Mazda
B-Series Engine Swap FAQ |
| This engine swap FAQ details the differences between OBD-I Mazda B-series naturally aspirated 4-cylinder engines. This guide was created to help people making the transition from one B-series engine to another with ease. Sections: ----------------------------------------------------------------------------------------------------------------------------- I. Applicable Cars: This FAQ details how to swap any B-series engine into your Mazda vehicle. This guide is applicable towards the following models (possibly more): 1989-1993 Ford Festiva (1.3 SOHC 8v) ----------------------------------------------------------------------------------------------------------------------------- II. Stuff you should know about engine swapping: Before I get into the details about these engine swaps, I want to ensure you know what you are getting into. All of these engine swaps are VERY easy for a beginner to perform themselves in a 2-5 day period. It should not be difficult to do this swap as long as you don't run into any stubborn bolts. I'm not going to write a step-by-step process for removing and reinstalling the engine in this FAQ. You can perform any of these engine swaps with basic hand tools. You should have a screwdriver, set of pliers, and ratchet with set of metric sockets. All of the nuts and bolts on all of these engines are either 10, 12, 14, or 17mm in size with few exceptions. The axle nuts are 32mm (29mm on aspire/festiva) and are a ***** to remove without an impact wrench. Using a penetrating solution will aid in the removal of corroded bolts. Using high-temp RTV silicone gasket maker will ensure you won't have any leaks. You can even reuse old gaskets if you use this stuff, although it isn't recommended. Below is a list of suggested parts you should replace prior to installing your new B-series engine. ----------------------------------------------------------------------------------------------------------------------------- III. Parts you might want to consider replacing (in order of importance/necessity): -Oil filter & Oil: You spent all this money on a new engine, why
wouldn't you change the oil?
IV. Tips on buying a good used engine: Mileage isn't everything when it comes to used engines. Just because an engine has 40k miles on it doesn't mean its a better choice than the 110k mile one across the yard. Of course it is entirely up to you and your budget for an engine, but a good bet is an engine under 120k miles old. B-series engines are pretty damn robust and are built for turbocharging. Their cast iron blocks don't wear fast. The most notable problem with them is their tendency to have the famous "valve tap" issue due to the HLA system Mazda used in their BP models. Burnt valve seals also can cause the engine to burn oil, and there really isn't any way to tell if the engine has this problem without starting it up and revving it. Here is a quick & short guide on how to choose your engine: Always pop off the valve cover & inspect inside of the valvetrain: -If inside of head is SILVER.............the engine has been religiously
maintained, including the use of a high-quality oil that didn't varnish
the internal parts. This would be a rare find & great candidate to
install into your car. ----------------------------------------------------------------------------------------------------------------------------- V. B-series Engine Run down: This section quickly details which year/make/model each B-series 4-cylinder engine comes from, the HP and Torque ratings (from the factory) & fuel economy data on that vehicle. I also listed the weight of the vehicle in which the fuel economy data is from. This should help you calculate, roughly, what kind of fuel economy you can expect your car to achieve, if you compare your cars weight to the weight of one of these cars. I will refer to each of these engines by their engine code from this point forward: B3-E B6-E B6-ME B6-DE B8-ME BP-ZE One thing to note about all of these engines is the ECU and TPS differences between manual and automatic transmission cars. The throttle position sensor is different between manual and automatic transmission cars and will not interchange. Manual transmission cars have a 2-plug ECU while automatic transmission cars have a 3-plug. These ECU's will not interchange without serious splicing!! It is best to get an engine from a car with the same transmission that you have. ----------------------------------------------------------------------------------------------------------------------------- VI. Swap Information: As stated before, this guide is not going to include a step-by-step process for removing/installing your new engine. This section will outline the differences between the engines listed above and how you can fit one of these engines into your car. VI-a. Engine Mounting Points: 90-94 Protege & 323, 92-95 MX-3, Ford Escort GT & LX-E, Mercury Tracer LTS are all the same. You shouldn't have a problem interchanging motors between these cars. In the event you do need to change mounts, just unbolt the mount bracket from your old engine and bolt it to the new engine. Ford Festiva and Ford Aspire mounts will interchange with each other. The passenger-side mounting bracket from your B3 will directly bolt up to the B6-E and B6-ME engines. You will need to fabricate a custom passenger bracket if you plan to swap a B6-DE, B8-ME or BP-ZE to your Festiva or Aspire. The transmission mounts should be left untouched unless you plan to do a transmission swap. VI-b. Intake Manifolds: For 85-89 323, 89-93 Festiva and 94-97 Ford Aspire only. Unless doing a B3 to B6 (from older 323) swap, you will need to use the intake manifold from the engine you are putting into your car. Since your car has its intake routed over the top of the valve cover, you will need to figure out a way to rig a drivers-side mounted air cleaner assembly to your car. The MX-3 B6-ME comes with an intake tube