Win This Engine in the Holley 383 Small-Block Chevy Giveaway!
For their latest giveaway engine, Holley and engine builder Prestige Motorsports decided to go back to their roots for an old-school build with a modern twist. The small block Chevrolet is like the Godfather of modern performance engines. There’s probably been more of them made in a greater variety of configurations than any other two internal combustion engine designs in history combined.
Early on, one of the most popular – and most effective – techniques for squeezing more power out of a stock 350 Chevy was to drop in a crankshaft from the truck-oriented 400-ci small block to increase the stroke from 3.500 inches to 3.750. The 400 wasn’t desirable as a performance engine because its 4.125-inch diameter pistons left the cylinder bores too thin. But the thicker cylinder walls of the 350 combined with the additional quarter inch of stroke from the 400’s crank was a match made in heaven.
So, the popular combo became a 350 with the cylinders bored 0.030 over to 4.030 inches and the 3.750-stroke crank, which bumped the displacement to 383 cubic inches. That left plenty of bore thickness to handle lots of horsepower. Besides the extra cubic inches to help make power, the 383 configuration also benefits from the added piston speed that comes with the extended stroke. That’s because an engine with a longer stroke will move the piston farther than one with less stroke. In the lower rpm range the longer-stroke engine will create vacuum in the combustion chambers more quickly, pull harder on the intake, and have more pep as soon as you get into the throttle.
For Holley’s latest sweepstakes giveaway, they decided to go with a classic engine combo, punching out a Chevy small block with a 4.030 bore and 3.750 inches of stroke to make the famous 383.
For this build we’re honoring that old hot-rodders trick to craft a classic 383 small block. But as always, we’re doing it with a handful of modern upgrades to help the engine make even more power, live longer, and just be more fun to drive. And the masterminds at Prestige put together a parts package that won’t break the bank if you want to replicate this build on your own.
Of course we’re using many parts from the Holley catalog, but we also received support from Eagle for the crankshaft and connecting rods, DSS for the pistons, Moroso for the oil pan, Edelbrock Group for valvetrain components, and ARP for fasteners. Everything came together fantastically, and that proved out when the engine punched way above its weight class on the dyno, making 510.3 horsepower running pump gas.
If you think this engine would go great in your ride, you have until October 1, 2024 to get your entry in here: Holley 383 Small-Block Chevy Giveaway
There’s no cost to enter and the winner will be notified sometime around October 7. Good luck!
This is a build to maximize power (and fun) without breaking the bank. So, the block chosen is a factory Chevy unit pulled out of either a car or truck. After passing a battery of checks, Prestige Motorsports machined it back up to spec while also knocking out the cylinders 0.030 over, and now it’s good to go.
This is a two-bolt main block, but with our 500-horsepower target that’s no big deal. The crankshaft is a quality 4140 steel forging from Eagle, with 2.100 rod journals and a stroke of 3.750 inches.
This is one of the newer one-piece rear main seal blocks. The one-piece seal is less likely to leak over the long haul, but it does require a different crank and oil pan than the old-school blocks with the two-piece seal.
For the rotating assembly, we’re sticking with Eagle for the connecting rods. These are squeezing in the maximum length for a standard-deck block at 6.000-inches from center to center to optimize the rod-stroke ratio. The pistons are DSS slugs custom made for this build. They have a slipper skirt for minimum drag as they travel up and down the cylinder bores. The 4032 aluminum forgings are quite strong and have a flat top with a 1.125-inch compression height.
To make 3.750-inches of stroke fit into a standard 350 small block, the block needs to be notched along the oil pan rail to keep the big end of the connecting rods from crashing into the block. You can see how the guys at Prestige did it here. It’s a simple process that can be done with a die grinder. Just mockup the crank and a rod or two and mark the block where the rod contacts the block as you try to rotate the crank. If you have a good set of rods like these from Eagle, it’s usually just the head of the rod bolt that you will have to clearance for.
Up top, the pistons are only about 0.004 of an inch lower than the deck of the block at TDC to maximize squish.
This steel oil pan from Moroso is designed to provide extra capacity for oil in the sump. This helps keep the oil cooler and reduce the chance of the oil pump pickup getting uncovered. The rear sump also means it will fit in a wide variety of different vehicles without modification.
The camshaft is a hydraulic roller from Comp Cams. It’s ground with 240 degrees of duration for the intakes and 252 for the exhausts – both at 0.050-inch tappet lift. Tappet lift is 0.380 for the intakes and 0.370 for the exhausts.
The cylinder heads are Prestige Motorsports’ own aluminum castings. The intake runners are sized at 180cc while the combustion chambers are 64cc. That makes the final combustion ratio 10.5:1.
Assembler Cody McCleary torques the ARP head bolts to 70 lb-ft to secure the heads to the block.
A set of Comp Cams’ Ultra Gold aluminum rockers will activate the valves. These aluminum rockers reduce the overall mass of the valvetrain while also being quite stiff, for maximum valve control. They sit on big 7/16-inch rocker studs and have slightly more rocker ratio than stock at 1.6:1. That will make the gross valve lift 0.608 for the intakes and 0.592 for the exhausts.
To help move maximum amounts of air into the combustion chambers, Prestige chose a single-plane intake manifold from Holley. This aluminum intake is designed to work best between 2,500 and 7,500 rpm and it has bosses cast into it for port fuel injection.
At first glance this looks like a carbed setup. And at second glance it looks like a Holley Sniper Stealth throttle body camouflaged to seem like an old-school carburetor. But it's actually neither – this is one of Holley’s Terminator X Stealth Air Valves. It’s capable of flowing 950 cfm and functions as a throttle body, so we can have modern port fuel injection while still giving the small block that old-school feel.
Here’s the setup complete with the Holley fuel rails installed on the manifold and the Holley Dual Sync distributor, which provides the Terminator X ECU information on both the crankshaft and cam positions. Check out the sweet routing setup to protect the plug wires from touching the headers.
The cast valve covers from Holley are finned with a cool script to complete that old-school look.
Holley’s mid-mount accessory drive system includes an alternator, power-steering pump, and AC compressor, all spun by a low-drag serpentine belt setup. The setup mounts to a custom water pump casting that eliminates finicky brackets.
On the dyno, our 383 small block ran like a champ. While burning pump gas, it made peaks of 510.3 horsepower at 6,100 rpm and 470 lb-ft of torque at 5,000. The combination of great power and strong torque throughout the pull will put a smile on the face of anyone who appreciates performance.
