Well... unfortunately Automation has no plans to add in diesel engines at the moment. So you might be out of luck there... granted you can make an engine sound like a diesel engine if you use the same geometry (or as close as you can get) with the bore and stroke (as that is where it really matters) As for what you just stated... that tells me you might not be really up to snuff on how engines generate their sounds. The Detroit 4-71 is a crossplane engine rather than a flat plane engine like most 4 cylinders. Since it is a 2 stroke that means you need a power stroke every 90 degrees rather than every 180 degrees rotation to get smooth operation. If they used a flat plane crank on a 2 stroke 4 cylinder engine, that would end up running like it was a 2 cylinder... and since there are 4... might as well smooth it out somewhat. The V8 engine again hits with every piston every time thus why they sound rather smooth when running The V16... same story... So it is literally just 4 4 cylinder engines stuck together as its just 2 v8's stuck back to back and the v8's are just 2 4 cylinders in a V.
I might just record the v8 diesel sound from the d/h series/ roamer into audacity and do it that way or look at good videos to get the sound from
