Engines: Four Cylinders.

So because engine design has advanced so much in the last 40 years, there's a couple of Nissan four cylinder engines that we should look at.

The first is the KA24DE from the 92-98 240sx and the front wheel drive Altima.

Out of the box it's not that special of an engine. 2.4l of displacement. 165hp. Dual Over Head Camshaft design with a cross flow head (Intake and exhaust manifolds are on opposite sides of the head).

The real magic in this motor comes from building your own turbo system for it. Then you get this.

This is now a KA-T. As you can see almost all the engine weight is behind the strut tower. With proper tuning this engine is anywhere between 200-350whp depending on setup. There's no firm number because this is not a factory Nissan motor. Every KA-T is hand made so the quality and tuning are very inconsistent.

Positives

• Weighs almost the same as the original L26 and the weight is centered towards the rear of the engine bay helping balance and handling.
• No timing belt, uses a chain so lower maintence costs.
• Cheap. The base KA24DE motor can be found with a transmission for under $500. The turbo hardware can be put together for $500-1000. 
• Uses the same engine mounts as the other Nissan four cylinder.
• 2.4l means an insane amount of low end torque. The reason why this motor works so well is the low end torque pulls you off the line and when the torque wave ends the turbo boost kicks in. Think a surfer on a wave. The torque is the wave, when the surfer hits the water, he fires a jet pack.
• Cast iron block and head mean that if we want real high boost, upgraded crankshaft, connecting rods and pistons are all that's needed to reinforce the block.

Downsides? Well a few. First, since the KA24DE was not a factory turbocharged engine the internal engine parts aren't the strongest. They can handle low boost settings, but anything over 6-7psi and your going to need to replace the rotating assembly. Second is relying on alot of aftermarket and eBay parts for our turbo system. This is not a kit, it's get every little piece from different sources.

Let's talk about the other Nissan four cylinder. The SR20DET.

2.0l of displacement. Factory turbocharged engine. Makes between 210-250hp depending on the year. This is the equivalent of the 289ci Ford V8 in Japan. Anything you could think of doing has been done. This motor was produced from 1989 to 2005. Despite never being sold in the states, parts are still readily available for it over here. This engine is the heart of countless race cars, everything from D1 and Formula D drift cars to drag racers to countless Time Attack cars. These engines can make up to 400hp without having to be upgraded internally. 2.2l stroker kits and wise turbo choices can push it to 500-600hp.

So how does it fit in a S30 Z chassis?

Exacty like the KA-T because they use the same engine mount locations. The KA24DE and the SR20DET were both factory engine in the same car just in different countries.

So, positives.

• Sky's the limit. Anything you want to build, just open your checkbook and order away.
• See the notes on the KA about weight and position. Same here.
• Since the motor was turbocharged from the factory the internals are very robust. This motor was built to take a beating and keep screaming down the road.
• Fairly cheap. $1500-1800 for a complete running motor with transmission. That usually comes with manifolds, turbo, wiring and ECU. About 80% of everything you need to make it run.
• We trade the low end torque for a 7000 rpm redline. 
• Our 300hp goal is a new turbo and some better fuel injectors away.

Negatives? Not many. The big one is a problem for both motors. Is a four cylinder with a turbo an appropriate exhaust note for a 260z? More a matter of opinion. And how do these two engines stack up to our other choices?

Tomorrow we see what Toyota has to offer and we start talking 6 cylinder motors.