Basics of swapping a modern engine into our vintage chassis.

Once we decide our engine and transmission we have to mount it safely in our chassis. lets look at the finer points of the swap process.

Engine and transmission.

• All of our engine choices fit very well so there's no frame modifications to be made. All of the engines have the same basic mounting process. We buy a custom made engine cradle and weld the cradle into our chassis.

• Pictured to the right is the engine cradle and crossmember for the VQ35 swap. The grey cross bar welds on top of the frame acting as a brace stiffening our chassis and the red stands bolt to the motor and the cradle.

• Here's the cradle installed with the motor in place. Notice the factory crossmember has been notched Basically, a section was cut out with a plasma cutter then it was boxed in so it's still stiff. Since the engine cradle acts like a crossmember the factory crossmember is only there to hold the steering rack and for the lower suspension to attach too. The VQ35 is the only swap that requires that.

• Transmission mounting is simple, that black bar is a transmission crossmember style mount. Once the engine and transmission are in place the transmission mount bolts in.
• The driveshaft will probably need to be made. The transmission will need either a splined shaft or a flange on it, and our differential will need a flange on it. The length of the driveshaft all depends on how long of a transmission we use. It's easy to measure and shafts are easy to get.

Once these steps are done the engine and transmission are physically mounted in place and are good to go.

Cooling.

• Now that are engine is mounted, we need to run coolant through it. Again, this process is fairly similar to all engines. Mount a correct thickness radiator and run coolant hoses to engine. Depending on how far away our engine is (V6 or Four cylinder) we might need to make coolant pipes since 3-4 foot straight radiator hoses will be more likely to fail.
• Once the radiator is plumbed in, we need to make heater hoses to go to the heater core in the cabin through the firewall. While we most likely won't have A/C with our swap we will retain the heating system. This is optional, but I feel like there's no reason not to take the time and have a working heater.
• Depending on our engine there will probably be little cooling lines to the manifolds and throttle bodies. These will most likely come with our engine.
• Not only do we need to cool our coolant, but our engine oil as well. True vintage racing car shakotan style is to have an external oil cooler mounted on the outside of the bumper.

Not sure if we'll go this extreme for daily driving use, but a small wire mesh cover on that cooler would protect it from small rocks and debris.

Electrical.

• To start with all of our wiring is 40 years old and from a time where electricity was dark magic created by time wizards and cased in black boxes. We know more about automotive electrical now, so we can make sure we have enough and it always works. Ask a vintage British car owner about their wiring and they'll either punch you or sob quietly in a corner mumbling about "points" and "tube fuses".
• All of our engines are fuel injected with computer controlled ignition. Our original car was carburated with points style ignition and distributors. In order run our new engines we need to run new thicker wires and connectors. The engine will come with a wiring harness that will connect to an Engine Control Unit, or ECU. The ECU will need constant 12v, switched 12v (ignition switch) and a chassis ground. We're going to mount our battery in the trunk so all these wires will be custom cut for our chassis. 
• The VQ needs a lot of other wiring done, but it's all simple once the parts are together. All the extra unused control modules and wiring just need to be connected to the ECU. We can zip tie them together and tuck them behind the sash board.
• The basic idea is to have two wiring harnesses for the car. A chassis harness that controls lights, radio,  and accessories and a separate engine harness that powers the ECU and starter. our gauges will be tapped into the engine harness for their input signals and into the chassis harness for their power.

Fuel.

• Because we have a 260z we have a fuel tank from the fuel injected 280z. That means it is already baffled. Under hard cornering 240z's would get fuel starvation because the fuel pick up would dry out. This doesn't happen with 260/280z fuel tanks.
• Our original system was carburated with a mechanical fuel pump that operated at fairly low pressure. The more fuel was needed, the higher the pressure would go. Even at its highest flow rate the factory pump was very low pressure, about 8psi. A fuel injected motor needs 40-45psi at the fuel rail. A simple frame rail mounted electronic fuel pump will provide as much fuel as we need.
• One or two hard fuel lines will have to be made and run from the fuel pump to the engine bay. Then braided soft lines from the hard lines to the fuel rail. The number of lines depends on if the engine needs a fuel return line or not.

Exhaust

• Depending on whether or not we have a turbo the exhaust is fairly easy. All of our engine choices have exhaust manifolds that fit in our bay. 
• I'll be detailing our muffler choice later because it needs to be period correct since it will be visible during everyday use.
• We need to make one or two pipes that will go from the outlet of the factory manifolds and terminate at the rear muffler. This exhaust will be sectioned with flanges so that a resonator can be bolted in to control sound levels if needed. If we run a turbo, piping will be 3" wide with as little bends or restrictions as possible. No turbo's means slightly smaller piping.

So with those all addressed we will have a car that moves under it's own power. Not done, but at least it would move and drive.