i know many of you will frown on this swap, but, i just blew my motor from too much boost and problems with my hondata. finding obd2 b16 longblocks are hard. the b18b1 is so much easier to find. besides, its only temp until i slap some new rods, valves, and pistons on the b16a2.

anyways, ive found plenty of obd1 and obd2 b18b1 longblocks. i assume putting the obd2 b18b1 is a direct swap using the existing motor mounts on my si. i would make this post easier by going obd2, but, my friend has an obd1 b18b1 block in his shed. what would be needed to get this obd1 longblock running in an obd2 99 civic si chassis.

i know i will need the intake mani from the b18b1, but, will the existing b16 exhaust mani fit. i ask because i know the b18 exhaust manis are taller than the b16s. im concerned with the b16s header clearance on the b18.

TIA

 

Yeah you may have clearance issues with that exhuast manifold...
Yes you will need to take all the mounts (including the bracket that bolts under the timing cover) from the Si and move them over.
If you swap your B16 injectors over onto the B18 manifold there will be NO wiring mods to make! Just get an OBD2b to OBD1 adapter harness and a 94-95 P75 ecu. If it does not have the manifold or throttle body you can use at least the throttle body from the B16 (also the throttle cable bracket) and just get a bare LS intake mani.

Top end will be weak compared to the Si, but an LS with Si tranny will come off the line hard with that extra torque and short gearing!

 

so the stock wiring harness is fine then. if im swapping obd1 ls longblock with the 94-95 p75 ecu, i would assume i would need obd1 injector clips. if i was going with the obd2 ls longblock, i thought that is the only case i would retain the obd2 clips?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spidermancivic &raquo;</TD></TR><TR><TD CLASS="quote">so the stock wiring harness is fine then. if im swapping obd1 ls longblock with the 94-95 p75 ecu, i would assume i would need obd1 injector clips. if i was going with the obd2 ls longblock, i thought that is the only case i would retain the obd2 clips?</TD></TR></TABLE>

That's why I said to swap your B16 injectors onto the OBD1 longblock, so you would not have to change plugs. A lot easier to swap injectors then plugs. The injectors are the same except for plug style, either one works with any ECU, you don't have to use OBD1 injectors just because you have an OBD1 ecu.

For instance, if you were going to convert your B16 to OBD1 for Hondata or something, you wouldn't have to unplug or change anything under the hood. Just plug in the conversion harness and ecu and that's it, providing the ecu has the correct program on it.

 

i see.

so there is no difference in the sensors. si harness will plug right up?

 

Oh I forget one thing but I don't think it matters as long as you use the Si intake pipe and IAT. The B18B has the IAT bolted onto the manifold but you can use the one in the Si intake pipe and just ignore that one. You will also ignore the crank sensor plug, there's nothing to hook it into on an OBD1 block. Everything else should be cool!
One more thing I just thought of...use your Si fuel rail, it has the mount for the purge control solenoid too I'm not sure where it's at on the OBD1 B18B...