565 To Go: How Summit Racing’s 565 Big Block Anvil Came Together

The Dart Sportsman block comes fully machined, including deburring and finish plate-honing and decking. Even the cam bearings and freeze plugs are installed. The lifter bores accept .903-inch diameter roller lifters (stock big Chevy lifters are .842-inch). The larger lifters allow the use of more aggressive cam profiles without sacrificing reliability. That boss in the center is for one of the blind cylinder head studs; there are two on each head.

After tapping the last rod and piston assembly into its bore, Marco torques the rod bolts to 75 ft.-lbs. Want to know what the biggest difference between the Sportsman block and Dart’s Big M block is? The Sportsman uses these ductile iron caps, while the Big M gets steel caps.

900 horsepower + oil starvation = bad juju. That’s why Summit Racing specified a Moroso billet aluminum high volume, high pressure oil pump for the 565. It features an efficient spur gear drive, anti-cavitation slots and feeder grooves, and an enlarged bypass area in the housing that bleeds oil back to the inlet side of the pump.

This photo gives you a good look at the Eagle Specialties crankshaft. Forged from 4340 steel, the crank is heat treated, stress relieved, and shot peened. It is crossdrilled and has chamfered oil holes to improve main bearing oiling. A .125-inch radius on the main and rod journals prevents stress cracking. The crank and rods are available from Eagle fully balanced for use with the JE pistons used for this build, saving you a trip to the machine shop.

Marco degrees in the COMP Cams Drag Race Series roller cam. The solid roller stick specs out at .277 degrees/.292 degrees duration @ .050” (.310 degrees/.330 degrees advertised) and .800 inches of valve lift. The cam is “4/7” grind—cylinders 4 and 7 switch places in the firing order. The idea is to add a few extra high-rpm horsepower and more importantly, reduce crankshaft harmonics for longer engine life and reliability.

A Summit aluminum timing cover is bolted into place. The die-cast, one-piece cover has extra-thick gasket rails for rigidity and optimum sealing. Underneath the cover is a Cloyes Hex-A-Just double roller timing set. The Hex-A-Just features billet steel gears and the ability to adjust timing virtually anywhere, up to +/- 6 degrees.

Care to guess whose cylinder heads studs were used? The ARP Pro Series head studs are rated at 190,000 psi tensile strength—not much short of a nitrous pop or blower meltdown will hurt them. ARP assembly lube is used on the threads.

This Milodon Drag Race oil pan is a popular wet sump pan. The six quart pan features a full length louvered windage tray and double trap doors to control oil and maintain consistent oil pressure. That frees up horsepower.

Marco lowers a Dart Pro 1 aluminum cylinder head onto the block. The heads feature rectangular intake ports with CNC-machined 355cc runners, CNC-machined 138cc exhaust runners, and CNC-machined 199cc combustion chambers. The Pro 1s come fully assembled with 2.300-inch intake/1.880-inch exhaust stainless valves, 1.625-inch dual valve springs (good to .720 inches of valve lift), 10-degree locks and titanium retainers, valve seals, and guideplates. Cometic multi-layer steel (MLS) head gaskets seal the Pro 1s to the block.

Here’s how the blind head studs attach to the block. The aluminum retention blocks are included with the Pro 1 cylinder heads.

If Crower stainless steel shaft mount rocker arms sound like overkill, consider the tremendous abuse the valvetrain sees at 7,000 rpm. Shaft rockers won’t flex like stud mount rockers do—and Crower’s stainless shaft rockers are as close to bulletproof as you can get. That means more stable valve timing and longer valvetrain life. The 1.7 ratio rockers are a bolt-on for the Dart Pro 1 heads—no machine work is required.

The Dart air-gap style intake manifold insulates incoming air and fuel from engine heat, has optimized runner cross-sections to maintain air/fuel charge velocity, and extended runner dividers to help equalize port lengths for better air/fuel distribution to the cylinders. The single plane manifold comes CNC port-matched to the Pro 1 cylinder heads. A pair of Dart cast aluminum valve covers finish off the long block.

