Peter wrote:
I think MEK is banned here…
Widely available on eBay UK. Nasty stuff in my view.
I am mildly sceptical about the likely efficacy of the technique, but happy to be proven wrong.
It has always surprised me that people claim good results washing their fuel injectors in MEK, when the said injectors get a really good solvent (avgas) pumped through them at high pressure the whole time 
But cylinder glazing is probably hard stuff, because the standard solution (no pun intended) is a re-hone. If it could be simply dissolved, people would do that instead of re-honing. OTOH if the rings are damaged and need replacing then you need to re-hone the cylinder anyway.
Ive done the flush once and it freed up crude from an exhaust valve which was down to 52/80. Right after the flush it was back up to 60/80 with no leaking sound into the exhaust as before. The oil consumption improved by 1.5 hrs. So while there was not a great improvement in the oil consumption, it did improve and it helped with the valve seating as well. Flying with a leaking exhaust valve to burn off the deposits is a gamble because you might just be burning the valve. Why not do the flush and possibly get a better seal?
My brother had it done to his car engine which was burning a lot of oil. He claims it solved his problem. Don’t know what solvent was used.
Peter I am struggling to see what the problem is with your engine. You had one high oil consumption flight that could have been measurement error?
Jason – see previous posts. There has been a change during 2015, around the middle. Then it got really bad on the Corsica-UK flight.
The data was confirmed on the first local flight after that. This is the data including that one (in quarts/hour)
All these flights were local, low level, high power. I need to do more, with one at normal power (65%) and one at FL100, before knowing whether it’s OK to do a long trip. And that assumes good wx. I don’t know what FL150-200 would do. Another pilot who had a very similar issue told me it took 20hrs to clear.
I own a garage and am not an advocate of engine flush. I tried it once and the dislodged sludge blocked the oil feed to the cams. Two failed cams was an expensive lesson.
C210_Flyer wrote:
Ive done the flush once and it freed up crude from an exhaust valve which was down to 52/80. Right after the flush it was back up to 60/80 with no leaking sound into the exhaust as before.
There is another [simple] way to seal-up lead fouled valve seat: do a valve lap without pulling the jug as Paul New describes in this article. I have used this technique with excellent results. TAS valve lapping
That said, the OP is concerned about rings – not valves.
I don’t have bunged-up or leaky valves. Borescope showed them to be perfect, compression is good too. 75/80 mostly.
Would I be right in that if the front crankshaft seal was leaking, there would be visible oil inside the bottom cowling?
Peter wrote:
Would I be right in that if the front crankshaft seal was leaking, there would be visible oil inside the bottom cowling?
Well yeah, where’s it going to go ?
Leaks are very messy, a .5 qt/hour leak would have oil streaming all over the inside AND outside of the engine cowl !
