This was all done in the driveway of my good friend Conrado Freites, who was really the automotive master sergeant in this process, guiding me through the labyrinth of vacuum hoses and crankshafts, in addition to allowing me the use of his shop. Conrado was an excellent teacher. While I could never have done this on my own, I am now confidant that I can at least muddle my way through whatever the little car throws at me next.
I naively called Pete, and asked about installing the M3 engine. After all, it was supposed to be relatively straightforward, and many vendors will sell you the engine from a wrecked M3. However, there are several problems. For instance, the M3 aircleaner won't fit in the '02 engine bay, and you have to fabricate one. Also, since the M3 uses sensors on the crank for ignition and tachometer, you have to modify your 320i 5-speed to accept the sensors (the other option was to install an M3 transmission, which involved way too much cutting and fabricating for my tastes). What about motor mounts? Oil pan clearance? Cooling system? And while you're at it, how are you going to connect the M3 wiring harness to the 2002 harness, and the M3 header to your 2002 exhaust? Pete McHenry has worked out the M3 installation over the past several years, and has developed an installation package that has the answers to these and many other, unforeseen problems. The combination of Pete's knowledge on the subject, reputation, and willingness to take phone calls at odd hours convinced us to get our M3 engine from Pete, as well as his installation kit. Many hours later, I am convinced that this was the right decision. Late at (many) nights, it was reassuring to know that someone had done this before, implying that there was a good chance that this crazy scheme would work.
I ordered the engine and install kit from Pete, shipped him our 5-speed transmission for addition of the Motronic sensors, and proceeded to prepare the car for the new engine. Conrado and I removed the defunct '02 engine, and prepared the engine compartment for its new inhabitant. The first thing to go was the battery, since it is located where the airfilter of the M3 engine will go. Import Engineering (North Hollywood, CA) makes a nifty combination rear shock tower brace/battery mount for the trunk, which consists of a battery pan incorporated into a strut brace, like an inverted triangle, so that the battery is mounted ahead of a line connecting the two shock towers. This moves the battery up forward, leaving you with most of the trunk for storage. Some deft work with the acetylene torch by Conrado then removed the battery tray from the engine compartment, and the residual metal was ground down and painted.
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The next thing that was changed was the fuel system. The carborated 2002 used a plastic low pressure line for fuel feed, and a steel line that ran under the driver's side of the car for the return line. The fuel injection is going to require high pressure, so the steel line was used for feed, and the low pressure line was used for return. The gas tank vent line was kept, and fed into the aircleaner. To get the higher fuel pressure, the prepump from an '84 318i was mounted in the '02 gas tank, and fed a tii main pump with accumulator, which was mounted under the right half-shaft. The two pumps were connected by a large (13 mm ID) hose that just barely fit through the hole in the frame from the tank to the tii pump under the car. The pickup of the prepump may be slightly too long for the '02 tank, in our case we had to compress the foot slightly, using the attachment screws that hold the pickup onto the stalk. A 3-series fuel filter mounted under the left half-shaft complete the fuel system modifications.
About this time the M3 engine arrived from Pete, and it was spectacular, a true gear-head's delight! Fresh black crinkle coat paint on the intake manifold and valve cover, with the raised " M POWER" lettering in clear-coated aluminum. The engine came with an M3 clutch and 323 throw-out bearing, and bolted right up to our 320i 5-speed transmission. Coupled to the 1:3.90 limited slip differential (from a 320is), the driveline would be complete. We rented a hydraulic crane, and dropped the engine in, bolted down the engine mounts, and called it a night. The real difficulty came when we installed the transmission the next day. Since the engine was a bit bigger than the 2002, and since the transmission now had a sensor mounted on the bell housing for the Motronic pickups, things were a tight fit. Conrado and I had to unbolt the engine mounts and jack up the engine to get it aligned with the transmission, which we juggled for quite some time before the spline engaged with a reassuring, thunk! A few desperate bolts later, and we had the transmission bolted to the engine, and the engine bolted back to it's mounts. Pete supplied a 2002 oil pan to which he welded baffles, so the engine fit into the 2002 perfectly.
