Paul et al,


The recent TTC engine run postings, turbo compound threads, and my own
efforts have started me thinking about an engine test stand and the
features/performance it should demonstrate.


Obviously a control/instrument panel would incorporate some of the basic parameters like...


 oil pressure

 oil temp

 engine (coolant) temp

 exhaust temp

 manifold pressure

 air/fuel ratio

 rpm

 throttle position

 fuel flow/totalizer

 time

 hobbs


 throttle

 mixture

 ignition



What other controls/measurements should be incorporated on a basic level?


What about on a more advanced, special situation level (e.g. waste gate position when testing turbos)?


Should it be easily transportable?


And what about safety features (fire extinguishers, kill switches, etc.)? What do you suggested?


Ideally a data acquisition and control system would collect, log, and display the data. I use National Instruments LabVIEW software and hardware (along with other manufacturers like Omega, Interface, Banner, etc.) for such at work. But it looks like other solutions are available through some of the systems discussed in postings here. Personally I'd prefer to use something available and proven in order to get to the engine testing instead of debugging I/O systems (even though I do that a lot with NI LabVIEW!!). What is available and what are your thoughts on that?  There are many automotive type test stands out there for basic run in testing. But I would expect an aircraft test stand to measure torque and thrust for a prop generated load. Not too many (none???) out there that I saw, but please let me know about any that you know of.


Is there any sort of "standard" test prop that would be suited for initial or comparative testing?


A DIY stand seems more practical from a cost and achieving desired capability standpoint.


Therefore, what would be a good upper limit of each value to start sizing a stand?


 Max engine torque = ?

 Max engine thrust = ?


Obviously the answers to my questions are very subjective with many variables and personal preferences that could affect the answers. At this point I'm just looking for some rough initial numbers for the upper limits and capabilities that "amateur home builder" folks like us might like to see a stand incorporate.


I think the TTC engine might be representative of such performance limits? Yes? No?


And what are the thrust and torque goals for TTC?


Is anyone else interested in building such a stand?


So put on your thinking caps, let your imagination run wild, and let me now your thoughts on this matter.


Looking forward to your responses!


Warm Regards to All,

Brad Chubb



Be careful optimizing thrust. The best static thrust is not the best prop pitch for an
airplane.  Here are some prop dyno ideas.



Airplanes fly on HP.


 HP = Torque  X RPM / 5252


If you measure the torque and of course the RPM you know the HP.


An aircraft engine will increase the RPM until the prop torque requirements are met.


Paul Lamar



Please note that almost every item mentioned is on the dyno Steve and Everett built. One other thing to mention is the flow straightening fins behind the prop. They found that the torque readings were being effected by prop swirl until they put them on. Only important if you are interested in very accurate HP readings. Most of the time relative readings are good enough. Get your baseline and you can tell if what you did helped or hurt your performance. For someone looking to build a dyno I would suggest looking for a used airboat prop in good shape if testing for high power. They are usually designed for large V8 power and will work for 200+ HP

Bill Jepson


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