Fuel Injecting Your Lancia Scorpion
by Mark Rawlings
Having just completed a third twin cam fuel injection conversion and about to embark on my fourth, I decided it was time to write down my experiences for the benefit of other Scorpion owners. I'm sure there are plenty of you, who, like myself, have invested in everything from exhausts to cams, but are still not satisfied with the performance or drivability of your car. After removing the smog controls, changing the cams, carburetor, and exhaust of my first Scorpion, I still had a car that idled erratically and occasionally stalled at stops. And the performance wasn't up to my expectations either. That's what convinced me to remove the entire engine and replace it with a 2.0 liter Beta engine complete with 85mm 9.0:1 pistons, 40:80 cams, Prima Flow exhaust, and most significantly, fuel injection. I ended up with a car that can accelerate in fifth gear from an idle to the redline, and starts and idles without a glitch! The other two conversions were on a stock 2.0 liter 1979 Fiat Spyder 2000 and a friend's essentially stock 1976 Lancia Scorpion, both of which resulted in dramatic improvements in both performance and drivability.
Installing a fuel injection system on a Scorpion is a straightforward project requiring a minimum of fabricating. The fuel injection system can be installed onto the stock Scorpion head without any modifications, or any head in the twin cam family for that matter. The fuel injection system requires neither the air injection nor the exhaust gas recirculation system to meet emissions. It will operate with or without a catalytic converter. The fuel injected Scorpion will run cleaner than the stock engine, but may require special smog certification in your state.
DECIDING WHICH SYSTEM TO USE
The decision whether to use a Fiat or Lancia fuel injection system may most likely be based on which system is available to you. Both systems are basically the same in function but not in layout. Given a choice, the Lancia system from the Betas has several advantages over the Fiat unit used on the Spyders and 131s. Because the Beta system is from a transverse engine car, it maintains a factory installed look when installed in the Scorpion. The air filter, alternator and the air conditioning compressor retain their stock locations whereas the Fiat unit requires relocating the air filter and was generally designed for a longitudinal engine installation. Perhaps even more importantly, with the Lancia system, all but one minor part can be obtained from one donor car. The Fiat system, on the other hand, will require getting cams, housings, and distributor from a fuel injected Beta if you wish to keep the spare tire in its stock position. Although the Fiat conversion requires less fabrication, I personally would choose to use the Beta system. It's well worth the extra effort, and the finished product looks so original you'll wonder why the Series 2 Monte Carlos didn't come that way from the factory.
This article will be concentrating on the installation of the Lancia Beta fuel injection system, but it will generally apply to the Fiat system also. There are several fuel injected Scorpions running around with the Fiat system, but I personally don't know of any with the Beta system. Therefore, I felt it would be more worthwhile to highlight the procedure.
PARTS ACQUISITION
Below is a list of parts you will need to obtain from a donor car. If you are purchasing these parts from a wrecking yard, it may be most cost effective to simply purchase the entire engine, or, in any event, try negotiating a lump sum price for all the parts.
Parts to remove from the donor car:
1. Fuel injection wiring harness. The fuel injection system has its own harness that attaches to the cars electrical system by way of the dual relay.
2. Electronic control unit (ECU). More commonly known as the brain or black box. Mounted under the dash on the passenger side.
3. Dual relay. Mounted in the engine compartment on the right side near the firewall and fuse box. It has two connectors plugged into it. The one with white wires is a part of the fuel injection's wiring harness. The other one leads to the car's wiring. Be sure to get this connector along with a length of wire.
4. Water temperature senders. Located on the steel water tube bolted to, and running along, the center of the head.
5. Air flow meter. Mounted next to the battery.
6. All hoses located between the air filter and the intake manifold.
7. Intake manifold complete with injectors, fuel rail, pressure regulator, throttle linkage and throttle cable.
8. Engine crankcase breather hose located on intake side of the engine.
9. All miscellaneous hoses connected to the auxiliary air regulator, distributor, air conditioner fast idle valve and heater vacuum canister.
