Expert Report
Below are excerpts from an expert report used to obtain compensation for Land Rover defects.
In researching the head gasket failure and catastrophic engine failure concerns of the 2002 and 2003 model years of the Land Rover Freelander manufactured with the KV6 2.5 liter aluminum V6 engine. I have found information, in my professional opinion, that would indicate a design defect with this engine that is the cause of these concerns.
First, I would like to provide a brief description of this engine. This engine is referred to as an aluminum V6 engine because it is manufactured using an aluminum cylinder block along with aluminum cylinder heads. Many internal components are however made of steel and iron. Most automotive manufacturers today offer aluminum V6 engines that would fall under this description. The KV6 engine shares several technical features with other manufacturer’s aluminum V6 engines of the 2002-2003 period such as double overhead camshafts, four valves per cylinder design cylinder heads, and variable intake manifold tuning.
One distinct design feature of the KV6 engine that makes it different from common aluminum V6 engines is the use of slip fit steel cylinder sleeves (or liners) in it's construction. All of the aluminum V6 engines that I have been exposed to (from Chrysler, Ford, GM, Honda, and others) use a press fit cast iron cylinder sleeve. Typically, engines using the cast iron cylinder sleeve design have demonstrated virtually no issues related to the sleeves or their integrity as assembled in the aluminum cylinder block. This is not the case with the KV6 engine design. I discovered an alarming number of reports describing failures (head gaskets and engine seizures) related to the sleeves of the KV6 engine.
Typically when aluminum cylinder block-iron sleeve engines are manufactured, the cylinder bores of the aluminum block are slightly smaller than the outside diameter of the cast iron sleeves before assembly at room temperature. This difference in sizes is referred to as interference and won’t allow assembly while the block and sleeves are both at room temperature. The block is heated to over 600 degrees F to allow it to fully expand before the cool or room temperature sleeves are pressed (forced) into place within the block and then allowed to cool at a controlled rate as an assembly. The amount of force used to press the sleeves into the block varies with designs and can be from a few hundred pounds to a few thousand pounds. This process assures a permanent, unchanging fitment of the sleeves to the cylinder block.
With the Freelander engine the sleeves are simply slipped into place as the engine is assembled. The sleeves of the Freelander engine have a shoulder machined into them about midway down the outside of the sleeves which rests on a machined land within the cylinder bores of the engine block as the engine is assembled. The sleeves essentially have two outside diameters with the lower end being smaller than the upper. It would be critical that these machined surfaces be of high quality and precision as once assembled, the contact area of the two surfaces would have to provide a seal between the coolant jacket of the cylinder block and the engine crankcase where the engine oil is collected and stored in the engine oil pan. The Freelander engine design relies on the clamping force of the cylinder head and gasket of the assembled engine to maintain a tension against the sleeves from the top to ensure a seal at the two machined surfaces described. The cylinder head gaskets are manufactured with a metal compression seal ring that is mated to the tops of the sleeves and these compression seal rings have a designed, calculated "crush" that upon assembly, ensure a permanent seal between the high temperature and pressure combustion gases, and the separate coolant and oil circulation passages of the assembled cylinder block and heads. It is important to note that the tops of the sleeves of the Freelander engine are designed to be flush with the head gasket surface of the cylinder block when assembled so that the head gasket will perform it's purpose of sealing effectively.
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