B20 Swap: Detailed How To Guide
Chiddie
New Wagonist
Hey all, I decided to write up a detailed B20 swap guide with a comprehensive parts list upon completion. I am doing this to help out anyone who might be doing this swap as I am a Honda swap newbie so it will include stuff that some "vets" may overlook as routine. Also, it will be a memoir of sorts so I can recall all the details. This swap is actually a D to B swap, an auto-to-manual conversion, OBD0 to OBD1 conversion, and DPFI to MPFI conversion in one happy package.
Step 1: Cut a hole in the box...(jk)
1. Prepping your old motor for Removal: Drain all the fluids and start tearing her out. When you do this, do yourself a favor and label every wire and hose as there are many that will plug into multiple sensors/ports. I removed the engine harness first by just following it from the main harness on the left to the right. Next, the intake manifold and respective vacuum lines. Then exhaust manifold, alternator, AC compressor, intake/air filter, battery/battery tray, radiator, plug wires/distributor, and PS pump (mine was already gone). Finally, I removed the front crossmember. This should leave the motor/transmission/axles and the respective mounts. (I put red "streamers" on all my ground wires as a lot of people forget to hook them all back up).
2. Crossmember: Cut the front mount bracket off, clean, and paint.
3. DPFI to MPFI Wiring: I am using OBD1 injectors so I am not running an injector resistor box. The best write-up I found is here. http://www.b20vtec.com/forums/technical-information/436716-dpfi-mpfi-conversion-diagrams.html . It isn't very tough, just a little time consuming.
4. Auto-to-Manual Prep: I started off by removing the dash, dropping the steering wheel, removing the metal bar above the steering wheel, and the ductwork behind it. This was actually a lot easier than it sounds. I then unbolted and removed the auto pedals. In the 88/89 models you will need to remove a bracket for a clutch cable from a manual wagon to install and drill a hole for the cable. Install the bracket and install the manual pedals from a Wagon. (I cannot locate a parts yard wagon so I made a bracket and installed hatchback pedals with modifications to the ductwork.) Next, remove your console and automatic shifter...pitch it. You will need to construct a cover plate to be bolted/epoxed to cover the gaping automatic shifter holes. Finally, bolt up your standard shifter.
5. Prepping your B20: Remove the intake manifold, alternator, PS pump, and exhaust manifold. I threw the manifolds away (after removing hoses/sensors) as there is about 0 resale on them. Clean the gasket surfaces of residue and cover with painters tape. Install your flywheel/cluch/pressure plate according to the manual and finally install the transmission. I am leaving the bolt-ons off to make the motor easier to install. Do any maintenance you want to do at this time (water pump, timing belt, thermostat, head gasket, main seals, cam seals, plugs, etc.). This is totally up to you what you decide to do. If you are running OBD0 you can do your dizzy now. I am going OBD1 so I am sticking with the stock OBD2 B20 dizzy.
This is where I'm at thus far and will update after I make some serious headway on my swap this weekend.
Step 1: Cut a hole in the box...(jk)
1. Prepping your old motor for Removal: Drain all the fluids and start tearing her out. When you do this, do yourself a favor and label every wire and hose as there are many that will plug into multiple sensors/ports. I removed the engine harness first by just following it from the main harness on the left to the right. Next, the intake manifold and respective vacuum lines. Then exhaust manifold, alternator, AC compressor, intake/air filter, battery/battery tray, radiator, plug wires/distributor, and PS pump (mine was already gone). Finally, I removed the front crossmember. This should leave the motor/transmission/axles and the respective mounts. (I put red "streamers" on all my ground wires as a lot of people forget to hook them all back up).
2. Crossmember: Cut the front mount bracket off, clean, and paint.
3. DPFI to MPFI Wiring: I am using OBD1 injectors so I am not running an injector resistor box. The best write-up I found is here. http://www.b20vtec.com/forums/technical-information/436716-dpfi-mpfi-conversion-diagrams.html . It isn't very tough, just a little time consuming.
4. Auto-to-Manual Prep: I started off by removing the dash, dropping the steering wheel, removing the metal bar above the steering wheel, and the ductwork behind it. This was actually a lot easier than it sounds. I then unbolted and removed the auto pedals. In the 88/89 models you will need to remove a bracket for a clutch cable from a manual wagon to install and drill a hole for the cable. Install the bracket and install the manual pedals from a Wagon. (I cannot locate a parts yard wagon so I made a bracket and installed hatchback pedals with modifications to the ductwork.) Next, remove your console and automatic shifter...pitch it. You will need to construct a cover plate to be bolted/epoxed to cover the gaping automatic shifter holes. Finally, bolt up your standard shifter.
5. Prepping your B20: Remove the intake manifold, alternator, PS pump, and exhaust manifold. I threw the manifolds away (after removing hoses/sensors) as there is about 0 resale on them. Clean the gasket surfaces of residue and cover with painters tape. Install your flywheel/cluch/pressure plate according to the manual and finally install the transmission. I am leaving the bolt-ons off to make the motor easier to install. Do any maintenance you want to do at this time (water pump, timing belt, thermostat, head gasket, main seals, cam seals, plugs, etc.). This is totally up to you what you decide to do. If you are running OBD0 you can do your dizzy now. I am going OBD1 so I am sticking with the stock OBD2 B20 dizzy.
This is where I'm at thus far and will update after I make some serious headway on my swap this weekend.
