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Back in the May ’12 issue, in a story called “Big Heat”, we showed off the assembly of a factory block-based 496ci short-block, featuring the skills of Bryce Mulvey of Dr. J’s Performance in Anaheim, California. The idea was to put together a durable, yet simple big-block that we can test various parts on in future issues—something that can take multiple dyno pulls without a hiccup. What we came up with was a stock big-block Chevy stuffed with a forged crank from Scat that featured a 4.250-inch stroke, forged H-beam rods also from Scat, and a set of high-compression domed slugs from JE Pistons. With around 13:1 compression smashing against Brodix STS Race-Rite BB-2 heads, we hoped to make around 700 hp on the engine dyno. In this installment, Mulvey finishes up our 496ci using some super-durable parts from companies such as COMP Cams, Moroso, Brodix Cylinder Heads, and Quick Fuel Technology. COMP Cams was critical in getting this anvil together; dual valvesprings, titanium retainers, one-piece pushrods, and COMP’s Magnum rockers were all bolted into place, while companies like Moroso and Quick Fuel handled the oil system and carburetion. After engine builder Bryce... After engine builder Bryce Mulvey of Dr. J’s dropped the Scat rotating assembly into our stock big-block, he sealed it all up using a nicely baffled oil pan from Moroso. The baffle is definitely worth horsepower too, as it keeps oil from accumulating on the crank’s counterweights. If the short-block is considered the “meat”, then the “potatoes” of this engine is the STS BB-2 Race-Rite head and intake setup from Brodix. Most of the Brodix BBC heads feature exhaust ports that have been raised to improve flow, but for those who don’t want to go with custom headers, Brodix offers a Race-Rite option that features exhaust ports in the stock location, as well as some additional accessory holes in the ends of the heads. On the intake side at 0.700 lift, these heads flow up to 369 cfm, while the exhaust flows 267 cfm. At 0.600, they flow 359/251. Luckily for us, the COMP Cams roller bumpstick will make the most of our head’s airflow, as it features 0.714/0.710 of lift and 270/280 duration at 0.050. With a goal of 700 hp in mind, we followed Mulvey as he assembled the top end and strapped it to his DTS Powermark engine dyno for a day of wide-open throttle fun. Many years ago, head builders figured out that raising the location of the runners of a cylinder head could drastically improve flow characteristics. While raising the runners is great for ultimate power, it can add complications when it comes to header fitment, especially in a tight engine bay. For the racer, Brodix has one of the most extensive lists of cylinder heads we’ve ever seen, but they also have some killer heads for radical street cars. The Brodix Race-Rite line was introduced as a great way to make big power without needing special items, which was perfect for our “Big Heat” test mule: • Ends milled and drilled for accessories • Extra-thick rocker stands • Exhaust ports in stock location • Available in oval and rectangle ports • Direct replacement for cast-iron heads  With the heads bolted up,...  With the heads bolted up, it was time to determine the pushrod length. Because engine deck heights can vary depending on a few factors (e.g, block machining you may not be aware of), there are no “factory length” pushrods. Competent engine builders always measure for pushrods with the head and head gasket bolted down.  Mulvey came up with a pushrod...  Mulvey came up with a pushrod length right around 9.540 inches, which COMP Cams categorizes as PN 7756. These one-piece, 0.080-inch wall pushrods were perfect for our 496ci powerplant; they are affordable and extremely strong.  Although this engine won’t...  Although this engine won’t reach the rpm needed to really take advantage of a lightweight valvetrain, we opted for COMP Cams’ titanium retainers on this 496ci bullet. The idea is to get weight off of the valve, which can limit valve float and promote a quicker-revving engine.  In order to achieve proper...  In order to achieve proper valvespring height, Mulvey used COMP Cams’ spring seats, which are steel shims that get positioned under each spring to raise the height for ideal valvetrain geometry. Various thicknesses and diameters are available.  Slamming the valves shut on...  Slamming the valves shut on our “almost 500” engine are COMP’s dual valvesprings, PN 944-16. When the valves are closed, the springs feature 190 pounds of pressure when installed at 1.950, but Mulvey opted to install them at 1.900, which stiffened them to 235 pounds. With a nice spring rate of 743 lb/in, it made them perfect for our 6,700-rpm stormer.  Steel roller rockers from...  Steel roller rockers from COMP’s Pro Magnum line were used on this build, which feature a perfect mix of strength and durability. They feature roller bearings in a large trunion, as well as the tip. Unlike aluminum rockers, these Pro Magnums can actually be rebuilt.  A high-flow/volume oil pump...  A high-flow/volume oil pump from Moroso was able to lubricate our BBC’s valvetrain with ease. This shot was taken after Mulvey primed the pump and adjusted the valves on the dyno.  The rectangular intake ports...  The rectangular intake ports flow around 369 cfm at 0.700 lift on the intake side and 251 cfm on the exhaust side. At 0.600 lift they still move almost 360 cfm of intake and 267 cfm worth of exhaust. These heads also come in an oval-port configuration, but the flow numbers are different.  Because Brodix designed their...  Because Brodix designed their Race-Rite line with street cars in mind, these heads feature additional drilled and tapped accessory holes for things like air conditioning and power steering.  Sitting atop our 496ci powerplant...  Sitting atop our 496ci powerplant is a Brodix port-matched single-plane intake manifold, a four-hole tapered spacer from HVH, and Quick Fuel Technology’s 950-cfm 4150-style carburetor.  What readers may not know...  What readers may not know is that Quick Fuel’s carburetors are constructed from mostly aluminum parts, unlike other carb brands. This 950 cfm with annular boosters from QFT performed great out of the box and helped us reach our goal.  As noted earlier, we were...  As noted earlier, we were looking to get around 700 ponies out of our stock-block behemoth using these carefully selected parts. The heads, cam, and carburetor are all relatively mild components, and we could easily see this engine in a bulletproof bracket car that gets raced every week. On Dr. J’s DTS engine dyno, we were pleased to see our goals reached, only to steam past our expectations. By 5,700 rpm, we were already snaking past our goal, and 1,000 rpm later, we saw 750.1 flash on the screen. This was also with minimal tuning, we suspect another 20 hp if we messed with oil weights and carb spacers. Not a bad combination for the average power-hungry gearhead. Now if we were really crazy we’d spray the daylights out of it with nitrous, maybe in a future issue?
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