Ryan Stark | Blackstone Laboratories

About Ryan Stark

Ryan started at Blackstone in 1997 after graduating from Purdue University with a degree in mechanical engineering. Ryan is responsible for writing and maintaining Blackstone's software program, setting up and managing the lab, writing reports, and a million other things that need to be done in a business. When he's not kicking ass in the lab or writing code, Ryan enjoys putting his pilot's license to good use, working on his '84 Chevy 3/4 ton, and raising his kids. As an experiment, Ryan ran Aeroshell W65 — an oil with no zinc or phosphorus in it — in his Chevy to determine if the hype over ZDDP (zinc dithiophosphate) is all that or not, figuring if the experiment ruined his engine, well, he's rebuilt it before. (Spoiler alert: The engine was fine. To read about the endeavor and see pictures from the rebuild, read the article "Rebuilding a GM 350 Engine.")

The eBay Oils (Part 2)

Welcome back to the eBay oils! If you missed the first installment of this article, you can read it here.

True to his word, Ryan listened to his Passat (if you’ll recall, it was making a noise that sounded like “Sell Me” in German) and got his wife a new Hyundai Elantra this month. Free oil changes were not included as part of the deal, so Ryan will be changing his Elantra’s oil himself. And while he’s willing to experiment with his 1984 ½ ton Chevy pickup truck, it’s doubtful (for now, at least), that he’ll be using either Wolf’s Head or Fox Head oil in his new car.

Wolf’s Head SD 10W/40

Wolf’s Head Motor Oil Company was originally founded in Pennsylvania in 1879 as “Pennsylvania Crude.” (The source of this is Wikipedia, so take this information with a grain of salt.) I’d place the can from the late-1970s or early 1980s. It is “Formulated from Finest Quality Base Stocks and Superior Motor Oil Additives” and back then, like today, the container gives no actual clue as to what the additives are. That’s where we come in. The report is an interesting one. Note the lack of calcium, which is used in almost all engine oils nowadays as a detergent/dispersant additive. Instead of calcium, it contains a lot of copper as an additive. This is a trend we were glad to see die. All that copper in the oil masks bronze wear.

Wolf’s Head ATF

Wolf’s Head also made (makes?) an ATF, though the only selling point on this can is that it’s “Refinery Sealed.” Maybe they couldn’t think of anything interesting to say about it, because honestly it looks just like a lot of ATFs we see today: mostly phosphorus and zinc, with a smattering of other additives thrown in for good measure.

Fox Head 40W

Oil marketing has come a long way since the days of yore. Today when you want to buy a high-dollar oil you’ll find it has a name that conjures up something special: speed (Red Line), richness (Royal Purple), slickness (Amsoil), racing (Mobil 1), space-age (Quantum Blue), etc. I’m not sure what “Elf” is meant to conjure up, but they follow it up with “Excellium” so you know it’s Excellent oil. Contrast those names with our next contender, Fox Head, which just makes me think of…well, a fox head. In my oil. Fortunately, that’s not what analysis turned up. (Although…we don’t test specifically for fox heads, so we could be missing something here.) The Fox Head can is red, white, and blue, so you can feel patriotic when you buy it (unless you’re in Canada. Then you can indulge in justified rage about Americans and how we think we’re the center of the world). Fox Head oil was made by the Tritex Petroleum company out of Brooklyn, NY, and my extensive research (aka first-page Google results) tells me the company still exists and is presently located in Tulsa, Oklahoma. The logo, a sly-looking fox, has nothing on today’s slick oil packages. And the oil itself also has nothing on today’s oils: the oil itself is nearly bereft of additives. Basically a mineral oil, it has a little magnesium, phosphorus, and zinc in it, and not a lot else (Figure 3). This is not necessarily a problem, however. As you’ll recall in the article when Ryan used 30W aircraft oil in his truck, wear went up a little but the engine didn’t fail or anything. Still, I won’t be putting it in my Outback anytime soon.

