater soot dispersancy capability, must pass additional tests at higher levels of performance, have a narrower performance band and are usually multi-viscosity. All of these factors result in a much better engine lubricant, leading to reduced oil related problems and/or longer engine life.

Caterpillar Recommendations

Since early 1992, API service category CF-4 oils have been and are the current recommendation for all 3500 diesel engines. This is the only way of assuring that the engine will provide optimum life to overhaul, as well as achieving the performance requirements. Providing one API recommendation also helps keep the recommendation as simple as possible.

However, if 3500 Phase 0 or Phase I engines are currently running on other than API CF-4 oil "successfully," these engines can, most probably, continue to use this oil. It should be recognized that "running successfully" on non - API CF-4 oil may mean that optimum engine overhaul life has not been achieved. Also, if the engine load factor or the oil formulation significantly changes, this may warrant having to change to API CF-4 oil.

If articulated (two piece) pistons are used in your engine, it is even more important to use API CF-4 oil. This piston uses a higher top ring due to higher performance ratings and emissions standards. Higher top ring grooves incur higher temperatures. Older oil technology (API CD & CE) may not be able to withstand the higher temperatures; and thus carbon may build up in the ring grooves. Carbon buildup in the ring grooves can result in poor oil control, piston ring scuffing the cylinder liner or piston seizures. Also, higher top ring pistons generally produce more soot, as previously explained. New oil technology (API CF-4) has better soot dispersancy; and thus can hold more soot in suspension without damaging the engine. It therefore becomes very important to use the proper oil in these engines. See Chart A for list of engines and serial number ranges that currently use two piece pistons.

All 3500 marine engines with an "E" rating are REQUIRED to use CF-4 rated oil.

Commonly Asked Questions

If an engine is operating on other than API CF-4 oil now, can it be switched to CF-4?

Yes - It is usually not detrimental to switch to a different performance oil in the 3500 engine. While this may not remove any of the "hard" carbon built up on the piston top crown and ring area, it should prevent more carbon from forming. However, changing to a different category oil can "clean up" the inside of the engine crankcase, which can result in a temporary increase in oil consumption. This cleaning action in the crankcase may also cause a temporary reduction in oil filter life, and filter change interval should be reduced with the filters cut open and inspected until the amount of carbon "sludge" in the filter is considered normal.

What if API CF-4 oil is not available in my area?

The first step is to ask for it at your local oil supplier. Oil suppliers and refinery's operate largely on a customer driven basis. Your need for oil meeting the API CF-4 category should be communicated directly to your local oil supplier. The additive technology is available worldwide for blending API CF-4 oils. You can also talk to your Caterpillar Dealer to see if Caterpillar Diesel Engine Oil (DEO) CF-4 is available. Help may also be available at your Caterpillar subsidiary offices.

Is API CF-4 oil more important in some applications than others?

The importance of API CF-4 oil is related to both the two piece pistons and/or to the load factors on the engine. A higher load will elevate the temperature of the top ring, which in turn will accelerate the formation of carbon if the incorrect oil is used. The rating and load factor both influence how quickly carbon can build up. Even engines running at lower ratings may experience oil related problems from a poor performing oil.

Can "warranty" be affected if the wrong oil is used?

Caterpillar warranty covers material and workmanship for which Caterpillar is responsible and always applies. Caterpillar also provides recommendations for their product, one of which is the quality and performance level of lubricant. Caterpillar would not expect to contribute towards the repair of a failure that was attributable to not following published recommendations.

What can using the wrong oil cause?

Using API CD & CE oil can cause carbon packing around the upper piston ring and crownland. This in turn can cause several levels of failure, including reduced engine life, increased oil consumption, and possible catastrophic failure of the engine such as piston scuffing and seizure. These oils may not have high enough soot dispersancy capability to keep soot suspended, which can also cause engine damage. Unwanted deposits can also form on the valves, leading to valve failures or excessively worn valve guides.

Why should I use this oil, even though it may cost more?

API CF-4 oil provides the optimum maintenance intervals and maximum overhaul life, while older oils may shorten them. Besides maintenance and overhaul life, engine performance (emissions, smoke, fuel consumption, etc.) may be adversely affected over time by using the incorrect oil. Also, unscheduled failures as a result of oil can lead to extensive repairs and excessive downtime. In every "before" and "after" comparison, engines run with CF-4 oil have been noticeably cleaner inside than engines run with CD oil.

What does "running successfully" on API CD oil really mean?

If current 3500 Phase 0 or I engines are running with satisfactory maintenance intervals and overhaul life, API CD or CE oil can continue to be used. However, if new 3500 Phase II engines are installed, CF-4 should be used, and if the load factor on existing engines is increased, the need for API CF-4 oil may increase. Even though API CD or CE oil may provide perceived "satisfactory" performance, API CF-4 oil should provide noticeable improvements inside the engine.

What is Caterpillar currently doing to help?

The Caterpillar Fluids program was developed to help address these needs. They are continually working to provide a consistent source for improved performance lubes.

What is the Caterpillar Fluids Program?

The Caterpillar Fluids program was initiated in 1986 to influence, develop and distribute future lubricants, providing the optimum life for Caterpillar products worldwide. This program led to the development of the Caterpillar branded line of engine oil, as well as the API CF-4 service category.

What type of oil related problems have been seen on 3500 Phase 0 or Phase I engines?

Types of reported problems related to incorrect oil have included:

* liner bore polishing

* excessive carbon buildup on valves

* excessive blow-by

* turbocharger failures

* excessive oil consumption

* premature overhauls

* premature valve failures.

Will a shortened oil change interval with API CD or CE oils provide similar engine operation to a normal oil change interval with a API CF-4 oil?

NO - It is not degradation of the API CD or CE oils which cause deposits at the higher temperature, but a difference in the oil additives. The older oil formulations do not function properly at the higher piston temperatures of the newer engine designs. This allows the carbon to start forming almost immediately, which means a reduced change interval will not prevent damage to the engine.

Will the new "low sulfur (0.05%)" fuel allow me to use API CD or CE category oil?

NO - Any older Caterpillar direct injection engines that have been using API CD or CE oils should upgrade to API CF-4 oil when switching to low sulfur fuel. Limited engine test data indicates API CD and CE oil formulations may produce more top ring groove and piston top land deposits than the API CF-4 oil with low sulfur fuel.