that will allows you to rig the air cleaner to the side with ease, but you WILL have to relocate the battery, or go with a super-small sized battery to provide enough room for the aircleaner assembly. You can NOT interchange intake manifolds between these engines, the water coolant jacket locations and intake port locations are different on almost all of the B-series engines VI-c. Exhaust Manifold: Unlike Honda B-series, Mazda B-series exhaust manifolds (headers) DO NOT interchange between each other. This means you will need to use the stock exhaust manifold from whatever engine you are installing into your car. If there are headers available for that engine, then you are in luck, but headers are hard to find for any engine besides the BP-ZE, unfortunately. VI-d. Engine Wiring Harness: To simplify my findings, I made a list of three different style engine harnesses that are used for the non-OBDii B-series engines: Style "A": Style "B": Style "C": Unfortunately, I am unsure of what the 94-95 Mazda MX-3 has. I have a
hunch it has the "Style B" harness. Another thing to note is that all 1996 Ford Escorts and Mercury Tracers have an OBDii engine harness which is very different from the OBDi version. While there weren't many of these cars made, it might be very difficult to get your OBDi harness to work with the OBDii engine without swapping out all of its sensors. Now that you know the differences in each wring harness, it should be easy for you to wire your new engine using your harness. Here is a quick rundown: Style "A" to Style "B" Engine: you will need to get the IAC valve connector from the style B harness and splice it into your existing harness. There is a thicker wire and a thinner wire, just splice the thick and thin wire from the connector to the thick and thin wire on your harness. You will also need to remove the fuel injector harness from you new engine and reuse your old fuel injector harness to ensure the TPS works. Style "A" to Style "C" Engine: You will need to do everything listed above and also get the two-wire connector from the VICS solenoid and route those two wires all the way to the two pinouts on the BP ECU you are using. You will also need to get a 4-wire distributor connector, and splice the three wires from your old harness, and route the forth wire to your new BP ECU. Style "B" to Style "B": No splicing is necessary! Style "B" to Style "C": You will need to get the two-wire connector from the VICS solenoid and route those two wires all the way to the two pinouts on the BP ECU you are using. You will also need to get a 4-wire distributor connector, and splice the three wires from your old harness, and route the forth wire to your new BP ECU pinout. VI-e. ECU & TPS Notes: Be sure to use the ECU from the car your new engine is from, otherwise the engine will not run at it's full potential (if at all). One thing to note is the differences between manual and automatic transmission cars. The TPS is different between these cars and will not interchange. 5-speed cars have a 2-plug ECU while Automatic transmission cars have a 3-plug ECU. Interchanging these ECU's will require serious splicing, so be sure to get the proper ECU for your car. It is also easier to get an engine from a car of the same style transmission to avoid the TPS interchangability problem. ----------------------------------------------------------------------------------------------------------------------------- VII. Transmission Information: To clear up any confusions, you must understand that all of the cars listed above have transmissions that will directly bolt onto ANY of the engines in this FAQ. YES YOUR TRANSMISSION WILL BOLT UP!!! Now that you know that, you might be wondering about possibly swapping your transmission for a stronger G-series transmission. If you have a 323, MX-3 or Protege DX, you have a Mazda F-series gearbox. This transmission should hold up well to any of these engines. It has taller gear ratios which are geared for fuel economy over performance and smaller, 22mm diameter axles. It has been known to hold up to about 200 horsepower and ft-lbs of torque without reliabilty issues when not abused. The Protege LX, Escort GT & LX-E and Tracer LTS all have G-series transmissions. These transmissions are used in numerous Mazdas including all 2.0 4-cylinder & 2.5 V6 MX-3, MX-6, 626, Ford Probe and 01+ Protege's. They have been known to hold up to over 300hp and ft-lbs of torque when not abused. They use 24mm axles and utilize an intermediate shaft to reduce torque steer when accelerating off the line. All G-series transmission have either a 4.11 or 4.39 final drive ratio and short gear ratios for quicker acceleration at the expense of fuel economy. To swap a F-series for a G-series, you will need to get the axles, intermediate shaft from a 90-94 Protege LX, 92-94 MX-3 GS or 91-96 Ford Escort GT/LX-E or Tracer LTS. The hubs & brakes do not need to be swapped out on any of these vehicles. Swapping the other parts out will allow you to use one of these transmissions. Be sure to get the transmission mount brackets & mounts when you buy your transmission as they will be needed to mount it. Clutch & Flywheel Information: There are 5 different sized clutches worth noting that can be used on these engines. Here is the list: B3-E: 7 1/8" Clutch Disc, 18-spline shaft, 3/4" hub The 20-spline shaft clutches are for F-series transmissions only. You *should* be able to use the bigger-sized clutch on a B6-E or B6-ME flywheel for more clutch holding power, although it has not been confirmed. The 22-spline shaft clutches are for G-series transmissions only. You can use the bigger-sized 8 7/8" clutch from the Ford Probe / Escort on a stock BP-ZE flywheel for more clutch holding power. The flywheels from all B-series engines will interchange with one another and use 6-bolts to secure them to the crankshaft. K-series V6 engines use a 8-bolt flywheel and thus are not interchangable |