Shell Rotella S 10W

Shell Rotella has been around for a long time. It’s good oil, and since they’ve been making it for decades, they’ve pretty much got the routine down and haven’t messed with it a lot over the years. Unlike now, when you can actually follow Shell Rotella on Twitter (who knew Rotella had so much to say?), back in the day Rotella had to get by just by on traditional advertising and word of mouth. We called Shell to see how long they’ve been making this oil and the guy not only could not tell me, but he was unable to tell me who might know. Surely someone at that company has a historical file? If so, they’re not sharing that info with plebeians like us. He did mention that Rotella really made its name in the ’70s, though I’m guessing this can of SF, SE, SC oil was made in the late ’80s. He also said the “S” versions of Rotella were sold internationally, and indeed, this can came from our friendly neighbors to the north (*waves hi to Canada). Suffice it to say that the oil has changed very little over the years. Its main additives are the same as what we see today, but the interesting part of this oil is that it’s a 10W (Figure 4). We often see heavy-duty thin-grade additive packages in tractor-hydraulic fluids, which are used in systems like transmissions and hydraulic systems in off-highway equipment like bulldozers and backhoes. Note the TBN of this oil read higher than most of the others we’re talking about. That’s because of the high calcium level¾the TBN is based on the level of calcium sulfinate and/or magnesium sulfinate. When those compounds aren’t present, you get a low TBN.

Quaker State 30W & 10W

Next up is another oil familiar to today’s buyers: Quaker State. This HDX oil is a straight 30W, and Quaker State was ahead of the marketing game on this one. The can’s copy touts their “high quality,” “modern refineries,” and “quality control laboratories,” and this was about as scientific as it got 30 or 40 years ago. The additive package is fairly stout, though like Wolf’s Head oil, calcium is in short supply (Figure 5). We also bought a can of Quaker State 10W oil, and when we looked at the report we had to go back and double-check the can to make sure this wasn’t actually ATF. It’s not: it’s labeled as an SAE 10W oil, though the additive package looks an awful lot like what we see of out today’s transmission oil. Interestingly, there’s a lot of barium in it (Figure 6). Barium must be expensive, or else it doesn’t do much, because we rarely see it in oil samples of any type nowadays. This is engine oil, but it might work in transmissions too.

Quaker State Deluxe 10W/40 & Sterling 10W/40

Apparently we are fans of Quaker State, because we also tested a couple more varieties: Quaker State Deluxe, and Quaker State Sterling. As you know, modern oil companies generally have a lot of different brands under the same name (for example, Valvoline has TK, TK, and TK, as well as TK). For the most part, these oils are mostly the same; they’ll throw in a few slight differences in additives and call it good. These cans of Quaker State, however, were mostly pretty different. The Deluxe version looked a lot like their 30W oil (but more calcium–Figure 7). Quaker State Sterling HD 10W/40, on the other hand, went out on a limb with almost 800 ppm sodium, almost no magnesium, and then levels of calcium, phosphorus, and zinc that are comparable with today’s oils. Touted as “Energy Saving Motor Oil,” Quaker State was getting its game on in pushing this brand: it mentions “special friction modifying additives,” the longevity of the company (over 60 years when the can was made), and its suitability for those wishing to follow extended drain intervals. Heck, I’m sold, and I see this stuff all the time.

