The Chevy 604 Crate Engine is a high-performance 5.7L V8 racing engine designed for dirt and asphalt circle track racing. It is part of Chevrolet Performance’s CT400 line, widely used in crate racing series like DIRTcar, IMCA, and other sanctioned events. Known for its durability, affordability, and consistent power output, the 604 engine is a popular choice for racers looking for a reliable sealed engine package.
Chevy 604 Crate Engine Specifications
Here is a breakdown of the technical specifications of the Chevy 604 crate engine:
Chevy 604 Crate Engine Specifications
| Specification | Details |
|---|---|
| Engine Code | CT400 (PN 19318604, 88869604) |
| Displacement | 5.7 L (350 cubic inches) |
| Configuration | V8 |
| Block Material | Cast Iron |
| Cylinder Head Material | Aluminum |
| Bore x Stroke | 4.00 in x 3.48 in (101.6 mm x 88.4 mm) |
| Compression Ratio | 9.6:1 |
| Valvetrain | Hydraulic Roller Camshaft, OHV, 16 valves |
| Camshaft Lift (Intake/Exhaust) | 0.474 in / 0.510 in |
| Camshaft Duration @ 0.050″ (Intake/Exhaust) | 224° / 230° |
| Fuel System | Carbureted (750 CFM Recommended) |
| Aspiration | Naturally Aspirated |
| Ignition System | HEI Distributor |
| Horsepower | 400 hp @ 5,500 rpm |
| Torque | 400 lb-ft @ 4,500 rpm |
| Oil Capacity | 8 quarts (with filter) |
| Recommended Oil Type | 15W-50 Racing Oil |
| Cooling System | Liquid-cooled |
| Fuel Type | 110+ Octane Race Fuel (No Pump Gas) |
| Firing Order | 1-8-4-3-6-5-7-2 |
| Recommended Carburetor | Holley 750 CFM (4150-style) |
| Weight | ~430 lbs (dry) |
The 604 crate engine is a dyno-tuned and sealed engine from Chevrolet Performance, ensuring a level playing field in racing competitions. The high-flow aluminum heads and hydraulic roller camshaft provide excellent power and torque while maintaining durability.
Engine Configuration and Components
Block and Bottom End
The 604 engine block is a high-nickel cast-iron small-block V8, designed for strength and longevity under high-performance conditions.
- Four-bolt main caps provide extra bottom-end strength.
- Forged steel crankshaft ensures durability in high-RPM applications.
- Powdered metal connecting rods offer a balance of weight and strength.
- Hypereutectic aluminum pistons reduce expansion and increase longevity.
Cylinder Heads and Valvetrain
The Chevy 604 crate engine features high-flow aluminum cylinder heads, which improve cooling efficiency and combustion chamber design.
- Aluminum heads reduce weight compared to iron heads, improving overall vehicle handling.
- 2.00-inch intake valves and 1.55-inch exhaust valves allow for improved airflow.
- Beehive valve springs enhance valve control at high RPM.
- Hydraulic roller camshaft provides smooth power delivery and reduced friction.
Fuel System and Carburetor
Unlike modern fuel-injected engines, the 604 crate engine is designed for carbureted setups. Chevrolet Performance recommends using a Holley 750 CFM four-barrel carburetor for optimal performance.
- Mechanical fuel pump required (electric pumps not allowed in some series).
- No electronic fuel injection (EFI) permitted in most sanctioned races.
- 110+ octane racing fuel recommended for optimal combustion.
Ignition System
The 604 engine uses an HEI (High-Energy Ignition) distributor for consistent spark delivery.
- Proper ignition timing is crucial for peak performance.
- A racing-specific ignition coil is recommended for high-RPM stability.
- MSD ignition systems are commonly paired with the 604 engine.
Recommended Maintenance and Service Intervals
Proper maintenance is critical to maximizing the lifespan and performance of the Chevy 604 crate engine.
Oil and Filter Changes
- Interval: Every 2–3 races or 500 miles
- Recommended Oil: 15W-50 Racing Oil (Synthetic preferred)
- Oil Capacity: 8 quarts (with filter)
Valve Lash and Rocker Arm Adjustment
- Interval: Every 500–1,000 miles
- Recommended Procedure:
- Check pushrod and rocker arm condition.
- Ensure proper preload on hydraulic lifters.
Carburetor and Fuel System Maintenance
- Interval: Inspect and clean after every race.
- Recommended Fuel Type: 110+ octane racing fuel.
- Preventative Measures:
- Drain carburetor after races to prevent fuel varnish buildup.
- Use fresh race fuel to avoid detonation issues.
Cooling System Maintenance
- Radiator Flush: Every 5 races or 1,500 miles
- Water Pump Inspection: Check for leaks and bearing wear.
- Use Distilled Water + Racing Coolant Additive (No antifreeze in racing applications).
Spark Plugs and Ignition System
- Interval: Every 1,500–2,000 miles
- Recommended Spark Plugs: NGK R5671A-7 or equivalent
- Check ignition timing regularly to maintain performance.
Timing Chain Inspection
- Interval: Every 5,000 miles or whenever performance drops.
- Upgrade Consideration: Some racers opt for billet timing sets for increased durability.
Compression and Leak-Down Test
- Interval: Every 10 races or 3,000 miles
- Purpose: Identify potential ring wear, valve leakage, or head gasket issues.
4. Common Issues and Reliability
The Chevy 604 crate engine is designed for durability, but some issues can arise:
- Valve Spring Wear – Beehive valve springs need periodic replacement after 1,500–2,500 miles.
- Oil Consumption – Some 604 engines consume a small amount of oil under high RPM conditions.
- Overheating – Improper cooling system maintenance can lead to overheating in long races.
- Timing Chain Stretch – Stock timing chain may need replacement after extended use.
Despite these issues, the 604 crate engine is highly reliable when properly maintained.
The Chevy 604 Crate Engine is a proven performer in dirt and asphalt racing, offering 400 horsepower, excellent torque, and strong reliability. It remains a cost-effective choice for racers, thanks to its sealed design and standardized competition rules.
By following strict maintenance schedules, racers can maximize the performance and longevity of their 604 crate engine, ensuring consistent results on the track.
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