Engine dyno for EFI project

[DAVE MORRILL HPL DESIGN ENG 207-775-8574]

Hello,
	Does anyone have any tips or plans on how to build an engine dyno? 
Before I start my efi project I want to build a dyno so I can benchmark my
results and debug the system in the shop.  
	I initially began thinking about using a disc brake for a load, and
measuring the torque-losses on the pad to get an approximate torque measurement
Even had a method to calibrate w/ a torque wrench.  The numbers would not be
exact but at least I would be able to see relative improvements as I made
changes to the efi system.
But then I though about a cast iron disc spinning at >7000 RPM and did not feel 
like this was very safe, heat and wear would be significant probs as well,
 - any comments ?  

I guess the industry uses a water pump for a load, I'm not sure how to do the 
calculations, do you use water pressure as a measurement, flow rate of
liquid?  What method could be used to calibrate?  Any advice on where to get an
applicable pump?

thanks,
	Dave.