0-360 using oil

[John j]

Hello everybody I am having a really tough time with a lycoming 360 using oil. The story makes no sense to me or local engine shop. Engine has 500 hrs rebuilt 2 years ago by me used new crank,cam case sent out all part reconditioned by reputable shops. I used new ECI cylinders can't get this piece of @$#% to quit using oil!! use a 1 qt in 4 hours like clock work. I have had cylinders rehoned twice with zero change have tried phillips xc 20-50 oil first attempt used phillips strait mineral oil on second attempt made no difference. I ran engine just like ECI said in there literature can't get it to stop drinking oil. I removed cylinders for the 3 time sent them back to ECI they said cylinders were fine nothing wrong!! only problem with that theory cylinders are burning oil for some reason must be problem with cylinder right?? I have been told by a few local shops ECI sucks throw them away use lycoming that a expenisve fix that may or may not work. fundamentaly cylinders are the same I dont sees why one would work and one wouldn't ??. I added air oil separator trying to mask problem didn't help throws zero oil out breather so its obviously burning oil. I am flying pa-12 with 82-42 fixed pitch prop thanks for any ideas i really don't know what else to try thanks!!

FYI they are steel cylinders

[skyfixer8]

What condition are the spark plugs in as far as oily deposits, is there any oily residue in the exhaust system at the stacks for the cylinders? What kind of compression readings do you get on a compression test ?
Also, if you only use 1 qt of oil in 4 hours, that is about average use according to everything I have read in Lycoming manuals. also, I have had no problems with ECI cylinders.

[John j]

I Showed plugs to local engine shop they thought plugs looked like they were burning oil. There was no oil in exhaust, there was a little oil in one intake tube. I removed Oil sump had it leak checked it was ok the valve guides checked out ok no good answer on where oil inside intake tube came from. Compression has always been low 70s. 1 qt in four is within lycoming tolerances it more than it should use even ECI said that was to much oil burn. Should be around 8 hours to 1 qt or better. thanks for any ideas!!

[vaflier]

Pistons are not undersized by chance ????. Incorrect rings ???? Ring end gap way to wide ???? Valve guides ok ??? Cylinders not oversize with standard pistons in them ???? Pull the cylinders and inspect and measure everything, bet you find the problem.

[John j]

Have had two different local shops go through them when I rehoned first 2 times. I sent them back to ECI to make sure we were not missing something. They said they checked out fine nothing wrong with them?? Theres something wrong somewhere if its using that much oil and it has to be in top end?? as I have been told numerous times but what?? if the cylinders check out ok according to ECI what I should try next. Thanks in advance for advice

[vaflier]

How much oil are you putting in the engine. On mine if I fill it to 8 quarts it will blow one out in 3 to 4 hours. If I only fill to 7 quarts it will go about 20 hours before I need to add one.

[John j]

usually add 6 qts run it down to 5 then add one sometimes start with 7 run to 5. I have checked dipstick as well to make sure its actually 6 qts

[vaflier]

Can you tell from the plugs or the exhaust which cylinder is using the oil ??. Are you sure you have no leaks. I would look really hard at the one that had oil in the intake tube. No chance rings are chrome ???. The pics of the plugs look to have a tan color to them which would be good, it is a little hard to tell. If black then definitely oil on them. Also look at the fuel pump vent tube. Is it blocked in any way. It might be possible for it suck engine oil into the fuel system if it is. Not very likely but conceivable. It would most likely allow fuel into the base and thin the oil which could result in increased consumption. It could also allow oil to be vented overboard if the pump is bad. Just thinking about possibilities. It has to be going somewhere.

[skyfixer8]

You noted you had oil in one intake tube, aside from all the re-honing done, has anyone looked at valve guides and valve stems for proper dimensions, also what do faces and seats look like, and leakage past them ? Also, VAFLYER makes a good point on what rings are installed in the cylinders and are they facing in right direction (yes, they can be installed upside down). One other point, looking at pictures of spark plugs, those would be replaced in my shop. Looking at electrode wear and rust (?) on the barrels. How long have they been in service ? Gap looks pretty excessive, but might be close up distorting the gaps.

[John j]

The plugs are definantly at the end of their life will replace. Cylinders have been checked and everything is within tolerances. I have been using a borer prop 82-42 paddle prop that approved on the 180 hp pa-12 only thing I can try is a cruise prop try and load the engine better and push rings into cylinder walls. What prop would be a good cruise prop that would fit 0-360 thanks