Here's the quiz:

1990 RS race car (stock motor etc) with the 130hp engine. We're swapping for the 93 b18 engine to gain the extra 10 horses.

I realize there is a difference in the wiring harness and ECU between the two G2's but could use some education on what I need to make this swap as pain-free as possible.

Again, this is a stock swap between years - no fuel management, VTEC heads, etc...

TIA

Greg

 

Next time PM me for my phone #

The 93 is OBD-1. You're going to need to replace:

- Distributor
- Injectors
- O2 sensor and extend the wire (mounts down on the downpipe now)
- ECU
- Various sensors on manifold may be different (no air boost valve on 93, for one)

Its easier just to swap all that chit onto the 90 motor you have rather than update to OBD-I.

Also, the only difference is head/cams/manifold/ecu trim. The bottom ends are identical, so do the top end swap and chip the ECU - chips are $20 on ebay if you havent done it already.

B18B heads are identical, but on separate lines in the GCR, so cant use those. IF you wanted, the B20Z cams (99+) stamped "P75" have a few more degrees of duration on the intake side if you wanted to be sly.

 

Do you realize that all the power from the '92-'93 B18 engines is found in the head? Revised cam profiles and a better intake manifold as well as some slight ECU tweaks are all that seperates them from the '90-'91 engines. Just something to think about...

To answer your question. All you need are some OBD-I injectors, harness and a distrbutor if your '93 motor didn't come with them. A T-belt and waterpump are always a good idea, as well as crank seals and a new clutch. Keep in mind you'll still need to use a '90-'91 clutch disk with your A1/S1 transmission. That should make it pretty painless.

 

Beat me to it...

 

thanks JDM and RJ

I have a complete built (read - decked, bored, balanced 93 engine) motor w/harness ready to drop in.

My Acura guy says we'll use the 90 harness and ECU and change the 90 sensors to the 93 motor and splice the others. Is this the way to go?

I don't have a 93 ECU or cabin harness for the progect. The 93 motor has all the sensors and engine harness...

If I am unclear on anything, pls ask..

 

Just use everything (well not everything but the important things pointed out before) from the 91 motor. ALot of things will be the same or have the same hookup, like temp sensors and map sensor and stuff. If you have an intake w/ a hole for the air boost valve - plug it. That was the only difference i had to make w/ the 93 LS head I put on my motor. Oh i think the IACV on the back of the manifold is different, use the 93 piece.