We're famous for our low-buck engine builds. Longtime readers have been treated to high-winding small-blocks with stock rod bolts and sketchy, solid-cammed, big-bore stump pullers that we're not afraid to rev way past the recommended redline. Our secrets are to scrounge a short-block from a wrecking yard, fix only what is necessary, assemble the engine ourselves, and wear the proper protective head and eye gear when standing near the running engine. This engine is different. Demon Engines in Sante Fe Springs, California, sells low-buck 454s as service replacements, advertising an honest 400 hp and more than 500 lb-ft for just $2,650 outright. What intrigued us about the Demon engine was that it came nearly complete, from intake to oil pan, minus only the carburetor. It features a four-bolt block and is available in either Mark IV or Gen V guise with no changes in power output. Obviously, for less than three large, we didn't expect to find many racing components. What we did find was a motor perfectly suited to the combination of power level and engine speed. The four-bolt block was precision-machined then fitted with new rings and bearings along with a factory cast-steel crank, reconditioned factory rods (including a rod bolt upgrade), and 9.4:1 forged pistons from Probe Racing. According to Demon Engines, the short-block can stomach power levels above 700 hp and 7,000 rpm and heavy doses of nitrous. We may well take up Demon on its offer to abuse this engine in the future, but for now, we were interested in seeing what this baby had to offer in as-delivered trim. All the Demon 454 combinations start out as BBC core motors. To ensure quality, Demon handpicks cores for its low-buck applications. The 454s are available in Mark IV and Gen V configurations with no difference in power production. All the Demon 454 combinations start out as BBC core motors. To ensure quality, Demon hand Producing 400 hp is not terribly difficult in a motor displacing 454 ci. Truth be told, the motor actually displaces 461 ci thanks to a 0.030 overbore, but even 400 hp requires something more than a stock cam profile. Keeping costs down meant skipping the more expensive roller cam and sticking with a hydraulic, flat-tappet version. The mandatory loss of zinc content in current motor oils had many enthusiasts abandoning flat-tappet cams, but according to Demon Engines, there is no need for concern with proper preparation. In fact, Demon was quick to point out that it has never lost a flat-tappet cam or lifter on any of its engines. The company's procedure for a long life includes moly-based assembly lube on the cam and lifters prior to installation, prelubing the motor prior to start-up, and use of a high-quality Lucas oil and high-zinc break-in lubricant. Perhaps a touch of overkill, the procedure has proven successful, so we followed it to the letter prior to starting our 454. The cam supplied in our 400hp combination was a mild Comp Xtreme Energy XE268H that offered a 0.515/0.520-lift split, a 224/230 duration at 0.050, and a 110-degree lobe-separation angle. Small by big-block standards, the grind offered an impressive combination of idle quality and torque production. Each Demon 454 features a four-bolt block, though the company insists the two-bolt blocks are more than sufficient for this power and rpm level. Each Demon 454 features a four-bolt block, though the company insists the two-bolt blocks The 400hp BBC combinations feature cast-steel cranks. The cranks are mag-checked for straightness and then ground (if necessary) and polished prior to assembly. Core cranks that don't pass inspection are discarded. A forged-steel crank is an option, but the added expense is deemed unnecessary at this power and rpm level. The 400hp BBC combinations feature cast-steel cranks. The cranks are mag-checked for strai The factory connecting rods are resized, polished, and treated to a rod bolt upgrade. According to Demon Engines, the company has run the factory connecting rods successfully at more than 700 hp and 7,000 rpm. An aftermarket rod is an option for those looking to add heavy doses of nitrous or boost. The factory connecting rods are resized, polished, and treated to a rod bolt upgrade. Acco The factory-cast, low-compression pistons are ditched in favor of a set of forged units from Probe Racing. Our test motor featured 0.030-over, 18cc domes that resulted in a pump-gas-friendly static compression ratio of 9.43:1 with our 118cc combustion chambers. Demon will also build the 454 with low-compression, flat-top pistons, though the power output will take a hit (of roughly 6 to 7 percent) thanks to a drop in compression to 8.1:1. The factory-cast, low-compression pistons are ditched in favor of a set of forged units fr Cam choice is actually up to the customer, but the most common cam is the Xtreme Energy XE268H (or equivalent) flat-tappet from Comp Cams. Milder cams can be used on towing applications, and wilder cams will offer more peak power at the expense of low-speed torque. The XE268H offered a 0.515/0.520 lift split, a 224/230 duration split (measured at 0.050), and a 110-degree lobe-separation angle. The duration specs offered good idle quality, and throttle response would be excellent on the street. Cam choice is actually up to the customer, but the most common cam is the Xtreme Energy XE Some may question the use of the much-maligned peanut-port heads on a performance motor, but there is no denying the results. Some may question the use of the much-maligned peanut-port heads on a performance motor, b 1 | 2 | » | View Full Article By Richard Holdener Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!