When it's all said and done, it's about the power. Almost 12 years ago, Lingenfelter Performance Engineering (LPE) built us a 420ci small-block track-day warrior. This is an interesting 4.155-inch bore and 3.875-inch stroke combination that was intended to maximize torque and horsepower between 3,000 and 6,000 rpm with an emphasis on torque. To this end, it made 525 hp and 540 lb-ft of torque all below 6,000 rpm. It worked so well, we've taken to calling this engine Brutus. It went into our much-abused '65 Chevelle, and we planned to run it hard, so it had to be durable. Toward this end, Lingenfelter spec'd some great parts including a Bow Tie iron block containing a 4340 forged steel Crower crank and rod rotating package, Air Flow Research 195cc heads, and an ACCEL/DFI electronic fuel injection system using the ACCEL/DFI SuperRam intake.
Lube It Or Lose ItDespite Brutus' size, we initially chose to run a stock-type oil pan with a mundane '69 Z28-style windage tray. This worked fine at first, but chassis mods and gumball tires have created sufficiently high lateral g's to push the oil right out of the sump, causing oil cavitation problems. After a tour through the Moroso catalog, we decided on a kick-out, road-race style pan that would give us some much-needed oil control and still clear the Chevelle's steering linkage. In the January issue, we backyard-tested this oil pan ("Slip-Slidin' Away," Jan. '04, pg. 38). While the testing was backyard crude, it did reveal that the Moroso pan was capable of oil control far superior to the stock pan and windage tray.
In the car, the engine is also equipped with an external filter and an Earl's water-to-oil cooler, but even with these additional components, we decided to stick with a standard volume, standard-pressure Moroso performance oil pump. The reason for this is to minimize the parasitic losses through the path the oil has to travel. The oil cooler is an essential part of this combination since even just three or four full-tilt blasts around a road course can send engine oil temperature soaring close to 275 degrees or higher if not controlled with a cooler. In fact, the conservative Earl's cooler we're using is actually a bit too small for even this 500hp small-block.
Finally, we fully intend to run pure synthetic oil in the 420, and we may test a couple of different oils in the near future. Castrol, Lucas, Mobil 1, and many other companies offer pure synthetics that have the temperature stability to handle 275-to-300-degree oil temperatures that are almost commonplace for track-day excursions. Synthetic engine oil is an absolute requirement for track days if you're not running an oil cooler.
Induction NoticeFor the other half of our effort, we decided it was time to retire the original Gen VI ACCEL/DFI injection package that had powered our small-block for so many years. The system worked great, but DFI engineer Joe Allamandine promised us a much better resolution with the new Gen VII system. While intended to run as a sequential fuel injection system, we decided to do our comparison testing in batch fire to reduce the initial variables and to quickly get acquainted with the new system. Later, we can look at the advantages of converting to sequential. Just converting to the Gen VII system promised more finite control over the fuel and spark and the potential for wide-open throttle feedback control using a wide-band oxygen sensor.