ATK Chevy 502 Marine Engine 515HP Base HP95

Item #22653 Brand:ATK Engines

Made in the USA
ATK Chevy 502 Marine Engine 515HP Base HP95
ATK Chevy 502 Marine Engine 515HP
* ** THIS ITEM IS TEMPORARILY OUT OF STOCK *** FREE SHIPPING on ATK Engines. This item ships directly from the manufacturer and is not available for store pickup. Some engines are made-to-order or can be backordered. Delivery can be delayed up to 5 to 6 weeks but typically ship within 2 weeks.
- +
Quantity: close
Free Shipping on this item


Looking to replace your existing or worn-out marine engine? Get this replacement engine for a Mercruiser 450hp 502ci marine engine. Designed to exceed expectations, this engine offers unmatched performance and lasting durability.

Engine Specifications:

  • Horsepower: 515 @ Crank - Estimated prop power 450HP
  • Torque: 570 @ Crank - Estimated prop power 500TQ
  • Block: Dart Big M 9.8 4 Bolt Main 1pc Seal
  • Bore/Stroke: 4.470 x 4.000
  • Displacement: 502 C.I.D.
  • Crankshaft: Scat Nodular Iron 4.000" Stroke Externally Balanced
  • Connecting Rods: Scat 4340 Forged I Beam 6.385" ARP 8740 Bolts
  • Pistons: Forged
  • Piston Rings: Moly Rings
  • Compression Ratio: 8.9:1 Compression
  • Camshaft: Hydraulic Roller
  • Camshaft Specifications: 224/224 @050 .483in/.483ex 115LSA
  • Camshaft Bearings: Installed & Clocked to OEM Position
  • Cylinder Heads: Dart Iron Eagle Rect-Port 119cc/308cc 2.25/1.88
  • Freeze Plugs: Brass Installed & Sealed
  • Rocker Arms: Stamped Steel 1.7 Ratio
  • Oil Galley Plugs: Installed & Sealed
  • Oil Pan: OE 5qt.
  • Weight: 565

ATK specializes in muscle. With the highest quality internal parts and Dyno Proven combinations of every engine built, ATK is able to add the most bang for your buck and back it up with an industry leading warranty. Check out our three stages of performance Ford Engines: they are separated by level of dress.


ATK High Performance GM 502 515 HP Stage 1 Long Block Crate Engines


Engine Information:

• Oil Filter: Wix or K&N Recommended Per Your Application
• Fuel Delivery: OE MPFI System or Quick Fuel Carburetor 780cfm #HR-780-VS
• Intake Manifold: Stock Cast Iron Marine or Aftermarket Performance
• Fuel Injectors: Stock Injectors
• Spark Plugs: Autolite #AR3933
• Spark Plug Gap: .035''
• Harmonic Balancer/Damper: POWERBOND Externally Balanced 8" #PB1018-N
• Flex Plate / Flywheel: Externally Balanced
• Timing: 34-36 Degrees
• Water Pump: Per Application
• Firing Order: 1 8 4 3 6 5 7 2
• Exhuast: Reuse Factory Exhaust system
• Fuel Pump: Marine Electric Or 110GPH Mechanical
• Ignition: Stock Marine Grade

Disclaimer: The parts listed are ATK’s recommendations of parts to be used to obtain our power figures listed. Power figures can vary based on parts used by the end user. It is the customer’s responsibility to verify components will work for their application. Some modifications to the vehicle may be required using these and or other aftermarket parts.

Shipping Information

Shipping is free and lift gate will be provided.

Eastwood Offers Free Lifetime Technical Support

Click here for product SDS information

Attention California Residents - Proposition 65

Proposition 65 Warning WARNING - Cancer and Reproductive Harm -


Customer Reviews

Questions & Answers