Has any one done in depth monitoring of combustion engines using Vibration analysis ?

What are the combustion engines used for? Is it for continous or emergency/standby power generation?

Have you considered oil tests?

Josh, Firewater pumps, again

We Have a Emergency Diesel Pump at our facility. We do NOT monitor the vibration on the engine. We DO monitor the vibration on the pump and bearings that are driven by the engine. What we do for the engine is monitor and service the starting batteries every 30 days, Keep the engine oil at operating temperature constantly through the use of block heaters. We monitor fuel pressure and cleanliness. Every 30 days we run the engine under load. We change the Oil & Filters Yearly. We drain & flush the cooling system at least once per year.

Do you do oil & coolant analysis?

Perhaps we don't need VA for diesel engines used for emergency and standby purposes but if they are used for continous industrial power generation, maybe we need to do so?

U.S. Navy, Coast Guard and Power industry have used Diesel Engine Signature Analysis with success for some years now.
This is better for engine that accumulate a lot of operating hours.

For infrequently used engines, I would capture compression amd firing pressures and exhaust temperatures as well as coolant and oil analysis on a quarterly basis.

CAT also has a PAR (Performance Analysis Report) system for their engines where you can either use hteir tech to perfomr the test or possibly send your tech to their school to get certified. I'd just use their tech, they have the experience

Another link is ot Seaworthy Systems engine analyzer.

http://www.seaworthysystems.com/industrial_internet/icon/

MPR DESA

http://www.mpr.com/news/profile/pf9_cbm.html

There are some diagnostics tools specially designed for reciprocating equipment, like Windrock or Dynalco products. However, they are expensive and not always is possible to apply them to medium or small engines (crosstalk). Maybe you can explore some external service support with tools like these, if your reciprocating engine is too big to justify the diagnostics.

At the other hand, if you don´t have this option I recommend you to monitor with your FFT analyzer, the cilinder heads, the main bearings, frame support and output bearing. Take special attention to overall changes and specially to time waveform impacts (this could be difficult becasuse is not phased vibration, but some data is better than nothing).

There is an ISO standard that describes specifically what points you should set up on a reciprocating engine, but I don´t remember exactly the name. Maybe some other guy in this forum could give us a lead. Take vibration readings in velocity and acceleration, not tried enveloping or peakvue on these ones, but could work.