Honda Civic SiR

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B16A Engine Installation

This page contains the more information about and photos of the B16A engine swap into my Honda Civic SiR. The donor engine was obtained through Dodsons Autospares, a local importer/wrecker of used parts from Japan. The B16A engine is from a 1994 EG6 Honda Civic SiR (determined from the timestamp on the head).

Overall, the B16A engine swap went relatively smoothly. However, there were a few snags and this page contains some of those snags and photos of the process that converted my Honda Civic SiR into a Honda Civic hybrid.

Installation Steps - Problems - Results - Things to Retain

Installation Steps

Below are details and photos taken during the various stages of the B16A engine swap into the Honda Civic SiR. You can click on each of the photos to get a full size version.

  1. The new engine with the rocker cover off to inspect the cams and rocker arms for any signs of wear. Everything looked pretty good with only a few very small shiny patches on a couple of rocker arms and high lift cam lobes. We replaced the timing belt since the engine had been sitting for a while, and inspected the water pump for signs of wear. The water pump looked and felt fine, so we didn't replace it.

    Second generation B16A with rocker cover off

  2. The engine with the intake manifold removed since we were going to replace the intake manifold gasket with a Hondata Heatshield gasket.

    Second generation B16A with intake manifold removed

  3. The engine with the stock Honda exhaust manifold removed since we were going to replace it with some Custom 4-2-1 Headers.

    Second generation B16A with exhaust manifold removed

  4. The engine with the intake manifold gasket removed all ready for the new Hondata Heatshield gasket.

    Second generation B16A with intake manifold and gasket removed

  5. The second generation intake manifold cleaned up ready for installation. Note the differences between a first generation one and a second generation one: extruded aluminium fuel rail vs cast alumimium, 3 moulded raised bars on top of the plenum vs a PGMFI label. The first generation fuel injectors have to be retained since they are a different plug fitting and have a different impedence.

    Second generation B16A intake manifold

  6. The Hondata Heatshield gasket in place on the engine. It is about 5mm thick and made of a material that does not conduct heat. It prevents heat soak from the head to the intake manifold to keep the intake charge as cool (and hence dense) as possible. This means you can squeeze every last pony out of the engine and it is relatively cheap to do.

    Hondata heatshield on second generation B16A

  7. The throttle body with the cold idle valve location blanked off with a piece of aluminium and sealed using some liquid gasket sealant. Note the difference between the second generation throttle body and the first generation. The first generation engine has the cold idle valve attached to the intake manifold whereas the second generation engine has it attached directly to the bottom of the throttle body. Also, the second generation throttle body is 60mm at the butterfly compared to 58mm for the first generation.

    Second generation B16A throttle body with cold idle valve blanked off

  8. The hot water that used to flow through the throttle body to prevent icing on cold mornings has been re-routed so that it completely bypasses both the throttle body and idle control valve. The hot water used to flow from the main return line through the IACV (idle air control valve) to the cold idle valve, through the throttle body and then back to the head. Now the hot water flows directly from the main return line directly back to the head. This should also help to keep the intake as cool as possible. Since the climate in New Zealand is relatively mild, there shouldn't be any problem doing this. And now that all of the other initial idle problems have been sorted out the car idles just like it used to.

    Second generation B16A hot water bypass

  9. Not a very good shot of the LSD. In LSD equipped gearboxes you can see directly through where the drive shafts get connected.

    Second generation B16A LSD gearbox

  10. Fabricating the new 4-2-1 headers on the engine. We sent the VTEC cam timings to Edgell Automotive to get the optimum dimensions for the exhaust manifold. The numbers returned were very interesting and very LARGE. The primaries are nearly 2" and they feed into some large secondaries and then onto a 2.5" full mandrel bend exhaust.

    Start of the fabricated 4-2-1 headers for the B16A

  11. The finished headers after receiving a ceramic coating. The two bungs for the oxygen sensors are located at the end of the collectors for the primaries.

    Fabricated 4-2-1 headers for the B16A Fabricated 4-2-1 headers for the B16A Fabricated 4-2-1 headers for the B16A

  12. The car with the old engine removed. That's quite a big hole in there. At this stage I really started to wonder why I was doing this. Too late to turn back though...

    B16A removed from EF9 chassis

  13. The old engine with the rocker cover removed. Suprisingly, not too much wear on the cams or rocker arms. The intake manifold was caked with oil and crap, but then I guess you get that with an engine that is over 10 years old. After cracking apart the gearbox, one side of the clutch plate had completely worn down to the rivets. The pressure plate was knackered because of this. There was also evidense of hot spots on the flywheel. Just as well the new engine came with a clutch and pressure plate that still has plenty of miles on them. Surprisingly I didn't really notice any slippage problems with the clutch even in its shocking state.

    Rocker cover off the first generation B16A

  14. The new engine in where the old one used to be. What a mission getting the new engine in! We had to notch a bit out of the front cross member because the new exhaust manifold managed to clobber the front cross member even after being fabricated on the engine and having it built as close as physically possible to the oil pan. Thank goodness for plasma torches, a guilotine that cuts through 2.5mm plate with ease, a pressbrake to bend it to fit, a few whacks with a big ball pein hammer and some MIG welding...
    We also had some problems with the CV (constant velocity) joints. The left hand side fell out and took ages to get back in. What's with those really annoying square bits on the bottom of the bearings? It makes it almost a three person job to put a CV joint back in.

