Edelbrock Performer RPM Package - Small Displacement Big Punch

404 hp on the Motor & 513 hp on the Sauce out of a 327ci Small-Block

Bob Mehlhoff Dec 13, 2006 0 Comment(s)

The folks at Edelbrock have been busy refining their Total Power Package systems, making them hassle-free for anyone who wants a tested and proven engine combination. Edelbrock has taken all of the guesswork out of choosing the right parts by including all of the top-end pieces for your application and dyno-testing to ensure excellent power while retaining lots of drivability. This system offers two choices depending on engine operating rpm. There is the Performer Package (1,000-5,500 rpm) and the Performer RPM Package (1,500-6,500 rpm). For even more extended power at high engine speeds, the Performer RPM Package now offers a hydraulic-roller camshaft.

We wanted to see how much power could be had with one these systems, especially since we were planning to use a shorter-stroke 327 engine, to reduce the parasitic loss of a larger 350 or 383, for our test. Given that we have plans to install the engine in a manual-transmission car with performance gears, we chose the Performer RPM Package and the Performer RPM hydraulic-roller camshaft. Of course we couldn't leave well enough alone and opted to spray a small 100hp nitrous shot from the Edelbrock Performer RPM nitrous line.

But before we could bolt any of these parts to our 327, it was in dire need of a rebuild. This particular 327 was pulled out of a Chevy pickup several years ago, only to be stored indoors. To say it was greasy is a total understatement, so we began our quest at Larry's Performance in Montebello, California, where we stripped the block down, hot-tanked it clean, and checked it for cracks and any needed machining. The cleaning and inspection process showed the block was in good condition with no cracks and only needed boring (0.030 inch over) and resurfacing of the deck. The new bore size increased the engine's displacement to 332 ci. The crankshaft passed inspection and only needed 0.010 inch ground from the main and rod journals. After a day of machining at Larry's Performance, the crew assembled the engine with new Speed-Pro forged pistons, Scat connecting rods, and Clevite bearings, and installed the Edelbrock hydraulic-roller cam. We then installed a new Milodon pan and timing cover and attached the Edelbrock heads with a set of Milodon head bolts. Up top we added a set of Comp Pro magnum 1.52:1 roller rockers and a Performer RPM Air Gap intake and Edelbrock Performer 800-cfm carburetor. With the engine assembled with new parts, we headed across town to the Edelbrock dyno to measure the results.

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We started with a 327 that had been sitting in a neighbor's basement for 15 years. The cost of the engine was "Just come and get it out of here." It turned out to be a great core with a standard bore.

Larry's Performance cleaned and checked the engine before boring the block 0.030 inch over. The larger bore size (4.030 inches) increased the displacement to 332 ci. The stock crankshaft was cleaned and turned just 0.010 inch under on both the mains and the rods. While we assembled the engine, we slipped the new Edelbrock Performer RPM hydraulic-roller camshaft in.

Larry Performance installed eight forged Speed-Pro pistons with Sealed Power rings and Scat connecting rods with ARP rod bolts. All of the moving parts were balanced before assembly.

We added an Edelbrock Cloyes True-Roller timing chain for accurate movement of the camshaft. The pistons we used have four valve reliefs. The new deck surface measured 0.023 positive (above the piston).

After assembling the long-block, we were ready to head over to Edelbrock's dyno facility. The roller lifters for this project were there waiting for us, so we postponed installing the intake and Comp Pro Magnum roller rockers until then.

The Edelbrock RPM Performer cylinder heads feature 2.02/1.60-inch valves with 64cc combustion chambers and angled plugs. The spark plugs are angled at the center of the cylinder in order to improve combustion efficiency. The production 170cc intake port on this cylinder head worked well with our 332.

Curt Hooker and Robert Jung installed the roller lifters and pushrods, and adjusted the guide plates before installing the Comp Cams roller rockers.

The Performer RPM Nitrous kit basically uses a plate and two solenoids (nitrous and fuel). The kit comes also with an assortment of jets to change the power output from 100 all the way up to a 250 shot.

For best performance it's important to keep your nitrous bottle more than 50-percent full and the bottle pressure at 900-950 psi. To raise the pressure we used a bottle heater to raise the core temperature to 87 degrees F.

On our initial dyno test with the nitrous we almost made 500 horses. Not enough-we had to hit the 500 mark or better so we made a minor jet adjustment. This meant from the standard 100-horse 55 nitrous/61 fuel jetting we slightly increased only the nitrous side up to a 56 jet.

The small jet increase worked well and we hit 513 horses and 539 lb-ft of torque. Tuning is relatively easy with nitrous. The entire Edelbrock Power Package worked flawlessly, so we pulled the motor off the dyno cell and called it a day.

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