Stuart wrote that pistons have been shipped from PE to me via FEDEX.  I checked the tracking number supplied.  They are enroute across the Pacific and should arrive May 19. 

 

He also requested that I send my cylinders to PE for repair.  When I responded that I had already shipped cylinders to ECI for repair, he asked for a copy of the ECI invoice to pay from.  I responded with the quotation from ECI.  The cylinders are currently winging their way to ECI in Texas.

 

We are heading in the right direction.

 

As to the question about oil analysis and pistons: I have not done oil analysis.  I am not sure it is a readily available option here in Australia, and years of oil analysis on my TR-182 failed to provide much useful information since virtually all problems that occurred over a 2000 hour TBO run were at the top end (exhaust valves, exhaust manifolds, turbos).  Oil analysis gave no indication of these problems which surfaced at annual inspections.

 

I did pull and disassemble the oil filters on my Lancair IO-550.  First oil filter was pulled at 25 hours after the mineral oil run.  Most of what appeared on the paper and appeared to be shiny metal was in fact shiny carbon bits, and the small amounts of metal (probably aluminum) found using jeweller’s glasses was within guidelines for first run engines.  (Lycoming has an excellent technical paper on what to look for and how to interpret oil filter debris.)  There was no magnetic material present.  The second oil filter was pulled at 67 hours and had virtually no metal visible to the eye aided with four power jeweller’s glasses and a 500 watt light.  I put the filter elements in plastic baggies and marked them so I can compare with others in the future.

 

While the pistons had suffered various degrees of scuffing and the cylinder Cerma-Nil plating was visually scored (not deep enough to feel), the piston rings all looked pristine and seemed to take it all in stride.  The new piston rings used in the Cerma-Nil cylinders are moly coated and apparently quite tough and wear resistant.  They appeared barely broken in and had a nice polished appearance on wear surfaces.  However, the compression ring groove width clearance was found to be 0.009 on all pistons.  .  The groove clearance spec is 0.0015 to 0.004.  Therein lay the source of the ring flutter problem. 

 

The pistons were remarkably consistent.  Ring end gap clearances were right on the money with the second ring end gap about 25% greater than the compression ring gap, as per current recommended practices.  It was the piston to cylinder bore clearance that was insufficient for the forged pistons.

 

 

Fred Moreno