Oil Reports - Blackstone

[GraemeSmith]

Any interest in sharing oil reports on the AeroVee? For comparison and sensing where our engines might be headed.

I'll go first with the following observations:

My engine has a 60 micron Petersen Racing cleanable filter and I took the oil screen out the sump. The way it is plumbed - the chunks should make it to the removable filter - so leaving the screen in place - just adds to work at an oil change. I made up for the the rim of the screen by adding gaskets to the sump cover - though I don't think this is strictly necessary.

At oil change I run engine to warm oil well, stop engine, lift tail so the sump is truly the low point of the engine, at the sump cover plate I've fitted a quick drain fitting (with safety cap) so once the oil is hot - I can hook up the oil vacuum pump and suck the oil out the engine - which keeps mess to a minimum. Once the oil is all out - I shake the vacuum container to mix the oil well and then sample it for the Blackstone sample bottle. Then I hook up the vacuum one last time and drop a couple of capfuls of mineral spirit into the oil fill and verify it is vacuumed out - which means I have as much of the oil as I can get. I break the Petersen filter and inspect the element, clean it and replace it. Service with oil, run up and leak check.

So - so far 3 changes in and beginning to get a feel for the trends. Iron and Magnesium are running a bit high - though by this third report - with no trend so we are currently putting this down to sustained use and perhaps my habit of mixing the oil well before sampling instead of taking some "mid stream" - which is hard to do with the vacuum hooked up. The "Universal Averages" on the right column are the other AeroVee's that are sampled by Blackstone - and averaged. So you get a sense of your oil against the "fleet". But they are cautious about this as their "fleet" sample is small and statistically hard to say there is a real "average" which most fit.

I think MOST of my make up oil is due to slinging oil with aerobatics - even with the oil separator installed and returning oil to the sump. I do have a streak on the hull after acro.

The debris from the filter - that I sent with this sample - and which Blackstone thought might be some kind of sealer. I then went "Duh" as I realized I used Brown Permatex gasket sealer on the cork rocker covers that oil change and this is almost certainly what I sent them. I'm not too worried about that debris at this time.

[mike.smith]

I'm going to say things that are probably obvious to seasoned aircraft owners, but I'll say them anyway.

My analysis is done by Lab One Aviation. The elements tested for are fewer than those in the Blackstone report. Probably why the Lab One testing is cheaper. I see Iron, Chromium, Copper, Tin, Aluminum, Nickel, Silver, Silicon, Phosphorus, Molybdenum, Titanium.

I'm not a chemist, but I'll bet differences in testing technology used by different companies will yield different relative numbers. So comparing numbers between different testing services may not mean much.

As someone whose early oil analysis trends revealed my nickasil cylinders going bad (nickel and aluminum took obvious turns upward), and who now has 6 years of oil analysis on the same engine, I can state two things I believe are truisms. 1. Looking at individual numbers is nearly meaningless, and only serves to get your undies in a bunch for no reason. Lighten up, Francis... 2. What you're looking for is TRENDS. So unless you see some obvious out of place big honking number, just watch the trends between oil changes. If you seen something moving constantly upward, now you have something you can hang your hat on and look for the culprit.

Incidentally I don't believe there is any reason to use any kind of sealant on the cork gaskets for the rocker covers. The cork IS the seal. Sealant just makes removing and replacing the gaskets that much more difficult. I've never used sealant and never had a leak. My two cents.

[GraemeSmith]

Incidentally I don't believe there is any reason to use any kind of sealant on the cork gaskets for the rocker covers.

And ordinarily - I would completely agree. The original builder had a lot of trouble getting the rocker covers to seal. Been through (and supplied with sale) a mound of cork gaskets and was trying silicone gaskets. Despite correct torquing - the covers were oozing on the bottom aft corners.

I believe in this case the real issue is the rocker covers can't quite get seated correctly because the baffling is JUST interfering enough and the rims of the rocker covers are torquing against the baffles - not the cylinder heads. Next month when I can swing some hangar time in the AP's shop while doing the condition inspection - I have this issue down to revisit. I think the baffles need some careful adjusting. But the windy tie downs are not the place to be doing it! In the meantime sealer (yes a PIA to clean up) is stopping the ooze.

[mike.smith]

I have found that the stock rocker cover bolts are a bit too long, and bottom out before the cover/cork can fully compress. You might try a slightly shorter set of bolts. There's a lot more pressure exerted from the bolts than from the baffles, so I'm not convinced the baffles are the culprit.

[GraemeSmith]

I have found that the stock rocker cover bolts are a bit too long, and bottom out before the cover/cork can fully compress. You might try a slightly shorter set of bolts. There's a lot more pressure exerted from the bolts than from the baffles, so I'm not convinced the baffles are the culprit.

Will check that out too - thanks

[Area 51%]

I've tried two different sets of cast valve covers on my VW car. They both leaked/seeped. Put stamped steel units from CB Performance on.....not a drop. I suspect the steel covers have an ability to twist/give a little to aid in the sealing process that the cast covers lack. Or the aluminum covers are simply the best the Chinese can produce. I have a set of CBs resting comfortably on our Aerovee.

As far as sealant goes, I use a product called Gasgacinch. It acts like contact cement, meaning you put a thin coat on both surfaces, wait for it to dry, then assemble the components. If you get the placement wrong, you get to try the whole process over again. The good news is Gasgacinch can easily be removed with lacquer thinner. Even when it's dry. I use it to hold the gaskets in place on the cover. I only apply it to an inch or two in the center between the gasket and cover to keep the gaskets from sagging out of place during assembly.