Honda K20A / K20Z

Honda's naturally aspirated 2.0 i-VTEC — the K20A and K20Z — in the Civic Type R, Integra Type R and Acura RSX.

⚑ It is not the K20C turbo that replaced it and has its own page here, and it is not the K24. Three K-series engines, three pages, and the letter is the only place the difference is written.

Its i-VTEC combines variable lift with variable cam timing, and the failure that matters presents as the engine simply not changing character above about 5,800 rpm. Low oil level, a clogged solenoid screen or a failed pressure switch all produce it, and all three are cheaper than what people assume. Check the oil and the screen first.

It is chain-driven, which removes the belt anxiety that defines the older Honda families — but the chain tensioner rattles on a cold start at high mileage and is worth acting on.

These engines are swapped constantly, and a stamped code on a rebuilt one may not describe what is inside it. Confirm the build before trusting a compression ratio.