Words Richard Holdener
Well folks, it looks like the gang over at Blueprint Engines (BPE) has done it again. While you might think their customers would be plenty satisfied with the many performance offerings for Ford, Chevy, and Dodge, you’d be wrong. Apparently, BPE recognized that big-block Chevy owners were not quite as well represented as other engine families, and they took it upon themselves to rectify the situation. In addition to the many crate motors, ProSeries combos, and even short blocks they offered, BPE decided to add something for fans of power adders. After all, what goes better with big displacement than boost or nitrous, right?
They might well be on to something, as what truck, boat, or street/strip muscle car guy wouldn’t love to combine a big-inch stroker with boost from a big roots or centrifugal supercharger? Naturally, the big Power Adder motor from BPE will accept a turbo (or turbos) and even a healthy shot of nitrous, but for this test, we decided to combine the 540-inch big block (the Print) with boost (Press) from a Vortech YSi centrifugal supercharger.
Before we get to the test, here is a rundown on what the Power Adder motor from Blueprint Engines had to offer, even before adding boost. Like all of the (complete crate) offerings from BPE, the 540-inch big block was ready to rock right out of the shipping crate. Our confidence in the stroker combination was high, as the BPE motor had previously been run on the dyno and even included a dyno printout to verify its rated power output. Despite knowing the difficult environment the Power Adder combo might be subjected to, BPE was confident enough to offer one of the best warranties in the industry — 30 months/50,000 miles.
To ensure the required intestinal fortitude, the BPE Power Adder big block featured a number of important upgrades. The BPE HD, four-bolt block was treated to a 4340, forged steel crank, forged H-beam rods, and matching (4032) forged aluminum pistons. The result was not only sufficient internal strength, but a boost-friendly static compression ratio of 8.5:1 (when combined with their 118cc combustion chamber, rec-port aluminum heads). Knowing a big-inch motor required a healthy cam profile, the 540 Power Adder received a solid-roller cam with .652 lift, a 255/262-degree duration split. and 114-degree lsa.
Because the Power Adder was destined for pressure, the boys at BluePrint decided to supply their 540 sans intake, carb, and distributor. Before we could run boost on the 540, we needed to complete the long block. To the BPE 540, we added a single-plane Weiand Team G intake, a Holley 950 XP carb, and MSD billet distributor. The single-plane design of the Team G provided the big block with plenty of airflow, while allowing the motor to produce peak power higher in the rev range than a typical dual-plane design. Since we planned on adding boost, the extra spark energy supplied by the billet distributor and MSD 6AL ignition amplifier was a critical element in the success of the boost big block.
As indicated, the BPE 540 had previously been run on the engine dyno, but just to be sure, we ran it through a series of break-in cycles before establishing our own baseline. After one jet change and setting the total timing at 37 degrees, the Power Adder 540 responded with 649 hp at 6,100 rpm and 629 lb-ft of torque at 4,500 rpm. Satisfied with our baseline, now it was time for some boost!
To prep for pressure, off came the Holley 950 XP carburetor, replaced by a dedicated blow-through Holley from Carb Solutions Unlimited (CSU). The CSU carb featured all the tricks for use on a blow-through application, including boost-referenced power valves. The carb was combined with a blow-through carb bonnet and custom discharge tube we whipped up from aluminum tubing and a few silicone couplers.
Boost was supplied by a Vortech YSi supercharger. Looking at the specs, we see that the YSi was a perfect match for the BPE 540. According to Vortech, the YSi was capable of pumping out as much as 30 psi, supporting more than 1,200 hp, and even featured a peak efficiency rating of 78 percent (translation-low charge temperature). In addition to the YSi, Vortech also supplied the necessary mounting brackets, cog drive pulleys (blower and crank), and idler/tensioner assembly. The 80-tooth crank pulley combined with the 32-tooth blower pulley to produce a drive ratio of 2.5:1. This combined with the internal step ratio of the blower and maximum engine speed of 6,000 rpm to produce an impeller speed of 51,700 rpm, well below the 65,000 rpm maximum listed by Vortech. On our BPE 540, this produced a maximum boost pressure of 13.5 psi.
Before running the supercharged 540, it was necessary to punch a hole in the oil pan to serve as an oil drain for the blower. We ran a dedicated oil line to the blower, then routed a section of tubing to the fitting tapped into the oil pan. Once everything was in place, we began tuning the CSU carburetor, but it took very little tuning before the power numbers started to climb rapidly. Naturally, we also filled the tank with race fuel and dialed back the total ignition timing to less than 30 degrees.
With everything dialed in, we were eventually rewarded with peak numbers of 1,060 hp and 958 lb-ft of torque. The boost curve started at 5.7 psi at 3,700 rpm and rose to 13.5 psi at 6,000 rpm. A fuel supply issue with the dyno limited us to 6,000 rpm, but there was plenty more left in the combination with additional engine and/or blower speed. Despite the limitations, PRESSure from the Vortech improved the power output of BluePRINT 540 by more than 410 hp — Printing Press indeed!
Sources: ARP, arp-bolts.com; BluePrint Engines, blueprintengines.com; COMP Cams, compcams.com; CSU, cucarbs.com; Holley/Hooker/NOS, holley.com; MSD, msdignition.com; Vortech Superchargers, vortechsuperchargers.com