The 565 initially got this Quick Fuel QFX Series carburetor. The 1,250 cfm carburetor features a die-cast aluminum main body and fuel bowls. The main body has raised 1.900-inch diameter venturis to help boost airflow and midrange torque. Other features include billet aluminum annular boosters; CNC-machined billet aluminum metering blocks with screw-in idle feed, emulsion, and intermediate bowl/feed discharge restrictions; and external linkage with four throttle ratio adjustments (25 percent, 40 percent, 50 percent, and 1:1) to set the primary throttle opening rate when the secondaries kick in. Each Quick Fuel carb is hand-assembled and engine dyno tested.

MSD supplied one of its Flying Magnet crank triggers and this Pro-Billet Crank Trigger distributor. Since the crank trigger takes care of ignition timing, the distributor’s job is simply to route spark to the plugs—the only component underneath the low profile cap is the rotor. Other features include a CNC-machined billet aluminum housing, an oversized steel shaft and Rynite base to handle high voltage, and dual O-rings at the housing base to prevent oil leakage.

Big cubic inches need lots of cooling. This CSR electric water pump delivers 35 to 37 gallons of water per minute and draws just 5.8 amps of electricity to do it. The pump weighs a mere 5 1/2 pounds and features a CNC-machined billet aluminum housing, a stainless steel shaft, an RF suppression circuit, and a removable center section that allows access to the timing cover. CSR also supplied a Platinum Pro high torque starter and a SFI 29.1-approved Torque Master steel flexplate.

The TCI Rattler looks like a harmonic damper, but don’t let TCI hear you call it that. The company calls the Rattler a vibration absorber—it utilizes nine internal rollers to literally absorb torsional crank vibration and twist throughout the engine’s rpm range. That means a smoother running engine and longer crank and bearing life.

One 565-cubic-inch racin’ engine, ready for a trip to the dyno at Ross Racing Engines. Sharp eyes most likely noticed the Moroso vacuum pump on the passenger side cylinder head. The pump’s mounting bracket is designed for use with a front motor plate, but space issues forced Marco to mount the pump on the head and cut the crank mandrel to get the accessory pulleys to line up.

The first power pull showed the 565 clearly wanted more fuel, so Ross and Tony Lombardi progressively rejetted the Quick Fuel carburetor. #97 jets on primary and secondary sides did the trick—the 565 made 920 peak horsepower at 7,500 rpm, and 726 foot-pounds of peak torque at 6,300 rpm. The torque curve was especially impressive—over 600 ft.-lbs. from approximately 4,600 rpm up to redline.

Convinced the 565 had more power lurking within its cast iron guts, Summit Racing tapped Willy’s Carburetors for one of the company’s Holley Dominators. Rated at 1,250 cfm, the carburetor features patented metering blocks with adjustable, external metering valves. A simple turn of a hex head knob lets you rejet both primary and secondary sides without the hassle of removing the fuel bowls.

Here’s a closeup of the metering valve knob. There are five settings total, each representing two Holley jet sizes (the center is baseline). The two settings to the left of center add more fuel; the two settings to the right lean out the air/fuel mixture. The metering valves are replaceable—Willy’s offers valves that equate to #60-, #70-, #80-, and #90-series Holley jet sizes.

How did the 565 take to its new air and fuel mixer? Quite nicely, actually. Two clicks to the left on the metering blocks (with #90 series valves) and out came the power—942 horsepower at 7,200 rpm and 746 ft.-lbs. of torque at 6,200 rpm. Peak to peak, the Willy’s carburetor added a touch over 21 horsepower and 20 ft.-lbs. of torque.

Dyno results are cool and all, but the proof is in the time slip. Marco bolted the 565 into his IHRA Top Dragster and took it to Quaker City Raceway, where he won class in the track’s Saturday night program. At a test and tune at Summit Racing Equipment Motorsports Park, the 565 rewarded Marco with a 7.48 second/176.60 MPH pass. And at an 1/8-mile, run-what-ya-brung Quick 16 event, Marco gave the big block a 250-horsepower shot of nitrous and qualified third with a 4.44/157 (approximately 6.85/190 in the quarter-mile). “I was competing against some serious players with really big cubic inch engines,” Marco told us. “People were impressed that my “little” motor ran as hard as it did.” There’s no higher praise for a race engine than that.