1993 Cadillac Eldorado Owner's Manual - Page 351

The Northstar engineis designed to require less maintenance than many other DOHC V-8 engines. Engine systems are designed to remind the driver when service is required. Anoil life index indicator monitors ongoing operating conditions and reminds the driver an oil change when is needed. A low coolant warning message keeps track of the level of this vital fluid. Direct actinghydraulic tappets provide maintenance free zero lash operation of the 32 valves from idle to the 6500 rpm redline. The camshafts are driven by a two stage roller chainassembly which is designed to provide quiet maintenance free operation. Platinum tipped spark plugs increase the replacement interval to 100,000 miles. The fourvalve per cylinder design provides more efficient engine breathing which results in higher power than comparable two valve engines. The centrallocation of each sparkplug ensures a fast and complete burningof the fuel/air mixture.The induction system uses smooth thermoplastic tubes to channel air into the cylinders. The smoothness of the tubes is equivalent to the elaborate port polishing methods used for race car engines. Careful design using the shape and length of the tubesboosts horsepower by using sonic pressurewaves created by the motionof the inlet valves to increase the amountof air entering eachcylinder. The Northstar engine also designed to be very durable. Thealuminum is block has cast-in-place iron cylinder liners forgreater wearresistance. High strength forged steel connecting rods support the free floating piston pins in bronze bushings for superiorhigh speed performance. The a fillits of the nodulariron crankshaft undergo high pressure compression rolling operation toimprove their resistanceto fatigue. Quiet operation is enhanced by the use of special materials anddesigns. The front cover of the engineis stamped from laminated steel which damps out noise. Special cam cover gasket seals isolatevalve train operation. The fuel injectors are placed inside the induction system housing to eliminate theclicking noise which is common to other fuel injected engines. The Northstar engine designed to provide years of efficient, reliable, is satisfying operation. We think it is also justplain fun to drive. 337