B18c1 in a 88-91 Civic Question
 

I am planning a motor swap for my 91 Civic hatchback this December. I was planning to buy a b16a1 complete swap and a b18c block separately, then switch the b16 out in favor of the b18. Will I run into problems using the s1, j1, or y1 cable tranny? I have heard that I will run into computer problems using this set up. Does it matter if I get a OBD 1 or OBD2 block? Which computer works best; Pr3, P72, or the Si ecu with a VTEC controller? Does anybody have experience with this set up? How reliable is it? Any help is greatly appreciated as well as opinions on how to build this up correctly. Thanks in advance.

The OBD I and OBD II C1 blocks are the same. The only differance that I have noticed is the oil pump. It has an extra sensor. I believe it is the crankangle sensor. The OBD I pumps don't have a mount for the sensor. The timing belt drive gear is differant on the OBD II motors also. It a "gear" on it so the prox sensor (crank angle sensor) has something to read from. So the timing belt gears have to stay series specific. You mentioned the Si ECM... Do you have an Si model ?? I beleive the other models are throttle body injection and only wired for two injectors. I did a ZC swap into a 89 DX hatch and I had to use harness adapters to convert it to multiport injection. After you do that, the PR3 will plug rgt in. As you know the P72 is the OBD I GSR ECM. You will be using a B16 head on the B18C1 block. (i'm assuming that is what you are talking about doing) The P72's map has a differant VTEC crossover point than the PR3's. It's fuel and ignition maps change at 5800 RPM for the secondaries opening. Does stuff you won't want it too. PR3 sounds like the way to go.