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Back in the engine compartment, we test fit the aircleaner Pete had supplied. Pete had provided a rubber elbow for the inlet to the intake manifold, to which was then attached the airflow meter, and a cylindrical K&N free-flow airfilter (for a 5 liter Mustang). The K&N didn't fit in the engine compartment, but actually projected about an inch in front of the forward wall of the engine bay. The position was marked on the wall, and the acetylene torch made another appearance to cut the hole. About an hour of grinding resulted in a hole with about 1/2 inch clearance on all sides of the aircleaner. The metal was painted, and lined with plastic molding to protect the aircleaner. The aircleaner projects to just behind the front grill. It is not obvious unless you look for it, and provides great quantities of cool air for the engine. This was just one example of Pete McHenry's simple yet efficient solutions that made this transplant a success.
Another wonderful item that Pete provided with his installation kit was a wiring diagram to connect the wiring harness on the M3 engine with the 2002 body, and all electrical connections on the M3 harness came clearly marked. This was one of the best parts of dealing with Pete, as I was most overwhelmed by the thought of figuring out the 20-year old wiring of my car and mating it to the new engine. The electric fuel pumps were powered by a single powerline from the M3 harness that was run to the back of the car and split for the pump and the prepump. Jim Dowd (BMW parts locator) provided the wiring harness for a tii fuel pump, and the wiring was run from the tii pump up into the trunk to join with the prepump. On Pete's recommendation, the return inlet on the 318i prepump was plugged, and the return inlet on the '02 gas tank was used.
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Back in the engine compartment, the cooling system was next installed. This required a 320i radiator, and because the engine is really shoe-horned into the engine bay, an electric fan must be used that mounts in front of the radiator. An M3 thermostat was used, and Pete provided a diagram illustrating the cooling connections. This was probably one of the trickiest parts of the installation, and required many trips to the NAPA store to get the correct hoses. We looked at the bends required, bought whatever was in the NAPA catalog that looked close, and cut the hoses to fit. After several frustrating trial and error adventures, the cooling system was finished and coolant was added. The electric fan is controlled by a Bosch relay and a 91 degree temp switch in the thermostat. So far this has resulted in adequate cooling in stop and go traffic even in the heat of a Miami summer. I also use Redline Water Wetter, and it seems to help cool the little bimmer.
Pete also provided a custom throttle-cable, and this was installed next. This required only minor adaptations at the pedal box to mount a bracket, and we were ready to crank up the engine. A hole was cut in the firewall, and the computer was mounted in the standard glovebox
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position. After replacing some defective wires in the electrical harness, the engine finally crackled to life, a wonderfully ordinance-breaking roar through the open exhaust header. Connecting the exhaust was the next task. Pete provided a collector for the M3 header so that a single pipe 2002 exhaust system can be used, and on Pete's recommendation we used a factory 2002 turbo exhaust. This is well made, fits perfectly, and sounds great. However, given the cost of the turbo system, and its increasing "NLA" status, a viable alternative is to run a 2.25" pipe, using your choice of resonator and muffler. In stricter emission states, a catalytic converter could be substituted for the resonator. The only problem hooking up the exhaust was that the M3 header emerged on the passenger side of the car, offset from the rest of the exhaust system. However, a trip to the local muffler shop fixed this problem. They bent a 2.25" pipe with two 45 degree bends (like a relaxed 'S') and connected the header collector to the turbo exhaust system.
Finally, a new front stress bar was needed that could clear the throttle linkage of the M3 engine. Fortunately, I was looking at some '02 pictures on the 2002 homepage on the internet, and saw Stanely Phan's car. Stanley had a stainless steel stress bar made by Carl at La Jolla Independent BMW which curved back to clear the OEM aircleaner. It looked like it might fit, and a quick call to Carl confirmed that it would indeed clear the M3 engine, and suddenly the stress bar dilemma was over.
One disadvantage with the M3 engine was that the shifter vibrated and buzzed over 3500 rpm. This problem has been associated with the E30 M3 engine, and a new quick shift kit from Metric Mechanic (Kansas City, MO) solved this dilemma. Also, while installing the new shift linkage we noticed that the top of the transmission bushing from the old shift linkage was worn from rubbing on the lip of the transmission mount. A few judicious blows with a hammer solved that problem, and the car now runs buzz-free.
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