A better bet, if you have the skills, is to go with Japanese power. Japanese horses aren't any more powerful than German horses, but they are generally much cheaper. Dollar for dollar, Japanese engines make more power. Now, the engine hole in a 318 Ti is shaped for an I-4 or an I-6, so narrow the candidates down to those configurations. In the affordable horsepower category, we have the Nissan SR20DET, the Nissan RB25DET, and the Toyota 1JZ-GTE. There are other options, but these three are available from used Japanese engine importers and will take you most easily into the 300-350 hp range.
Narrowing down the selection should go like this: Look at the oil pan on a six-cylinder E36 BMW and note where the deep part of the oil sump is. Pick the engine with the most similar sump layout. Making small clearance modifications to an oil pan is relatively easy. Relocating the sump and moving the pickup is another thing entirely.
Now all you have to do is fabricate engine mounts from scratch and mate a Toyota or Nissan engine harness to a BMW chassis harness. As I said, some skills are required. The BMW engine, if you are either content with less power or can afford big German horses, should bolt in and the electronics should plug in, if you steal the right harness.
Stupid Is As Stupid DoesOk, stupid question comin' your way: How do you figure out the displacement of an engine? Do you have an equation that might help me out?
Also, I'm tryin' to de-stroke my KA24DE and was wondering if you knew of any Nissan factory cranks that would fit. Also, what's the best way to go natural aspiration with it? I wanna get at least 8000-8500 rpm with it and still be streetable without problems with the crank, stroke, or timing chain. Any help is truly appreciated, thanks!Tony T.Camp Verde, AZ
Which question is the stupid one?
Displacement is easy, and instead of a formula, I'll just explain how to figure it out. If, like me, your memory is so bad you can't even remember your own middle name, understanding how to figure it out is better than memorizing a formula. All you want to know is the volume of the cylinder created by the bore and stroke. The volume of a cylinder is just the area of a circle times the height of the cylinder, and area of a circle is Pi x r2. "r", the radius, is just half the bore. Now, since you want the answer in cubic centimeters, you need to measure the bore in centimeters. Your 89mm bore is 8.9cm, so the radius is 4.45 cm. The area of that circle ( Pi is 3.14159 unless you're in Indiana) is 62.2 cm2. (cm3 = cc)
Now, the full volume of that cylinder is just 62.2 cm2 times the stroke, in centimeters. For your KA, that's 9.6 cm, for a single-cylinder displacement of 597.2cc.
Since you have four cylinders, the total displacement is 2,389cc.
Now for the stupid one: The answer is NO.
The KA24DE is designed top to bottom for low-rpm and midrange torque. There are plenty of KA24 race engines out there spinning high rpm and making power, but they only do so for one reason: They play by rules that say they have to. The compromises in driveability, durability, and most of all, cost are completely unnecessary when you're out in the real world with no SCCA telling you what to do.
No matter what your goals, you should always start with an engine that is inherently good at what you want it to do. If you want 8500 rpm, drop the KA24 in a lake and figure out how to install an S2000 engine. If you want to keep the KA24, replace the weak rods and pistons, lower the compression a bit, and turbocharge it with a modestly sized turbo designed to work well in the same low to mid rpm range the engine is already good at.
Either solution will work, but if it were me, I'd stick with the KA turbo.