Mobil Special 10W/30 & Artic 20-20W

Mobil is no slouch in the marketing department, but they really outdid themselves with the can we tested, “Mobil Special.” The name alone tells you all you need to know about why to buy this oil. All oil companies like to mess with their additive packages, and Mobil, like the others, changes their oil up fairly frequently. That was the case back in the day too, because the additive package in this “Special” oil is different from what we typically see in today’s oil. Apparently Mobil was an early rider on the ZDDP train, because this oil is chock-full of both phosphorus and zinc. Calcium and magnesium are present too, but at lower levels (Figure 8). We also tested a sample of Mobil Artic oil. The Artic can is clearly older than the other Mobil can¾the logo is older, and there’s no zip code listed with the address, so it’s pre-1963. A straight 20W, it’s labeled as HD oil, meeting “Car Builders’ Most Severe Service Tests.” While it’s “Artic” and not “Arctic,” we can’t help thinking this oil is meant for cold-weather operation. The can even looks like it’s ready for winter: all white, but with a little color on it so you don’t lose it in the snow when you’re out in the tundra changing your oil. This one definitely has an unusual additive package, relying heavily on barium (maybe it’s got a purpose after all!). Interestingly, less zinc is present than phosphorus (Figure 9). Nowadays it’s the other way around.

Phillips 66 Trop-Artic 10W/40

We were going to stop with Mobil Artic, but we can’t resist comparing that one with Phillips Trop-Artic. We’re not exactly sure what Trop-Artic means, but since the can is selling itself as All-Season we’re guessing it’s something along the lines of “use it in the tropics, use it in the arctic.” A 10W/40 in viscosity, this oil looks a lot like what we see out of modern 15W/40s¾a stout additive package and a relatively thick viscosity (Figure 10). In other words, even though this oil is several decades old, it would be fine to use in your F150 tomorrow.

Okay, ten old oils is all we can do for this article. Fortunately the next installment will contain such gems as old versions of Amsoil, Castro, Sinclair, Amoco, Lucky Strike, Union 76, and more! Tune in next time for the next installment of the eBay oils!

By Ryan Stark|2024-09-19T10:11:13-04:002023|Articles, Gas/Diesel Engine, Marine|Comments Off

The eBay Oils (Part 1)

We were visiting my in–laws last November and needed some oil for my Passat. It just starting to clatter a little on start up and when I checked the oil, it was down two quarts. The clatter sounded something like “Sell Me” in German.

Anyway, while searching for some make up oil (my father-in-law Lee had two quarts of my favorite—Super Tech), I came across an old can of Pennzoil ATF. By old I mean it was a round can made of cardboard, like a Crisco can. It brought back memories of helping my Dad change oil when I was seven or eight. (My job was jabbing the pour spout into the top of the can.)

Lee said he bought it for an old 1984 Buick LeSabre. That was the last car he owned that leaked oil and when that car was gone, he was left with half a can of ATF. Working in an oil lab, I was intrigued by what was in it. So Lee let me have the quart because he would never need it again.

When I got back home, I started looking at old cans of oil on eBay and found a lot. It turns out these are fairly collectable, and I found roughly 300 unopened cans for sale, of all different types and years. I decided that in the interest of science, Blackstone should buy some of these and test them to see what was in them.

Now, you may think I’m crazy because once you open an old can of oil like that you ruin the value of it, but I was prepared to make this sacrifice for the good of the oil analysis community, and plus, Blackstone was buying, so it really didn’t bother me too much. If you think about it, how lucky can you get to be able to buy little time capsules of a product and test it? Can you by beer from 30 years ago and still drink it? I guess, but chances are it’s long gone bad. How about a 30-year-old can of sardines, or a 5-year-old one for that matter? No way. So, I would really be a fool not to try this and see what shows up.

One thing led to another and before I knew it I had bought 28 cans of old oil and spent almost $1,000. Pretty soon these oils started rolling in and I experienced a little buyers remorse. Did I really need to buy all this? What was I going to do with the cans? Once you open a can of oil, it’s almost impossible to seal up properly. Would there be anything to even see in these samples? And, does oil go bad? We get this last question all the time, and my answer has always been no, but I was dealing with oils from the 1930s,1940s, and 1950s here–really old stuff. Maybe all the additive in there (if any was even used) would settle out and there wouldn’t be anything for us to read. Fortunately, I had bought some oil that would help answer that.

