Originally Posted by Skippy

Let's see. You can buy a high pressure belt-driven CP3 pump for around $3000. It'll come with some soft and hard lines, and you can probably make or have fabricated your own common rail for a few hundred dollars. After that it starts getting expensive. I don't think there are any common-rail injectors that will fit the OM616/617 head, so you could either modify (most likely design and build a completely new one) head that takes an available injector, or design and build your own injectors to fit the head. I'm thinking a new-from-scratch head would be cheaper and easier. If you're good with design and have previous experience in internal combustion cylinder head design, you could probably come up with a working design in a month or two, less if you bang away at it full time.

Then you have to get someone to manufacture the head for you, unless you have a sufficiently good home shop to do it. With CNC, this is a lot less expensive for a one-off than things used to be, but I'd still expect to pay over ten grand for one head.

After that, you'll need to come up with some sensors, an ECM, and a fueling strategy. You could probably make it run with just a TPS, and a cam position sensor, but to come up with a really good fueling strategy, you'll need to be able to measure exhaust gas temperature and manifold pressure in real time, at least for R&D. Since you don't have to deal with the EPA, you'll have a much much easier time with your engine program than the OEM's do, but it's still going to be a lot of work to get it running the way you want.

So, short answer to your question, yes it can be done, but the cost in time and money would probably buy you a new Bluetech (at least).