Comments
Removal of the D15: Go ahead and get a big cheater bar for the axle nuts. We bought a 6' piece of 1.5" steel tubing and used it over a 24" breaker bar. Also, buy the real axle socket. I snapped a regular 32mm socket like it was plastic. Use a fork for the ball joints; they pop really easy actually. We did not remove my AC lines as I didn't want to get it recharged. The lines were easy to go around.
Installing the B20: Put the DS mount on the motor and leave the rest off. Bolt in the rear motor mount before dropping it in or you will wish you had. Handtight the DS mount to chassis, install T-Bracket handtight, then install tranny mount handtight. Snug 'em all up.
This is where I am at for now. I'll update with pictures when I can access a computer. I'll be wrenching on her all day tomorrow and will update as well.
My "garage"...lots o' square footage
D15 Removal
B20 dropped in
Before putting the motor in: DON'T FORGET to beat the living daylights out of your inner fender directly below the square cut-out on the frame rail. I forgot and have plenty of busted knuckles swinging a hammer in a small space. This is for alternator clearance.
Intake Manifold/Throttle Body: I started by installing the intake manifold. I ran a coolant hose from the coolant tube on the back of the motor to the IACV, then from the IACV to the FITV? (bottom of throttle body, can't recall the exact name) and then from the FITV to the upper radiator hose fitting. Next, I ran the heater coolant lines. Finally, the vacuum line from the manifold to the valve cover and from top of the manifold to the brake booster.
Shift Linkage: The "bitch" pin lived up to its name. I beat the heck out of it with a hammer but it finally went in after about a half hour. I found it is easiest to squeeze and twist with needle nose pliers while beating it in. (I hope I never have to remove it and I question the design anyways. I bolted the shifter to the tranny and drilled holes where it mounts behind where the auto shifter was (I had done this already but my location was wrong). This was all straight forward.
Things such as radiator, alternator, AC compressor, etc. were all just the reverse of removal less I used an Innovative AC bracket.
Engine Harness: I had to extend the water temp switch wires (was on back of D15 and it is on the thermostat of B20), the TPS, and the oil pressure sensor. Make sure to connect the thermostat ground when installing the harness.
Crossmember: Align the crossmember up with the bolt holes for header clearance measurements. More than likely you will need to cut off the "lip" to clear the header.
Radiator: The B20 hose openings are significantly larger than the stock D15 were. I ran a stock CRV lower hose using a hose clamp to tighten down to the radiator. On the upper I had a crazy "S" curve that I couldn't find a hose to fit so I went with a universal flexible hose. This worked out better than I thought.
JDM B20 Motor
YS1 Transmission
Clutch Cover Plate
DA Clutch and Flywheel
DA Flywheel Bolts
DA Clutch Bolts
90-93 Acura Integra (DA) Shift Linkage (cut to fit)
Energy Suspension Shift Linkage Bushings (mine were damaged)
New OEM Linkage Pin and Clip
B-Swap Motor Mounts
DA Clutch Cable (I've heard stock Wagon will fit)
DA Throttle Cable
DA Axles and Half Shaft
New OEM Axle C-Clips
DA Complete Intake Manifold/Throttle Body, Fuel Rail/Injectors (I am using OBD1 here)
Stock Wagon Pedal Assembly (I did auto to manual swap; HB will work if necessary)
DA Starter
DA OBD1 ECU
DA or Aftermarket Header (my aftermarket has better clearance)
DA T-Bracket
Innovative AC Bracket (if it is 80 degrees in January like here)
Monotech OBD0 to OBD1 Jumper (the harness is of great quality and their service is great)
Custom Radiator Hoses and Clamps
DA Fuel Line
Replacement Fuel Filter (mine was old)
40 ft of wiring
Fluids/Maint (Coolant, Air Filter, Oil, Oil Filter, MTF)
...I pieced all of this together which was not wise or cost effective. Do yourself a favor and buy a B18 swap and then sell the motor.
Dipstick: This thing was literally 4" too high. I cut the tube off below the mounting bracket. Then cut the dipstick in half. I overlapped the 2 dipstick pieces the same lenth as the tube I cut off and used JB weld on it.
Hood Clearance: You may have no issues but my mounts are old school so I had to notch the hood support beam to clear the valve cover. I removed about a 3" section.
No start: Issue was that I had unplugged my ignition switch from the fuse box when I removed the dash.
No fuel: It would run on starting fluid sprayed into the throttle body so I had spark but no fuel. I had no power to the yellow/black wires at the injectors. I started by testing the main relay and it was good and checking the fuel pump which was also good. I went over my wiring and found the issue at the dizzy. The wires that run from the dizzy to the plug are different colors than those that are on the stock CRV plug I wired into my harness. I do not know why but instead of matching color to color from the OBD0 Civic Harness to the CRV plug (that plugs into dizzy plug), you need to match color for color from the OBD0 Harness to the dizzy plug. This means you may have a "purple" to "pink" wire on the harness side but in actuality it goes "purple" (OBD0 Harness) to "pink" (CRV wiring to plug that connects to dizzy plug) to "purple" (B20 Dizzy) and the pink would be "pink" to "purple" to "pink". This is a generic description as these wires don't exist but every wire was backward when just wiring the stock CRV plug that was cut off of the CRV harness to my Civic engine harness. I drew a picture as this is difficult to comprehend from reading.
It starts and runs find now but I have a high idle issue which is probably a vacuum leak at my rigged up evap.