As much as we liked the Demon low-buck 454, we couldn't wait to perform a few upgrades, including new heads, cam, and 1.7-ratio aluminum roller rockers. Westech's Ernie Mena jumped in to adjust the valves during our dyno session. As much as we liked the Demon low-buck 454, we couldn't wait to perform a few upgrades, in The phones rang off the hook when we covered the components and dyno testing of the low-buck 454 from Demon Engines in the Oct. '10 issue. Checking in at $2,650 outright (minus carburetor), the low-buck 454 from Demon Engines offered an attractive combination of power and pricing. Bypassing the stock replacement and wrecking yard motors, the mill offered a minimum of 400 hp for just less than three large outright and required no core exchange. Even more impressive was the fact that the 400 hp came with a peak torque reading of 542 lb-ft. In fact, torque production exceeded 500 lb-ft from 2,800 rpm to 4,600 rpm, making this big-block a real thumper and ideal for a variety of different applications, including a performance street machine, a truck, or even an RV. Despite all this motor had going for it, we couldn't help but wonder what it might be like with a few performance upgrades. According to Demon Engines, even with a cast crank and factory rods with a bolt upgrade, the short-block will withstand considerable punishment. No way, you say? Not without a steel crank and forged rods! Check out part three when we add a low-buck turbo kit to the mix-but for now we will concentrate on upgrading the low-bucker with a few simple bolt-ons. The original 454 from Demon Engines featured a static compression of 9.4:1, peanut-port heads, and a mild hydraulic flat-tappet cam. The combination was good for 445 hp and 542 lb-ft. The original 454 from Demon Engines featured a static compression of 9.4:1, peanut-port he The three most important power producers in any combination are the heads, cam, and intake. A close examination of this engine reveals that upgrading at least two of these components will yield significant dividends. Since it was already blessed with a dual-plane intake from Procomp, we set our sights on replacing the peanut-port heads and mild Xtreme Energy cam. As it turned out, our choice of cylinder heads required replacement of the Procomp intake, but more on that later. First up was the camshaft. Out came the XE268H cam from Comp Cams to make room for a slightly wilder XE284H. Our hope was that the new cam profile would shift the torque curve higher in the rev range, thus producing more peak power. At the same time, we couldn't help but hope that the gains would result in only minimal trade-off in low-speed power. Though more than adequate for the 400 to 450hp range, our three-tiered power package included removing and replacing the peanut-port heads. Though more than adequate for the 400 to 450hp range, our three-tiered power package inclu When it comes to cylinder heads, just about any performance aftermarket head represented a significant step up in flow and power potential compared with the factory truck heads. Ideally suited to the 400 to 450hp level, the peanut-port heads are a significant restriction. They were replaced with a set of Profiler heads from Dr. J's Performance. The Profiler heads offered a number of important upgrades, including lightweight aluminum construction and a significant increase in airflow. Lifting a set of iron big-block heads is no picnic, so it should come as no surprise that replacing them with their aluminum counterparts offers a serious weight reduction. On the all-important power-to-weight scale, less weight is the same as more power. Thus, replacing the iron with aluminum heads offers a power gain irrespective of the additional airflow. Naturally, we did not choose the Profiler heads on weight alone; we were much more interested in their impressive flow figures. The Profiler heads also feature a five-angle valve job, a 5/8-inch-thick deck surface, and 0.250-inch raised exhaust ports. They came with CNC combustion chambers and a valvespring package designed for our sub 0.600-lift hydraulic flat-tappet cam, all for less than $2,000. The mild cam originally supplied in the low-buck 454 was also removed to make room for a stouter stick. The mild cam originally supplied in the low-buck 454 was also removed to make room for a s Keeping things simple and inexpensive, we selected another Xtreme Energy hydraulic flat-tappet cam from Comp Cams. Where the XE268H offered 0.515/0.520-inch lift and a 224/230 duration split with a 110-degree lobe-separation angle, the more aggressive XE284H stepped up things with a 0.574/0.578-inch lift, a 240/246 duration split, and the same 110-degree lobe-separation angle. New Comp hydraulic flat-tappet lifters (PN 812) were also part of the equation. Keeping things simple and inexpensive, we selected another Xtreme Energy hydraulic flat-ta Prior to installation, the new flat-tappet cam was liberally coated with moly-based assembly lube. The bottom of each lifter was likewise coated. This procedure helped prevent lifter and/or cam wear during break-in. Prior to installation, the new flat-tappet cam was liberally coated with moly-based assemb Using a combination of 290cc intake ports and 2.30-inch valve sizing, the Profiler heads from Dr. J's offered intake flow that peaked at 368 cfm at 0.700 lift. The 119cc combustion chambers matched that of the stock chambers on the peanut-port heads to maintain the 9.4:1 static compression ratio. Using a combination of 290cc intake ports and 2.30-inch valve sizing, the Profiler heads f The double-roller timing chain was retained, making sure to line up the timing dots with the piston at TDC. The double-roller timing chain was retained, making sure to line up the timing dots with t Supplied by Dr. J's, the Profiler heads featured a valvespring package suited to our hydraulic flat-tappet cam profile. Note also the guideplates designed to accept 3/8-inch pushrods. Supplied by Dr. J's, the Profiler heads featured a valvespring package suited to our hydra The exhaust side was equally impressive, with the 78cc port and 1.88-inch valves offering 268 cfm at the same 0.700 valve lift. The exhaust ports were raised 0.250, but the flanges were rolled 2 degrees to improve header/chassis fitment. The exhaust side was equally impressive, with the 78cc port and 1.88-inch valves offering Though it's not necessary with the spring pressure employed with this flat-tappet cam, we replaced the 5/16-inch pushrods with 3/8-inch Magnum units from Comp Cams. The pushrod lengths were unchanged 8.250/9.250. Though it's not necessary with the spring pressure employed with this flat-tappet cam, we Since turbo boost was in the very near future, we elected to replace the stock head bolts with a set of ARP head studs. The Profiler heads received a fresh set of Fel-Pro 1017 head gaskets. Since turbo boost was in the very near future, we elected to replace the stock head bolts 1 | 2 | 3 | » | 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!