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EA-81 Oil Bucket?
Posted 11 November 2006 - 02:55 PM
Hi All, I have an EA-81 in my aircraft with a dry sump, and it is using oil at 1 Ltr per hour!
The compressions are all on or around 160 and it was reboared 40 hours ago with new pistons and the heads re done etc.
We fitted new valve oil seals but it still drinks oil!
Any help or advice would be greatly received.
There are no oil leaks that are visible but there is oil like residue on the bottom of the aircraft where the exhaust exits.
Posted 11 November 2006 - 03:06 PM
Posted 11 November 2006 - 03:27 PM
The engine runs great, it just drinks oil and I was hopeing someone would know of a reason.
Could the oil rings be wrongly fitted?
Posted 11 November 2006 - 06:52 PM
Posted 12 November 2006 - 04:52 AM
I yhink it breaths through the seperate oil tank?
The engine is completely dry and runs stong, it just blows a puff of white smoke when you rev it from tickover.
Posted 14 November 2006 - 11:49 AM
i'd do a leak down test next.
were the block and heads known to be good when you got them?
Posted 14 November 2006 - 02:26 PM
Its realy bugging me now as I dont understand how I get good compressions on all pots (160) and Its not smoking, have replaced valve oil seals on all four, but the oil usage this weekend was still 1 ltr per hour?
I was hopeing I had missed something basic and you clever guys could point out my mistakes.
Posted 14 November 2006 - 03:16 PM
removing the venting, PCV stuff may pose issues that i'm not aware of.
Posted 14 November 2006 - 03:37 PM
I am guessing that you are pushing oil out a breather or out a seal, and any burned oil is relatively minor. The puff on throttle-up following tickover indicates valve seals, unless the smoke continues during the throttle up period. (A little hard to tell while "driving"...)
If you used chrome-faced rings, it could take 500-1000 miles (100-200 hours???) to fully seat, assuming that the cylinders were honed for chrome faces (rougher finish).
Anyways, I would inspect the breather system, and, cowling permitting, check seal areas for blown seals (caused by improper seal-fitment or excessive case pressure due to breather issues).
Posted 14 November 2006 - 04:02 PM
The plugs look great! Not oily at all.
Yes wish I was good enough to scywrite.
Maybe it needs running in? but when its using this amount of oil its a bit scary up there!
A freind flew behind me this weekend and could not see any smoke at all?
As I said the engine runs real strong.
Posted 14 November 2006 - 05:04 PM
Posted 14 November 2006 - 05:08 PM
The only sign of oil is on the underside of the aircraft in line with the exhaust outlet.
I am begining to think it must be rings even though they were replaced with the pistons (+.020) 40 hours ago.
Posted 14 November 2006 - 06:25 PM
I am still thinking oil tank/case breather system. Where does the tank vent? possibly near the exhaust stack? Is there any sort of "road draft tube" that vents either the case itself or the tank system? What does the oily residue on the plane's underside look like? Relatively clean oil or sooty residue? (Probably not easy to tell on an airframe...)
Posted 14 November 2006 - 08:12 PM
Posted 14 November 2006 - 08:34 PM
Posted 14 November 2006 - 08:54 PM
Posted 14 November 2006 - 11:58 PM
use a UV dye to find the leak
Posted 15 November 2006 - 12:45 AM
I backup the oil ring presumption. But I would have no idea how to fix it without changing them (again) which I know would p*** me right off.
Although, I would of thought a litre an hour would be very visible in the exhuast smoke..
Posted 15 November 2006 - 04:29 AM
The engine was standing (well preserved for 12 months) and I replaced the seals before fitting and constantly check for leaks= none.
The oil is held in a tank and pulled into the sump.It vents into the top of the oil tank and there is a overflow tank that then vents to the outside.
The residue underneath is a black smoky oily film all over the fibreglass undersideof the aircraft.
As I have said there is no visible smoke apart from first rev from tickover and then it is just a puff of smoke, and the plugs are dry and good colour.
Yes I agree the oil consumption tells me something is wrong and I think It is approaching a strip down. I have spoken to Ron at Ram engines and he can supply pistons and rings to fit so I really am stuck as to what to do at present?
Posted 15 November 2006 - 06:40 AM
eg; after the combustion chamber but before the exhaust
im not really 100% into how these engines work... just throwing possibilities at you
Posted 15 November 2006 - 12:40 PM
Posted 19 November 2006 - 11:47 AM
Posted 20 November 2006 - 11:30 AM
Posted 02 December 2006 - 07:57 AM
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