Shaken, not stirred

Before I did any testing, I wanted to see if I would need to shake these oils up. If the additive had fallen out of suspension, then all of these old cans would need to be shaken before I even opened them. Ideally, it would be great to have two oils of the same batch, so I could run one unshaken and run one shaken and see what type of difference shows up. That’s where my two antique vintage Havoline Texaco all-metal cans came into play. “SAE 20-20W” is stamped on the top of the can, and the text on the back says, “For API engine service classifications MM, MS, DG, and DM.” It also assured me that it’s “The finest engine protection in the world.”

I bought these two for $25.00 total, and going by what looks like a date on the can, I think they were from 1968. They were from the same seller and looked exactly the same. Chances are good they came from the same case someone bought years ago and they have been sitting on the shelf even since.

I decided to run a test. I would take one to the local hardware store (www.doitbest.com) and have them put it in the paint shaker for five minutes. Then I would crack them both open, test them, and see what differences showed up. You can see the results in Hav No Shake and Hav Shake.

To my surprise, there was actually more of some additive in the oil that I didn’t have shaken. Also, the additives really weren’t that different from what we see in today’s oil. The oil was supposed to be a straight 20W and it was. Also, it had a strong TBN, so the additive that was present was still active.

About the only unusual thing was that phosphorus was higher than zinc. Those two elements are normally from the ZDDP additive, but maybe there were using a different formula back in 1968. It’s hard to say, but from that test I learned that when it’s done right, the additives actually become part of the oil during blending and time/gravity alone won’t cause them to separate back out.

So that settled it. I didn’t need to shake all of these oils and could just start running them. That’s good because some of these old cans were bound to break open during shaking and spray oil all over Norm and his paint department.

But is it still good?

However, that really didn’t get down to answering the question: Is this oil still good to use? For that, I was going to have to run another test.

Of all the oils I bought, one of the most expensive was very rare—according to the seller, antique Renuzit Certified, Premium Quality 2500 Mile oil. Not only does this oil offer the ability to run the oil 2500 miles in between oil changes (“Cut your oil bills in half!”), but it claims to provide a longer engine life, smoother motor, stronger oil film, and best of all, “a faster getaway.” They don’t actually advertise it as the best oil for bank robbers, but they should have.

It cost $75.00 + $25.00 shipping, but I got a whole gallon of it. Unfortunately, the can had some rust on the bottom of it and it started leaking during shipping. The good news was, I now needed to do something with this oil and I wasn’t going to dump it in a waste barrel. So I am going to actually run this in my engine. Not in my Mini (it’s still under warranty), but my trusty old GM 350, rebuilt twice by yours truly.

I know what you are thinking—this SOB is out of his mind!—but don’t try to talk me out of it. I’m going to run this oil and decide once and for all if running old oil really hurts anything. Will my engine blow-by and leave me stranded on the side of the road? Will the seals start leaking like mad a leave a slick of oil behind for other cars to slip on and spin off into the ditch (a la Spy Hunter)? Will this be the end of my beloved 1984 Chevy Custom Deluxe? Well, like the monkey said after he shit in the corner—that remains to be seen!*

Castrol with Tungsten

My first purchase was Castrol with Tungsten. Tungsten! What the hell? Since when did they start putting light bulb filaments in oil? Or maybe a better question would be, “When did they stop?” The bottle was partly in French, so I’m guessing it was from Canada, and that makes sense; the oil blenders up there will put anything in the oil and if the engine breaks, they just blame it on the cold. (Just kidding, Canadians! You know we love you guys.) I had to buy the single element standard to run Tungsten and set our spectrometer to run it, but after a little messing around, we got some results .

Sunoco DX Diamond motor oil – API SB

After seeing Castrol with Tungsten, I was ready for anything, but when I saw Sunoco’s Diamond oil, I didn’t really think they put diamonds in there. That would be one expensive additive. I did want to see what was in this SAE 40W oil though.

