How to Identify a Honda Engine by Its Code

Introduction

Honda engine codes might look like a random mix of letters and numbers, but they actually contain useful information about the engine’s series, displacement, and origin. Whether you’re swapping an engine, buying a used Honda motor, or just geeking out on Honda specs, knowing how to decode an engine code is essential.

This guide will break down how to read Honda engine codes, what they mean, and where to find them on the engine.

1. Understanding Honda Engine Codes

Honda engine codes typically follow this format:
[Letter(s)][Number(s)][Suffix]
Example: B18C5 (from an Integra Type R)

Each part of the code tells you something specific:

  • Letter(s) (B, K, J, etc.) → Engine series (e.g., B-series, K-series)
  • Numbers (16, 18, 20, etc.) → Approximate engine displacement in liters (1.6L, 1.8L, etc.)
  • Suffix (A, B, C, etc.) → Engine variant (VTEC vs. non-VTEC, market region, performance level)

Examples of Common Honda Engine Codes:

Engine CodeDisplacementVTEC?Notes
D16Y81.6LYesFound in Civic EX (SOHC VTEC)
B18C51.8LYesIntegra Type R (DOHC VTEC)
K20A22.0LYesRSX Type S (DOHC i-VTEC)
J32A23.2LYesAcura TL Type S (V6)
L15B71.5LYesTurbocharged Civic engine

2. Where to Find Your Honda Engine Code

Honda engine codes are stamped onto the engine block. The location varies depending on the engine series:

  • B-Series & D-Series → On the front of the engine block, near the transmission.
  • K-Series → On the driver’s side of the block, near the starter.
  • J-Series (V6 engines) → On the front of the block, near the transmission.
  • L-Series (Turbo 1.5L) → On the front of the engine block, visible from above with intake tubing removed.

📌 Tip: The engine code is usually located on a flat, raised section of the block and is easy to read once you clean off any grime.

3. Breaking Down Honda Engine Code Suffixes

The suffix letter(s) after the numbers can tell you important details about the engine variant:

  • A1, A2, A3, etc. → Different versions of the same engine (often market-specific)
  • B → Typically indicates a lower-performance version (e.g., B18B1 is a non-VTEC engine, while B18C1 is VTEC)
  • C → Often used for performance variants (e.g., B18C1, B18C5 for GSR and Type R engines)
  • Z → Found on some newer or sometimes VTEC Honda engines, including hybrid and turbo models

Example: K20A2 vs. K20Z3

  • K20A2 → Found in RSX Type S, higher revving performance engine.
  • K20Z3 → Found in 8th-gen Civic Si, slightly different head design and ECU mapping.

4. Identifying JDM vs. USDM Honda Engines

Many enthusiasts import JDM (Japanese Domestic Market) engines because they often have higher power output and fewer emissions restrictions.

How to Spot a JDM Engine:

✅ The engine code does NOT have a number after it (e.g., K20A, B16A → These are JDM-spec).


✅ JDM engines often have higher compression ratios and more aggressive cam profiles.


✅ USDM versions usually have an additional number (e.g., K20A2, B16A3).

Example:

  • JDM B16A → 170 HP (higher compression, no number in code)
  • USDM B16A3 → 160 HP (found in Civic Del Sol VTEC, has number in code)

Note: There are some outliers that don’t quite make any sense, such as the ZC. The ZC is a D Series engine that can be SOHC or DOHC, VTEC or Non-VTEC, OBD0 or OBD1, so the stamp on the block doesn’t tell you a whole lot in this case.

5. Common Honda Engine Series & Their Uses

D-Series (Budget-Friendly & Reliable)

  • D15, D16 engines → Found in Civics, great for economy builds.
  • D16Z6, D16Y8 → SOHC VTEC options, good for mild performance.

B-Series (The Classic High-Revving Performance Engines)

  • B16, B18, B20 → DOHC VTEC and non-VTEC options for Civic & Integra.
  • B18C1 (GSR), B18C5 (Type R) → Higher-revving, high-performance engines.

K-Series (Modern Power & Efficiency)

  • K20A2, K20Z3, K24A2 → Found in RSX, Civic Si, TSX, great for swaps.
  • K24/K20 Hybrid (“Frankenstein” Build) → Uses a K24 block with a K20 head for best of both worlds.

J-Series (Honda’s V6 Performance Engines)

  • J32A2, J35A8, J37A1 → Found in Acura TL, RL, MDX, good for swaps in larger chassis.

L-Series (Honda’s Turbocharged Future)

  • L15B7 → 1.5L Turbo from the 10th-gen Civic, lightweight and efficient.

Conclusion: Why Engine Codes Matter

Knowing how to identify a Honda engine by its code helps you:

✅ Pick the right engine for a swap.

✅ Understand what you’re buying (avoid getting scammed!).

✅ Spot JDM vs. USDM engines.


✅ Learn about Honda’s engine history.