    Second generation B16A in EF9 Honda Civic chassis

  15. The mass of wires and vaccuum hoses still to be connected up. There was only one electrial connector that needed to be altered (except of course for the re-use of the first generation B16A distributor). The fan switch for the second generation B16A is located next to the thermostat as opposed to being in the block. This required extending some wires and using the slightly smashed second generation temperature sensor. Honda New Zealand wanted an arm and a leg (nearly 1/4 of the price for what I paid for the engine) for a new one. Why can't people be a bit more careful when ripping out engines from wrecked cars? Scheesh.
    We also had to swap the throttle pulley for the first generation one so we could get full throttle properly.

    EF9 Honda Civic engine bay with all the wires still to be connected

  16. A shot of the new headers in the car. Not much room to move in there. In fact I ended up removing the back cover for air conditioning fan because the headers rested against them. Now I have about 3-4mm clearance. Tight!

    Minimal clearance for the new B16A 4-2-1 headers

  17. The engine all back together and actually running. Surprisingly it fired up straight away once the fuel rail had been primed with fuel. Unbelieveable! Just some initial problems with the idle that turned out to be because the second generation IACV has a bigger hole where bypassed air escapes. And the oxygen sensors were put in the wrong way round.

    The new engine all connected up

  18. The 2.5" mandrel bend exhaust. This was made on the car by cutting and welding lots of mandrel bends together. Note that the exhaust does not go over the rear suspension but rather around the fuel tank. There just wasn't enough room around the suspension for the 2.5" bends. Also no catalytic converter or temp sensor (because these were removed shortly after I got the car). I used the largest straight through resonator and muffler that I could find. No schwanky stainless steel muffler though because they cost about 5 times as much as a normal one.

    The complete 2.5" mandrel bend exhaust

Problems

Initially I had some problems with idle after the swap and some pretty bad hesitation problems when driving as well. I sent it to a local shop to have a look and they originally thought it was because there wasn't enough back pressure with the huge exhaust. They put in a back pressure restrictor, but that didn't help. Research on the Honda Hybrid Tech Forum made me realise that I might have put the Oxygen Sensors in the wrong way. I swapped them around and, voila, problem solved.

Results

The car felt a lot better with the new engine than what it did. It pulled much better with the VTEC cams activated but there was a mammoth torque hole just after VTEC kicked in as shown in the original B16A Dyno Run. This was because of the backpressure restrictor, which was eventually removed. Other than that it went pretty well. It's definitely louder than before when VTEC is engaged. It's a totally different car when the big cams are being used.

Things To Retain

Below is a list of all the things you need to retain from the first generation B16A (or things that need to be modified to work with the second generation B16A).

Tranmission
The EF9 uses a cable clutch whereas second generation (and higher) B16A engines all use a cable clutch so you have to keep the original gearbox. See the Honda Gearbox Ratios for more information on this and other gearboxes that might be suitable swaps.
Distributor
The second generation B16A normally runs with an ODBII ECU. The distributor used with this ECU has more teeth in it, and I believe the plug is different as well so you have to use the distributor off the first generation B16A.
Fuel Injectors
The fuel injectors from the original B16A must be used. The second generation injectors won't fit into the existing plugs, and have a higher impedence than the first generation ones. I am not sure whether the type of injector was altered (peak and hold vs saturation), but it is just easier to use the existing ones.
The second generation fuel rail is a different shape than the first generation one but can be used. Unless you managed to also get the second generation plastic holder that bolts onto the fuel rail for the wiring conduit, you will have to zip-tie the conduit to the fuel rail (because the original plastic one doesn't fit).
Oxygen Sensors
The EF9 ECU (PR3/PW0) requires two oxygen sensors. You need both of them because the ECU uses the reading from each O2 sensor fuel to determine the fueling for only 2 cylinders. Don't try to run a single O2 sensor because it'll just end in tears.
Exhaust Manifold
Becuase the EF9 ECU (PR3/PW0) requires two oxygen sensors, you need an exhaust manifold that will house both of them. Either use the existing first generation exhaust manifold or get a new 4-2-1 header with two bungs at the end of the primary collectors. Note that a 4-1 exhaust manifold is harder to get running right because of the requirement to have two O2 sensors. Newer ECUs from Honda use a single O2 sensor, which makes using a 4-1 header much easier.
Engine Mounts
The engine mounts for the EG6 Honda Civic are ever so slightly different to the EF9 Civic mounts. Not enough to really notice visually but enough that the second generation engine won't fit quite right without using the original EF9 ones.
Crankshaft Pulley
I can't clearly remember if this was changed or not, but we definitly took it off and re-used it for some reason...
Power Steering Pump
The second generation power steering pump has a different pully on it. Although we changed the pully over to the original one, it still wouldn't mount correctly because the power steering fluid line that bolts onto the top of the pump has a slightly different bolt pattern/arrangement.
Radiator Fan Switch
The location of the radiator fan switch in the second generation B16A is in the thermostat housing instead of in the back of the block. You need to extend the 2 wires that normally connect into the block so they can reach the new location. I am not sure if the plug is different because mine was smashed, but I would presume so.
Idle Air Control Valve (IACV)
The second generation IACV has a larger hole through which the bypassed air flows. This adversely affected the idle on the car because I couldn't get it to idle low enough (pesumably because too much air was getting through). With the original IACV the idle was fine.
Throttle Pulley
The throttle pulley on the second generation B16A is a different shape to the first generation pulley. Without using the original pulley we couldn't get full throttle because it wouldn't turn the butterfly far enough.