CRX Engine Swap Guide

CRX Engine Swap Guide

I am the proud owner of a 1991 Honda CRX Si-R. It has a Ractive cat back exhaust system and a Ractive cold air intake kit installed. I killed the original motor, so I dropped in a 1.6L DOHC VTEC. I was going to replace the exhaust manifold with a header, but I plan on installing a turbo kit and turbos require a custom manifold so purchasing a header would be a waste of money. I have a Zex nitrous kit installed with a bottle warmer and a purge kit. The car has had all the rust cut out, so the body is rust free. I also removed all AC related equipment because it is a waste of space and extra weight. I chipped the ECU to remove the rev limiter and governor, installed a short throw shifter, and installed rear disk breaks in one day. A Y1 LSD (Limited Slip Differential) transmission and a Z10 Radius Arm Traction System were installed for better traction and a Walboro 255lph fuel pump was added. I have a Garrett T3 turbo, custom turbo manifold, intercooler, blow-off valve and turbo chip just waiting to be installed.

2002 race season: B16A engine, muffler, cold air intake, removed AC equipment, body work to clean up the rust
2003 race season: Zex nitrous kit, Zex bottle warmer, Zex purge kit, ECU NOS chip, LSD transmission, 255lph fuel pump, short throw shifter, rear disk breaks, 2000 Civic Si rims, Stage II racing clutch

2002 Best Run: 15.03 @ 93.76
2003 Best Run: 13.53 @ 105.44 (75hp shot of nitrous)

There is a lot of confusion out there as to what you need to do a swap. I've visited hundreds of web sites and no two sites provided the exact information. Each one was different. The purpose of this page to let everyone know what I did to make my swap work just fine. All instructions here are for a b16a conversion into a 1991 Honda CRX DX. The wiring harness you need will be different if you have a Si or HF.

I dropped a 1st Generation b16a Si-R enigne into my 1991 Honda CRX DX. I received shift linkage, ECU, motor mounts, front suspension and engine. I have no clue as to the origin of the shift linkage, but I'm about 98% sure it's from a 1990 - 1993 Acura Integra. I believe the front suspension is from a 1991 Acura Integra. We bought new rotors for that year and they were an exact fit so that's my guess. Don't quote me on that. Anywho, dropping this engine into a DX is a little bit harder than dropping it into a HF or Si. The HF and Si have Multi-port fuel injection whereas the DX has Dual Point. Since the DX is only Dual Point (2 injectors), you have to run wire for 4 injectors because the b16a is Multi-port. I plan on providing links or downloads of all the helpful diagrams and articles that helped me rewire the DX harness for the Si-R engine. Rewiring is hard and tricky but it will save you about $250 (the cost of a conversion harness). Another problem you will run into is shift linkage. The linkage we received with our engine had to be cut by about 2 inches. I am not sure what kind of car it came from but my guess is an 1990 - 1993 Acura Integra. You also can puchase exact fitting shift linkage for about $150. Also, you will need new motor mounts. They run about $450. A great place to shop and a great place for information is Hasport. You can order your linkage, motor mounts and harness from them.

I've visited many sites that say you will need to put on a new front suspension to accommodate the Integra axels. I have no idea if this is true or not. We were shipped the suspension with the engine so we used it and it works just fine. We didn't try it with the old suspension, so I cannot confirm the rumor. All I know is that the Integra suspension works great.

Since this motor is straight from Japan and was never introduced in America, finding the correct parts is a pain in the ass. Here is my parts list:

Engine = 1988 - 1991 Honda Civic Si-R & 1990 - 1993 Acura Integra XSi (b16a 1st Gen)

Wiring Harness = Hasport $249 or you can rewire your stock DX harness, which is what we did

Shift Linkage = Hasport $150 or you can cut and weld Integra linkage, which is what we did

Motor Mounts = Hasport $449

Water Pump = 1994 Honda Del Sol VTEC (22 teeth)

Timing Belt = 1994 Honda Del Sol VTEC

Clutch = 1990 - 1991 Acura Integra

Upper Radiator Hose = 1992 Acura Integra GSR (trim to fit)

Lower Radiator Hose = 1990 Acura Integra (trim to fit)

Throttle Cable = 1990 - 1993 Acura Integra

Distributor Cap = 1990 - 1993 Acura Intergra

Clutch Cable = Stock

Rear Disk Brakes = 1991 Honda CRX Si

Axles = 1990 - 1993 Acura Integra

Front Rotors = 1990 - 1993 Acura Integra

Spark Plugs = 1994 Honda Del Sol VTEC

Spark Plug Wires = 1994 Honda Del Sol VTEC

Chassis = A dent will have to be made for alternator pulley clearance.

Exhaust = The stock exhaust manifold on the Si-R engine is a perfect fit with the CRX mid-section and CRX catalytic converter. But you will have to take your catalytic converter to a local shop and have them re-weld the flange that connects to the exhaust manifold because the bolt holes do not line up. You can also buy a Bosal high-flow catalytic converter with the flanges that are free moving and not welded.

I would like to thank everyone who helped with the install. Dad, Jamie, and my bro Tom. Especially my Dad. He did just about everything. It's great to have a mechanic as a Father. Saves money.