Y7 into the 91 hatch

[Hendo]

Alright, so my 91 hatch runs strong but loves to eat the oil, as well as seemingly spray it from god knows where. I've pulled the trigger on a GSR swap for the 92, so I'm going to have a Y7 with 120k miles on it that runs fantastic and eats ZERO oil as an "extra" motor. It wasn't converted to obd2 or anything, it looks like all the B7 stuff was bolted onto the engine.

Questions: I want to use the block and head, how little of the power-robbing restrictive junk needs to go along with it? I'd like to cannibalize as much of the A6 as I can (the exhaust will fit, I know), it's so much more of a little monster than this dog. Part of this swap is keeping the sweet A6 tranny as the Y7 one has a noisy throwout bearing and has some grindy synchros to boot (its a 91, I know the splines match) which is partly why I just decided to swap that one. Plus, I've got reman axles I bought a few years ago just sitting in my garage for the 91.

Can I use the A6 intake? How about the ECU?

I do have an obd0 to 1 conversion wiring harness I got for the Z6 swap, and the distributor is the big question for me. Can/should I just use this conversion harness? Can I use PART of the harness and keep the A6 ECU? The distributor has it's own wiring piece, ideally I'd like to bolt everything onto the Y7 block/head from the A6 and just use the clip for the dizzy and call it a day. But the question is: does that work? XD

 

[jlicrx]

use the A6 intake manifold on the Y7

A6 transmission, flywheel, clutch, etc. will all work

use the engine wiring harness from the A6 - only one minor change (see below)

the PM6 ECU will work as long as you use the A6 distributor, which bolts right onto the Y7 head - you cannot use the OBD1 distributor as it isn't compatible with the OBD0 ECU

you need to swap the A6 engine mount on the driver's side end of the block onto the Y7 block - you may have to modify the timing belt cover slightly as the mounts are a little different configuration

you will need to make a minor wiring change to the A6 engine harness - the Y7 has the cooling fan switch on the thermostat housing - the A6 has the cooling fan switch on the back of the block next to the oil filter - you need to swap a 2-wire connector onto the A6 harness so that you can plug into the switch on the thermostat housing

don't worry about the crankshaft speed fluctuation sensor which is behind the crank pulley on the Y7 - the PM6 ECU won't be looking for it - you can remove the sensor or just leave it not connected

 

[jlicrx]

in order to run the engine as OBD1, you would need an OBD1 P06 non-VTEC ECU from 92-95 Civic DX - you would also need to use the OBD1 non-VTEC distributor from 92-95 Civic (can't use Z6 or Z1 distributor as they won't bolt onto the head) - you would need to use the OBD0 to OBD1 ECU jumper

 

[R3dline]

y7? , kind of a crappy motor,

 

[Hendo]

Well the whole running shebang is in the 92 right now, ECU, dizzy etc. It's completely complete. Are you saying with the dizzy jumper all I would have to do is use the jumper, swap ECUs and intakes, and change one motor mount?

 

[Hendo]

y7? , kind of a crappy motor,

If I go 80mph on the freeway between here and Detroit (160 miles), it'll eat two quarts. That's each way. THAT'S a crappy motor lol

 

[Hendo]

in order to run the engine as OBD1, you would need an OBD1 P06 non-VTEC ECU from 92-95 Civic DX - you would also need to use the OBD1 non-VTEC distributor from 92-95 Civic (can't use Z6 or Z1 distributor as they won't bolt onto the head) - you would need to use the OBD0 to OBD1 ECU jumper

And thanks for the info, btw. Exactly what I was looking for.