Wow, the guys at Arias have done it again. Just when it looked like the world of cool bolt-ons and crate engines couldn't get any better, the famed Arias Hemi-Chevy surfaces in street trim. Yes, the same basic package that powered those awesome Top Fuel cars back in the day is again offered, but now with slightly more civil manners. Basically, two main packages of the Arias Hemi-Chevy are offered: a complete cylinder-head kit to bolt to your own big-block Chevy, or a 540ci Hemi-Chevy Big Block crate engine to stuff in your engine compartment. And a bigger 572 engine may be on the way. But before we get too deep into the details, here's a little Hemi-Chevy history.
During the late '60s, when guys in white coats were building rockets, a machinist named Nick Arias Jr. was toiling long hours in his Gardena, California, shop. Unlike the scientists aiming at the moon, Arias' target was designing the world's first non-Chrysler Hemi-headed big-block Chevy to thrust cars and boats across the earth at lightning speed. Soon the engine came to life, and the Arias Hemi big-block Chevy was successfully powering many offshore power boats and Top Fuel cars. Throughout the '70s, Arias elected a man by the name of Steve Montelli, of Gardena's Montelli Racing Engines, to further research and develop the 8.3- and 10L Hemi Big Block Chevy and to promote the engine at numerous Top Fuel, drag, and power-boat racing events across the U.S. The long hours paid big dividends for Arias and Montelli as the Arias HemiSpherical Big Block Chevy, with its tremendous cylinder-head breathing and combustion capabilities, grabbed many racing records in Top Fuel, Bonneville, and especially offshore power-boat racing.
Today, the Arias HemiSpherical Chevy is available again. But what's especially exciting now is that, unlike its predecessor, which was engineered as a race-only item, the new HemiSpherical Chevy is designed to deliver mammoth power in street cars on pump gas. These new street-version cylinder heads have been improved with superior valvetrain hardware, a better 1.75:1 rocker ratio, relocated rocker-arm shafts, and redesigned and lengthened exhaust rocker arms that eliminate the need for the older, cumbersome third pushrod used on the earlier versions.
Additionally, multiple options are offered, including superchargers and upgraded blocks (for crate engines), and many more are on the way. It's all up to the way you want your package delivered. Because of the spanning and unique cylinder heads, installing a Hemi-Chevy into almost any car will take a good amount of fabrication, and custom headers are a must.
Although the horsepower and torque capabilities are huge, the combos offered are tamed down so that the engines can operate on the street. Some of the preliminary tests we've seen for street use have produced over 800 lb-ft of torque and almost 1,000 horses. With one of these in your ride, just think how cool it will be to pop your hood and watch your buddies gawk at the big set of Arias Hemi-Chevy heads mounted atop a big-block Chevy. What's more, imagine the rush you'll experience when you nail the throttle.
The Arias HemiSpherical Big Block Chevy is currently designed to fit to a tall-block. Arias plans to offer the kit for a 9.80-inch deck soon. The current complete head kit is available for $11,900 and includes
* Two cast-aluminum Hemi-Chevy cylinder heads w/stainless valves, 2.375-inch intake, 1.940-inch exhaust, titanium retainers, spark-plug tubes, and seals
* Rocker-arm assemblies: billet rocker stands w/hardened-steel step washers; centerless ground, heat-treated rocker shafts; investment cast-steel rocker arms, 4130 alloy heat-treated shot-peened; flame-hardened exhaust tips, roller-tipped intakes, Timken needle bearings and Manton rocker adjustment screws, H-13 material
* Manton 31/48-inch pushrods, 0.120-wall, tool-steel tips
* Arias cast-aluminum valve covers w/fill caps
* Hemi-Chevy header flanges
* Arias custom cast-polished-aluminum thermostat manifold and polished adjustable water neck
* Hemi-Chevy billet valley cover
* Hemi-Chevy tunnel-ram dual-carburetor manifold
* Hemi-Chevy cylinder-head hardware kit
* Raised-port tunnel-ram manifold w/dual quad plenum for 10.20- and 9.80-inch-deck big-block Chevys
* Blower manifold w/adaptor plate for single quad for 10.200- and 11.200-inch-deck block (additional components)
* Blower manifold for 10.200- and 11.200-inch Hemi-Chevy crate engines
Let it Flow
The Arias Hemi-Chevy big-block head produces its big power by flowing large amounts of air through a very efficient combustion chamber. Because the camshaft yields 0.671 inch lift, the engine will benefit from the excellent flow numbers above 0.600 inch lift.
To date, Arias doesn't have any final power numbers on the Hemi-Chevy street packages, but they do have a preliminary test using a 540 big-block with 8 pounds of boost from an 8-71 supercharger. Although the highest power recorded on this dyno pull reached 963 hp, it appears that it would have surpassed this level if the dyno operator had tested well past the 6,500-rpm mark. Also notice that this engine developed over 800 lb-ft of torque from 5,000 rpm. Arias tells us it will have data reflecting full dyno tests in the near future for a variety of packages.
Create Full Of Power
The $21,100 Arias HemiSpherical Big Block Chevy 540 carbureted crate engine includes the following components
* Merlin III block, 10.200-inch tall-deck, 4.500-inch bore, 11/42-inch Chevy head bolt with 10-bolt layout, finish machined
* Eagle big-block Chevy crankshaft, 4.250-inch stroke
* Eagle big-block Chevy H-beam 6.535-inch connecting rods, with ARP-2000 bolts
* Arias custom Hemi-Chevy forged pistons, 10:1 compression, 0.990-inch pin and ring set
* Herbert solid roller cam
* Isky solid roller lifter set
* Pro-Gear timing set
* Clevite main and rod bearings
* Milodon timing cover
* Milodon water pump
* Milodon Hemi-Chevy oil pan
* Pro-Comp electronic ignition
* Taylor ignition wire set
* Melling high-volume oil pump
* Pioneer harmonic damper
* SCE copper Hemi-Chevy engine gasket set
* Quick Fuel or Barry Grant carburetors
* Lawson hardware engine kit
* Manton pushrods