10. Fuel pump and filter including brackets. Located underneath rear of the car near the fuel tank.
11. Both cams including their housings, covers and wheels.
12. Distributor including its mounting plate, rotor and coil.
13. Auxiliary air regulator.
14. Air conditioner fast idle valve.
15. Lambda sensor from exhaust.
MODIFICATIONS
Briefly, the most significant modifications required are to the throttle linkage, the vertical section of shift linkage, and to the fuel injection wiring harness. These are straight forward and can be accomplished by anyone processing average mechanical skills and the necessary tools.
THROTTLE LINKAGE
The modifications to the throttle linkage are the most extensive. It is an assembly that mounts to the intake manifold. When the throttle is actuated, a short linkage rotates the throttle butterfly. However, due to the close proximity of the Scorpion's fire wall, this assembly must be replaced with a more compact unit. The diagram below shows what the new assembly looks like. This new linkage accommodates the throttle cable and mounts the throttle position switch in place of the pre
heat unit. It also requires fabricating a new, longer throttle shaft to accommodate the throttle position switch in place of the throttle pre
heat unit. This shaft can be obtained from a Volvo, although I do not know the specific model.
SHIFT LINKAGE
The vertical shift linkage that extends from the cross member at the bottom to the fire wall at the top must be offset to clear the fuel injection intake manifold. This is accomplished by removing an 8
5/8" section and offsetting it 1
1/8". To maintain proper alignment of the pieces while offsetting the 8
5/8" section, the linkage should be tack welded to a make
shift jig which will hold the two ends in position while the center offset is being made. By doing so, all critical dimensions can be maintained. The diagram illustrates the before and after differences. Fabricate the offsets from 1/4" by 1" stock.
WIRING HARNESS
Because the various fuel injection components are being mounted in different locations than originally, some sections of the wiring harness will have to be either lengthened or shortened. It is best to make the appropriate modifications to the harness after all the other components of the fuel injection system have been installed. This way it will be easier to determine how much the individual wires must be lengthened or shortened.
The ECU and dual relay should be located inside the car. I suggest mounting them either above the glove compartment or in the right side kick panel. It can also be located under the passenger seat providing there is adequate clearance but it can possibly get wet if your car leaks. In either case, the harness will have to be lengthened. Cutting the harness about six inches from the ECU's connector and splicing in the extra length will eliminate having to buy the special terminals fitted in the ECU's connector. Although the wires are numbered, I suggest cutting only one wire at a time just to make sure you don't accidentally confuse two wires.
The dual relay is the fuel injection's link to the cars electric supply. The terminals on the relay are numbered for reference. Terminal 88d should be connected to the fuel pump's positive terminal. Terminal 88z connects directly to the battery's positive side. Terminals 86a, 88y, and 88c connect to wires leading to the ignition switch. 86a connects to the ignitions terminal 50 and is hot when the engine is Banking. 88y connects to terminal 30 and is always hot. 86c connects to terminal 15 and is hot when the key is in the drive position.
MISCELLANEOUS MODIFICATIONS
The fire wall must be dented slightly to allow adequate clearance for the idle adjusting screw located on the intake manifold's throttle valve. Locate the area by holding the throttle valve near its location on the intake manifold. Use a hammer and dolly to depress it approximately 1/2". Check by installing the throttle valve on the intake manifold.
The two water temperature senders need to be located near the engine. By utilizing a water outlet housing from either a fuel injected Spider or 131, you will have a mounting place for one sender as well as for the auxiliary air regulator. The other sender is installed on the "tee" section of the water outlet. This requires having a piece of aluminum welded to the top of the housing and then drilled and tapped to accommodate the sender.
