Tech Notes - Engine Builder Magazine

Tech Notes

Engine Builders: After 75,000 miles, your customers’ engines can begin to show their age. They may consume a bit more oil or oil could leak past intake valve stem seals. Higher Mileage specialty motor oils typically contain additives that condition the rubber seals to help reduce oil consumption. They can also have high quality base oils that are less likely to evaporate when near the combustion chamber. An example of this type of specialty oil is Quaker State® Higher Mileage Engine™ with Slick 50®, which is specifically engineered to help reduce oil consumption.

Another way these specialty oils help provide performance is by helping provide a better seal around the aging piston rings by incorporating thicker oil viscosity.

After modifying an engine to boost horsepower, some engine builders and automotive enthusiasts look for a motor oil that provides the right balance among oil viscosity, oil flow and oil pressure to help free up as much horsepower as possible without sacrificing bearing life. Today’s racing specialty oils such as Q Racing™ come in a variety of viscosity grades and also contain select friction modifiers that make the racing oil slippery to help free up more horsepower.

Racing oils may also address the wear sometimes associated with stiffer valve springs added to help keep the valves from “floating” at higher rpms. These oils include additional antiwear additives to compensate for the increased loads the stiffer springs place on the camshaft.

As you can see, an oil company does have the ability to develop different engine oils to not only meet the specifications listed in a car’s owner’s manual, but also to modify engine oils to meet your customer’s particular driving demands on the road or on the race track.

The preceding information on specialty engine oils has been provided by Quaker State.

Engine Builders: The AERA Technical Committee offers the following information regarding a revised lower thrust bearing for 2000-2003 Ford/Navistar 7.3L diesel engines. It has been reported that service technicians have been confused while re-assembling the crankshaft into engine blocks for the above engine. The confusion exists while installing the lower thrust bearing shell as it has no locating lug.

This unwarranted confusion is the result of a revised bearing that was introduced with the model year 2000 engines. The new lower thrust main bearing (#5 position only) was released for production and service for ease of installation. The bearing was modified by removing the locking tab.

The new production and service bearing now affords service technicians the opportunity to install and orient the lower thrust bearing in either direction. Additionally, the elimination of the locking tab for the #5 main bearing lower thrust position prevents assembly interference issues with the lower thrust bearing locking tab and the #5 main bearing cap. The functionality of the new bearing is not impeded because it is secured by the upper bearing with a locking tab. Service bearings are available in standard and three common undersizes (see Figure 1).

Main Set P/N Description
1812325C92 Standard Crankshaft Bearing Package
1812326C92 .010″ (.25 mm) Crankshaft Bearing Package
1812327C92 .020″ (.50 mm) Crankshaft Bearing Package
1812328C92 .030″ (.75 mm) Crankshaft Bearing Package

Figure 1: Main bearing sets for 2000-2003 Ford/Navistar 7.3L diesel engines.

Note: Service bearing for lower main bearings 1-4 and crankcase (upper 1-5) continue to require the locking tab feature.

Engine Builders: The AERA Technical Committee offers the following information regarding the lower intake manifold installation for 1993-’96 Ford 4.6L VIN V engines. This engine is the DOHC design used in Lincoln vehicles.

This engine uses a combination of twenty long and short studs and nuts as well as four mounting bolts to secure the lower intake manifold to the cylinder heads. The correct installation procedures must be used to obtain an effective long lasting gasket seal.

Review the steps and procedures listed below before attempting installation.

  1. Clean and verify cylinder head and intake manifold surfaces are true and flat within .002″ (.051 mm).

  2. Install new intake manifold gaskets.

  3. Following the sequence shown in Figure 2, tighten fasteners numbered 5, 7, 9, and 11 to 9-11 ft.lbs.

    Figures 1 & 2

  4. In sequence, tighten the remaining numbered fasteners to 13-16 ft.lbs.

  5. In sequence, rotate all twenty fasteners an additional 85-95° as shown in Figure 2.

  6. Tighten the 4 (A, B, C, D) intake manifold runner control (IMRC) bolts to 71-89 in.lbs. in sequence (A, B, C, D) as shown in Figure 3.

  7. In sequence, tighten them an additional 85-95°.

For information on receiving all of AERA’s regular monthly technical bulletins and other association services and benefits, call toll free 888-326-2372 or send an e-mail to [email protected]

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