H22A engine and gearbox

Engine Complete engine and transmission swap Verified Modification Required

Compatibility Overview

Source Vehicle

Prelude

Generation: BB (4th/5th gen)

Years: 1992-1996 (JDM H22A)

Target Vehicle

Civic

Generation: EG

Years: 1992-1995

Installation Difficulty

Easy Basic tools
Moderate Some experience
Difficult Skilled work
Expert Professional

Reference

H22A specs → EV specs → LEA-MF5 specs → LEA-MF6 specs → LEA specs → PDE-1 Cylinder Head → PLE Cylinder Head → PRA ECU →
With a Hasport EG H-series mount kit and Hasport driveshafts the H22A is effectively a bolt-in swap; only the wiring needs custom adaptation. The passenger-side axle reuses the H22A intermediate shaft with the Hasport shaft fitting straight into it; the driver side is a complete Hasport assembly. The Civic clutch slave cylinder is used instead of the Prelude one for clearance and bolts on with one extra hole drilled in the bracket; the Civic reverse light switch fits the H22A gearbox directly. The Civic reverse-flow fuel line from rail to filter needs fabrication, and an uprated in-tank fuel pump (Walbro GSS341 here) is recommended. A standard EG intake pipe and pod filter fits the H22A. Documented result: 14.2 s quarter mile at 101 mph with only intake and 2.5-inch exhaust; total swap cost $5,545 on-road (2004).
Chassis: the driver-side gearbox mount must be cut off below the suspension tower for the Hasport mount kit, and a clearance scallop cut into the body near the passenger headlight if the power steering pump is retained (alternatively a 1997-on Prelude pump and bracket clears without cutting). The shifter opening must be enlarged because the Prelude uses a cable shifter where the Civic uses shift rods. The complete exhaust must be replaced - Prelude headers are much longer than the Civic items. Wiring: the Civic engine harness is adapted to the H22A, including extending the alternator power wire, changing and extending injector wiring, a mandatory injector resistor box for the stock peak-and-hold injectors, and new circuits for the O2 sensor (Prelude connector, pins D14/A6/D22/A25 on an OBD1 Civic ECU), VTEC solenoid (A4), VTEC oil pressure switch (D6), knock sensor (D3), intake bypass solenoid (A25/A17) and EGR (A25/A11, A25/D22/D12 - only needed with a P13 ECU).

Important Caveats

  • • Do not use standard Prelude engine mounts with relocated Civic brackets - documented installs done that way repeatedly break mounts from the added stress.
  • • The heavier H22A reduces ground clearance at the sump and headers; on 14-inch wheels clearance is unacceptable and springs must be chosen for the extra weight.
  • • The swap must be engineered/certified for road use (this build was mod-plated after completion in Queensland).
  • • A B18C is an easier swap into an EG with more aftermarket support, and total cost often ends up similar despite the H22A's cheaper purchase price.
  • • EGR wiring is only functional with a P13 ECU; P28/P72 and similar ECUs ignore it.

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Community Verification

1
user verified this swap
By honda_b_blastn via OzHonda
Added 7 hours ago

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Sources & References

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