Though data logging is verboten...
Though data logging is verboten during the money runs of the AMSOIL Engine Masters Challenge, the team was able to make sure the engine didn't lean out unexpectedly by installing a simple Auto Meter mechanical fuel pressure gauge.
Chrysler engineers spent enough time designing the oiling system for the Gen III that Bischoff felt the OEM oil pump was more than adequate for the combination. Aside from detailing the oil passages and lowering the pressure in the pump, it was basically stock. With low-tension rings and a hydraulic roller cam, the short-block is certainly ahead of its low-brow flat-tappet predecessors, but where the engine really starts to make power is on the north side of the deck.
BES is definitely a player when it comes to CNC-ported Hemi heads, and they've spent a good deal of time figuring out how to get the most out of the stock castings. "We used some late-model 5.7 heads on it and we tried some, for lack of a better term, tricks. We didn't pay so much attention to the flow bench. We kind of went more for cross-sectional area. They didn't flow very well. As a matter of fact, our 6.1 heads that we do every day for HHP with the stock size valve actually out-flow them. But obviously these performed pretty well." New intake seats were installed to handle the massive new intake valves, and the bowls were worked to match the combo. Even downplaying the flow numbers, Bischoff alluded to the power potential for the heads by letting slip that they flow right about 360 cfm. "With a mild port job on the 6.1 heads and a 2.08 valve, they'll do that, so that's what really makes the Hemi work really well without opening the valve a mile."
Simple math determined the...
Simple math determined the injector size. Desired HP × Brake Specific Fuel Consumption (typically .500 to .550 for pump gas) / number of cylinders = pounds of fuel used per hour. This is then usually divided by a normally recommended maximum duty cycle of 80 percent, or 0.8 to get the injector you need. In Bischoff's case it, was 700 × .45 (very efficient) / 8 = 39 lb/hr, and we see that at that rate he was at 86 percent duty cycle.
Another key factor in choosing the engine was the availability of the skyscraper Drag Pak single-plane intake manifold from Mopar Performance. Dale Aldo of Mopar Performance says they are completely committed to the Gen III engines and have been stepping up with a slew of parts for them including that tall single-plane, two shorter single-plane intakes (carb and EFI), and even a trick dual-quad intake. Aldo also mentioned that they have just received their first batch of aluminum 6.1 blocks, so keep an eye open for those to be available soon.
One of the neato factors with Hemis has always been the rocker arm setup, and the Gen III is no different there. With a net-form casting, the rockers waste no material and their only downside is a lack of adjustability. Regarding stock Hemi rockers, Bischoff says: "They're kind of light, but they work very well. We've never seen a failure out of them with the street car stuff that we've done. For this application, we wanted to do well in the contest and we thought for sure we needed the adjustability of the Jesel valvetrain. We weren't going to do the Chrysler engine until they opened the rule up where we were allowed to have a modified lifter. Because the Chrysler Hemi's oil backward-they oil from the rocker down to the lifter-you can't put a Jesel rocker on unless you oil from the lifter up to the rocker arm." Apparently, this was done as part of the Multi Displacement System feature that shuts off certain cylinders when under low load to save fuel. Bischoff modified the stock lifters by drilling a small hole in the side, allowing oil to travel up the hollow Manley pushrods to the rockers.
A fairly simple set of Schoenfield...
A fairly simple set of Schoenfield headers was able to make great torque, thanks to their long primary tubes and the small initial step to keep velocity high through the exhaust.
BES opted for a 2.25-inch...
BES opted for a 2.25-inch bladed ACCEL throttle body with a tall inlet hat attached to align the airflow as it rammed into the engine.
The rest of the competitors...
The rest of the competitors turned green when the Hemi showed up with this new "skyscraper" intake manifold. A super tall plenum and straight-shot runners make this an engine builder's dream.
Beneath the valve covers,...
Beneath the valve covers, a set of Jesel adjustable rocker arms is mounted in alignment with the valves instead of on a common inline shaft as in the stock setup.
Single-groove valve locks...
Single-groove valve locks replace the factory triple grooves for better reliability in the high-performance application. Also, stress relieved and polished springs with titanium retainers are a must for late-model Hemis looking for longevity with an aftermarket cam swap.
One of the main benefits that...
One of the main benefits that Bischoff claims the Hemi possesses is that the valves open away from the cylinder walls, allowing for a large-diameter valve without being shrouded as it would with a Wedge head.