The most dramatic personality change for Brutus was the switch to ACCEL/DFI's impressive Lingenfelter-designed single-plane multipoint EFI manifold. In a quickie test several months ago, we learned just how strong this manifold is. Since the original SuperRam-equipped Brutus made more torque than we could use on the road course, we decided to trade a little torque off the bottom for more horsepower by using the new single-plane intake. We were hoping for an increase of 15 to perhaps 20 more hp from these new parts, but we got much more.
Dyno Test DayOnce our dyno guy Ed Taylor had the 420 up on the dyno, it only took a few minutes to create a basic fuel curve using the ACCEL Gen VII's configuration software after inputing the engine's size and camshaft information. The engine instantly fired up and idled, and it wasn't long before we were making power. This engine does sport 11:1 compression, but even with aluminum heads and this healthy Comp cam, we had to mix 50 percent 100-octane unleaded with our 91-octane premium pump gas to allow the engine to run at its maximum ignition timing.
Taylor initially configured the 420 with the ACCEL four-barrel style throttle-body that actually cranked out a respectable 537 hp and 528 lb-ft of torque. Then we tried the larger three-barrel throttle-body and picked up a little power-up to 546 hp and 532 lb-ft. Then we tried the largest rated throttle-body, and the power jumped yet again, this time to an astounding 560 hp at 6,200 and 547 lb-ft at 4,600 rpm. We were hoping to pump the power up by 15 or perhaps 20 hp, but this killer ACCEL intake ramped up our horsepower increase a total of 35 hp while the torque peak moved around some, but actually increased slightly!
ConclusionOverall, we were thrilled with our competition-proven Brutus 420ci small-block. Considering what this engine has been through, to make 560 hp with this kind of durability is outstanding. Granted, this is hardly a budget exercise. But it also proves that purchasing quality parts and assembling the engine properly always proves to be worth the money invested. Just for fun, we plugged the 560hp power curve into the Quarter Pro dragstrip simulation program using a 3,600-pound Chevelle with a TH-400 trans, medium sticky 26-inch-tall tire, 3.55:1 gear, 3,000-rpm stall converter and were surprised at the 11-teen e.t. and the 120-mph-plus trap speed. That's what displacement and a solid torque curve will give you. Oh, and the horsepower helps too
Cam SpecsWhen this engine was originally built, Lingenfelter chose the original specs list in the first cam. The latest version of this cam is the XR 286. We decided not to change cams, but note that for the same advertised duration, the Xtreme cam offers more duration at 0.050 and greater lift on both the intake and exhaust sides. This would probably mean a little more horsepower without sacrificing torque. We are also using 1.6 rockers, which bumps the lift another 0.035 inch.
| Camshaft | Duration | Duration | Lift | Lobe |
| (Advertised) | @ 0.050 | (inches) | Separation |
| SR288 |
| Int. | 280 | 236 | 0.550 | 110 |
| Exh. | 288 | 244 | 0.550 | |
| XR286 |
| Int. | 280 | 242 | 0.570 | 110 |
| Exh. | 286 | 248 | 0.576 | |