Originally Posted by Fabrik8

Look for eddy current dynos, they will generally give the best load characteristics and repeatability. The can be programmed to run a set routine also, which is used a lot with race engines. Using existing track data, the dyno can be programmed to run an engine through an entire track worth of load/RPM data over and over.
Eddy current dynos are also the most expensive though, because of the cost of the dyno brake itself and the sophistication of the controller required. You can kind of think of them as a big electric generator with the ability to vary the torque load.

I work in an engines lab, and all of our natural gas and deisel engines are run on eddy current dynos. Many of the engines are over 20 liters, so we're talking some pretty big stuff here.

So I guess to better answer your question, try Mustang. Some of our smaller and less accurate dynos (read: cheaper), which are in the power range you are looking for, are Mustang eddy current dynos. I guess I should put a disclaimer on that: "Less accurate" when compared to the accuracy of the really expensive stuff we use too. Kinda like saying a Champ Car is a cheaper, less accurate F1 car.

Most of the engine parameter measurement is more part of either the dyno software, or datalogging software, and might not even be included depending on the brand and type of dyno. A lot of the parameters you are talking about can be either taken right from the ECU, or can be gathered with a second set of sensors on the engine. Dyno controller software will usually give input shaft speed, HP, torque. The rest of what you would want is completely dependent on what other bells and whistles are included in the software.
The level of cost or sophistication doesn't necessarily mean anything either. The really high dollar stuff that we have, with Hewlett Packard rackmount controllers and stuff like that, doesn't come with datalogging software. That's fairly common for non-aftermarket stuff, because the chances that you'll be able to use some pre-packaged software solution outside of an aftermarket performance shop are very slim. We write our own software.

Basically engine parameter measurement isn't necessarily tied to the operation of the dyno itself, and may require separate hardware and software, so keep that in mind. If you're using diesel engines out of production vehicles, something meant for an aftermarket shop would probably work fine, including datalogging/display software.

I guess really you're probably looking for a complete test stand, not just a dyno.

Originally Posted by Fabrik8

What do you mean by "engine performance"? Depending on what you're actually testing for, you might be able to get away with a very basic type of load cell such as a water brake. I guess what I'm asking is whether you're comparing types of dynos (eddy current, water brake, AC/DC, etc.), or brands/models of dynos. I guess it's hard to help because we don't really know too much about the specific things you're testing for. If you're doing basic power output testing, a simple water brake could work perfectly fine, but if you're doing something tricky like running load sweeps to bring the engine in and out of the knock region, you might need something with more tricks. That's why I have a hard time with the "optimal" part...

I'm assuming you're going to be running something similar to standard dyno pulls while measuring torque and EGT as the primary criteria?