It was a cardinal sin by any Pope's definition when Honda decided to kill the CRX. The two-seater only survived a couple of generations, but in that time it romped through SCCA road racing classes, added fuel to the Honda tuning and tweaking fire, launched performance companies and race teams (King Motorsports and Mugen dominated with a second-gen model) and made us all cry when it morphed into the del Sol to please insurance companies.
All of that success created a legend that is passed on to Honda lovers as they become of driving age and start dreaming about building their ultimate Honda. Veterans know a CRX is so light and nimble right out of the box that getting one to go fast on the track is a matter of simple math. Getting the CRX to go fast on the dragstrip is another story. The original engines were pretty good in their day, but now that we're in the middle of an all-out factory horsepower war, those D-series lumps just won't do. Enter Hasport--innovators in the Honda engine swap--with a solution.
Regular readers know we've covered Hasport K-series swaps for the '01-and-up Civic and the '94-to-'01 Integra. Hasport also makes a kit for the EK/'96-to-'00 Civics. Here's one of the next potentially superpopular swaps: The K-series-powered '88-to-'91 Civic/CRX.
This swap completes the Civic series and is about as far back as the K can go on a Civic. The '84-to-'87 Civic/CRX engine bay is just too small for a K without major mods and/or fabrication.
You'll need a K20A (or A3) long block with harness, transmission with shift cables and ECU. Forget the axles. They're custom, but available from Hasport and others. You'll be cutting a hole in the hood to clear the idler pulley unless you plan to purchase Hasport's alternator relocation kit. The K20 engines are tall, but an SiR-style hood will close. If you use a K24 block, you'll definitely need to cut into the hood.
The transmission poses a problem since your EF chassis uses a cable-operated clutch. The K is hydraulic, but Hasport's mount kit ships with a cable-to-hydraulic conversion unit. The next stumbling block is the shifter. No solid shift rods will make a K tranny shift, especially since the tranny is on the opposite side! The cables from the K transmission connected to a shifter box from any RSX works great. Wiring is the biggest challenge of this swap. If you're solid with your color codes, you can do it yourself. Hasport offers a complete conversion harness for $350 that lets you plug in the K-engine harness to the majority of the Civic/CRX engine and cabin plugs. Less than 10 wires need to be physically wired with the harness.
The speedo on the Civic/CRX is cable-driven, while the K is electrical. There's no fix for this yet, unless you can source an SiR gauge cluster or fit one from an EG. If you're hunting EGs for speedos, grab a radiator while you're at it, unless you plan to run an aftermarket unit. The last thing to know is that a CRX HF or a four-speed Civic has smaller and incompatible front suspension knuckles. Replace them with knuckles from any five-speed fourth-generation car or '90-to-'93 Integra. Same goes for the front crossmember. A Full Race, Z-10 or similar tube-style crossmember needs to be used for clearance.
With a killer K CRX up and running, you may want to look again at the suspension. A K-series with axles and transmission weighs about 350 pounds. The old D motor was 200 and change. The front shocks will likely have lost travel and easily bottom out.
Cracking this K Nut what you need to know about this swap:
•Unless you skip the idler pulley, you'll becutting the hood
•Make sure to get the transmission, shifter cables and ECU with your K engine
•You'll need custom axles
•It won't meet CARB emissions requirementswithout serious investment
•The stock speedometer won't work, but a JDM SiR cluster will
•A custom header and some exhaust work are required
•If you're not skipping the idler pulley and you're not using a Civic Si engine, get one from an EP3 K20A3
•Get a radiator from an EG or EK
•The wiring on this one is a bitch. Get the Hasport kit