The air flow meter is installed inline between the air filter and the intake manifold's throttle valve. To allow for a straight line between the two, the top of the air filter canister needs to be rotated slightly toward the fire wall. To do so, the small alignment stub must be removed to allow the lid to be rotated into position. Next, a simple bracket needs to be fabricated to support the meter. This bracket is nothing more than a piece of 1/8" plate aluminum that mounts to the engine compartment lip and is drilled to accept the air flow meter. See the engine compartment diagram below. A short section of hose cut from the Scorpion's air filter hose is clamped between the filter housing and the air flow meter. The Beta's rubber air intake duct will have to be shortened and some of the ribbing ground off so a bandclamp can be installed. After you have the airflow meter and the intake manifold installed, attach this duct to the throttle opening. Align it with the air flow meter and mark its approximate length. Remove and cut it. Now, using a grinder or rasp, remove the ribs from the last one inch so a band clamp can be installed. Take care to insure that the hose is not cut incorrectly, as new hoses are not available.
A new throttle cable needs to be fabricated including its sheath that connects to the end of the throttle tube running down the center of the car and to the throttle linkage mounted on the intake manifold. The new sheath has its lower end like that of the Scorpion's and its upper end like that of the Beta's with a threaded adjustment shaft. A new inner cable must be made because the original one is not long enough.
The Lambda sensor should be installed in the exhaust down pipe directly below the exhaust manifold. Drill a hole and weld a nut of the appropriate size over it. If headers are being utilized, weld the nut to the header at the point where the four runners collect. The wire leading to the oxygen sensor needs to be lengthened using a special shielded and high temperature wire available from JGM Automotive Tools. I have heard that the engine will not operate correctly without the Lambda sensor. However, I drove my fuel injection Fiat Spyder for almost two years before I installed an oxygen sensor. I couldn't tell any difference in performance or drivability. However, I may have just been lucky.
INSTALLATION
Prior to jumping into the installation of the fuel injection system, I highly recommend that you first prepare all the necessary modifications. This will result in less down time and will permit assembly to progress more smoothly. The shift linkage can be modified and then reinstalled while other parts are being worked on. Even the wiring harness can be lengthened into the car and the ECU and dual relay installed. Likewise, the temperature sensors can be mounted on the engine prior to the actual conversion.
Once you have everything modified and ready for installation, begin by removing the stock intake manifold and carburetor assembly. If your timing belt hasn't been changed in a while, I suggest removing the complete head and disassemble it on a bench. You will be changing the cams, housings and adjusting the valves. All this is more easily accomplished with the head off the car. You also will have better access for fuel pump and filter installation. While you are at it, why not replace those pistons with some 9.0:1's. They can be easily replaced on the Scorpion without removing the engine. Or, at least replace the head with one from a 1592cc 1973 Fiat 124. This will also increase the compression ratio. Doing both will yield approximately 10.0:1. In any case, continue by removing the air filter, fuel pump, filter and fuel lines, and all smog assemblies.
Now it's time to start installing the fuel injection pieces. Start with the fuel supply system. Mount the fuel injection pump in the original pump's location. The mounting holes are spaced differently, but a rectangular piece of steel or aluminum plate can be fastened to the car and the pump to it. Mount the fuel filter on the under side of the parcel shelf on the far right side of the engine compartment. Install the Beta cam housings, cams and distributor to the head you will be using. (Don't use the 2.0 Litre Beta head on your Scorpion engine unless you want to drop the compression to about 7.0:1; not good unless you're adding a turbo also!) Install the fuel injection intake manifold with it's special extra thick gasket. Bolt the head to the block and turn your attention to the throttle cable. This requires threading the new cable in from the accelerator pedal. Adjust it's length and check for complete opening and closing.
Mount the air flow meter to it's plate and bolt the assembly to the engine compartment lip. Modify and install the air intake duct as previously described. Connect all miscellaneous vacuum and fuel lines using new high pressure hose for the fuel delivery.
By this point all that's left is the wiring harness. Begin by identifying all connectors with their respective components. Then lengthen or shorten each lead as appropriate. The special connectors are available from JGM Automotive Tools.
Hopefully, these instructions are clear and concise enough for you to perform the conversion described. I have already given this article to two individuals who have completed the conversion. Please feel free to call or write me if there's any
questions I can answer:
Mark Rawlings JGM Automotive Tools
3722 Spanish Gate Drive 5692 Buckingham Dr.
Newbury Park, CA 91320 Huntington Beach, CA 92649
(805) 499-0710