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 on a valve and guide caution for 11.0L M11, IAM and QSM Cummins diesel engines. As a product improvement, Cummins implemented chrome intake valve stems and a reverse scroll valve guide for all locations beginning with engine serial number 35135680 built in July 2005.

These reverse scroll guides were implemented to prevent excess exhaust valve guide wear in the lower portion of the valve guide inside diameter. The reverse scroll guide has 50 percent more surface area in the lower portion of the valve guide inside diameter.

The valve guides are the same for the intake and exhaust valves. Engines prior to ESN 35135680 were built with chrome plated exhaust valve stems and non-reversed scroll valve guides. To accommodate the change in the valve guides, it was required that the intake valve stems also be chrome plated to prevent excess wear on the intake valve stem. The chrome plated intake valve stems were released a month before the release of the reverse scroll valve guides in order to prevent usage of non-chrome plated valve stems with the reverse scroll guides. Do not use intake valves from prior serial number engines in cylinder heads with reverse scroll valve guides.

Intake valves with chrome plated valve stems (p/n 4926069 or 4955239) must be used on cylinder heads that have the reverse scrolled valve guides (p/n 4923471) or reverse scrolled oversized valve guides (p/n 4923473).

Either chrome plated intake valve (p/n 4926069, or non-chrome plated intake valve (p/n 3417778) can be used on cylinder heads that have non-reverse scrolled valve guides (p/n 3328786).

Reverse scroll valve guides can be identified by the inner threading (spiral) of the guide at the top end, as opposed to no threads (spiral) on the non-reverse scroll guides.

Engine Builders: The AERA Technical Committee offers the following information on a cylinder head gasket caution on 2003-2006 Ford 6.0L VIN P diesel engines. This caution should be referenced any time head gaskets or cylinder heads are being replaced.

The manufacturer of this engine uses two separate facilities, one in Indianapolis, IN and the other in Huntsville, AL. While both locations build engines with the same critical data, three cylinder head variations have been used. The chart Vehicle Application and Part Number Detail – Kit, Cylinder Head provides engine serial number information to help in determining which cylinder heads were used.

The cylinder head gasket and locating dowels also changed in the 2006 model year to accommodate an increase in the dowel size from 18 mm to 20 mm. Assembling the engine with the wrong head gasket for the application will lead to engine damage. The revised dowel hole was made to accommodate the larger head bolts to be used in the new 6.4L diesel engine and communization for manufacturing purposes. The injector clamp design and associated cylinder head casting support area were also modified on the changeover date in early 2006.

If the dowel holes between the head and block are different sizes, a special “stepped dowel” (p/n 6C3Z-6B041-B) is available to accommodate proper assembly. The cylinder head gasket and injector clamp versions are not interchangeable; they must be used with the corresponding cylinder head versions. Refer to Chart 2 to determine application and correct part number use.

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