The swap guide should tell you all you need when using the PR3 and Skunk 2 intake manifold. But I’ll post it here so there’s no confusion…
Engine: 1994-1995 USDM B18C1
Displacement: 1797cc
Compression Ratio: 10.0:1
Hp/Torque: 170hp@7600rpm/128lb-ft@6200
Transmission: Y80 (hydraulic)
This is an OBD-1 engine from 94-95 Integra GSRs. This motor as you can see puts out slightly more hp than the XSi B16a, but the big difference here is the torque. This motor has 16ft-lbs. more torque. Which is pretty significant. This is the only Honda motor that has the “upside down” intake manifold. It also has secondary butterflies in the dual intake manifold runners. This is the reason for the early VTEC crossover point with this motor (4400rpm). If you are worried that the B16A is not going to have enough torque for your liking, this motor is a good solution. However, with the higher performance, you will pay a higher price. Price on this motor will vary as well. Sometimes you can find a deal for about $3000, other times you may pay up to $4000 for one of these motors. Mileage on this motor will vary, because it is a US Spec motor and we don’t have to pull our motors at 40,000 miles. Many people prefer to go with the 90-91 JDM B16A not only because it is non-OBD (not as many issues when putting the motor in), but because of the cheaper price. These are the only items of concern with this swap:
• Wiring Harness-You will need to use your existing B18A1 cream plug wiring harness. It will plug into everything on the motor except for the distributor and injectors. You’ll have to add the 3 wires for VTEC, knock sensor wire, and the second oxygen sensor. Also, the temperature switch on this motor is located on the thermostat housing unlike your B18A1 which is located on the back side of the block, so you will have to cut and extend the two wire plug to reach the thermostat housing. But this is fairly easy. The gray plug harness that comes with the OBD-1 B18C1 cannot be used, but can easily be sold for $100-$125 as they are in high demand.
• Motor Mounts-Use your existing B18A1 mounts. They slightly different than the B18C1 mounts.
• Distributor-You can use your B18A distributor but the leg towards the front of the car has to be cut off to allow clearance for the VTEC purge assembly. You will only have two bolts holding your distributor, but that is adequate. You can do this or your other choice is to buy a non-OBD VTEC distributor (PR3). You can find them on the net for as little as $100, but most are priced at about $150. The OBD-1 Distributor that came with the motor cannot be used but can be sold for $150-$200.
• Intake Manifold-This is the biggest difference when using this motor. This is the only Honda motor that has the “upside down” intake manifold. It also has secondary butterflies in the dual intake manifold runners. What I recommend doing is getting rid of this manifold and TB entirely and getting the Skunk2 Intake Manifold (pre-modified to fit the P72 Head). ). Because you cannot use the P72 ECU that controls the secondaries in the intake manifold (that only the B18C1 has), this is the best solution. Then use an ITR TB or your LS TB (maybe bored out by RC Engineering). You can use an ITR Intake manifold but it needs to be modified to fit (by a machine shop),
• Injectors-You will need to use your existing non-OBD B18A1 injectors. The OBD-1 injectors have a different plug on them made for the gray OBD-1 harness. Other than that, the injectors are identical.
• ECU-This motor will come with an OBD-1 VTEC ECU (P72). You cannot use this ECU with your harness that is inside your vehicle (non-OBD). So sell it and buy a non-OBD VTEC ECU (PR3, PWO). Either one of those ECU’s will run the OBD-1 B18C1 (with Skunk2 Intake Manifold) perfectly with your B18A1 harness.
• Transmission- This engine also comes equipped with a hydraulic transmission, which either needs to be swapped out for a short geared cable transmission (J1, S1) or I believe Place Racing makes a hydraulic to cable converter that you can use. But then you are talking about more money. Again you can buy a YS1 short geared transmission, but you will need a clutch assembly from a 92-93 Integra or if the B18C1 motor came with a clutch and flywheel, you can use those.
• Clutch-Depending on what transmission you go with (90-91 or 92-up cable transmissions) will determine what clutch you should get. If you get a 91 or older cable transmission you will need a 90-91 Integra clutch assembly. If you go with the 92 up YS1 Cable transmission, you will need a 92 up Integra clutch assembly. Use the matching flywheel with the same clutch.
Below are things that I recommend doing while your motor is out and before you drop your B18C1 in:
• Replace the water pump & thermostat
• Replace the timing belt and timing belt tensioner
• Replace Cap, Rotor, and Spark plugs
• Adjust valves
• Replace valve cover gasket and spark plug seals
• Replace fuel filter
• Replace PCV valve
Got messed up. Might want to revise what your saying about non-obd harnesses pluging into obd-1 distributors. Granted the wires may be the same, but I put a non-obd engine in my obd-1 '92 teg and the distributor does not plug in. Nor does a obd-2 plug into a obd-1 harness. used my LS’s original obd-1 distributor and cut a leg off.