The case says is has an API rating of SB, which was used from 1930 to 1963. Several websites state that this oil can cause equipment harm. All I can say to that is, too bad I don’t have five quarts of this stuff, because I love a challenge. It doesn’t look so harmful in the oil analysis. The viscosity wasn’t quite in the 40W range and it didn’t have much in the way of detergent/dispersant additive present, but then again, it does state on the can that it is “Recommended for vehicles that do not require detergent oil.” Sometimes those oils don’t have any additive at all, but there was quite a bit of phosphorus and zinc here (figure 4).

K-Mart 10W/40 Motor Oil (API SE) & DEXRON ATF

Back before Wal-Mart dominated the world, there was K-mart, and when I was in 4^th grade, there was no greater crack on someone than “You buy your underwear at K-Mart.”

Well, I wonder what those boys would say if they found out I bought my oil at K-Mart too. The motor oil is listed as Deluxe and it says on the side of the can that this is specially blended multi-viscosity oil containing the finest approved additives and base oils. So you can’t go wrong there, right?

Looking at the results, I’d say this oil is indeed deluxe. The viscosity is pretty strong for a 10W/40, and the additives would be suitable for diesel use. The oil does have a CC rating as well as an SE rating, and those put the date of this oil as being made sometime in the 1970s. The ATF has a standard additive package until you get down to barium. That’s not used much anymore. See figures 5 and 6 for the analyses.

Valvoline SAE 20W – API SB

The big marketing claim for this oil says it “Contains Miracle ChemAloy.” Miracle! Really! Does the Pope know about this? There were no miracles in the additive package that I can see, but maybe that’s the miracle of it—you can’t see it, but it’s in there and it works. This oil doesn’t have much of a TBN because it doesn’t contain much calcium, but the old stand-bys of phosphorus and zinc are there, and at pretty much the same levels we see today (figure 7).

Harley-Davidson Premium Grade Motorcycle Oil (SAE 40) 75-P

This can caught my eye because it reminded me of Evel Knievel. In fact, the logo on the can is the same as what is on Evel’s website, so the two were heavily linked back in 1970s.

What’s interesting is that Harley-Davidson actually came up with their own oil weight specifications. This can is 75 Medium Heavy and is for use in all motors at temperatures above 40°F. They also made 58 Special Light, which is good for temperatures below 40°F, and 105 Regular Heavy—good for all motors operating under severe conditions at high (?) temperatures. Apparently, it was up to us to decide what high temperatures are; also, neither the 75 or 105 was “special.” I’m sure the special label added some extra cost and that made it special to Harley-Davidson.

Looking at the report, you’ll see this was a 40W oil and WOW look at the barium. That isn’t used much anymore and was likely some sort of detergent additive (figure 8).

ARCO Graphite SAE 10W/40 (API SE-CC)

After seeing the word graphite in the name, I had to check this stuff out. True to its label, there was a lot of graphite in the oil (figure 9), and if you’re the kind of person who likes clean oil on your dipstick, this wasn’t the brand for you. Graphite is known as a lubricant, but I wonder how this stuff did in engines. Looking at the report, you can see the graphite at the insoluble reading of 0.5%. That’s extremely high for virgin oil, so the stuff doesn’t stay in suspension very well. On the plus side, the can says this oil provides

Improved gasoline mileage
Reduced piston ring and cam wear
Easy low temperature starting and excellent lubrication at low and high operating temperatures

The oil is also “Patent Pending” and I’m wondering how that application is progressing down at the Patent office these days.

In Parts 2 and 3 of “The eBay Oils” we’ll be looking at old cans of Amsoil, Mobil, Valvoline, and more. Look for the next installments this summer!

By Ryan Stark|2024-09-19T10:10:17-04:002023|Articles, Gas/Diesel Engine, Marine|Comments Off

Ryan’s Cholesterol

A few years ago I went to our family doctor for a checkup. For most of my life I’d never been one for getting check-ups, but now my insurance company pays for a yearly visit, so I decided to start.

After all the basics, the doctor suggested I do a blood test, because I’m “getting old” (almost 40!?). So after fasting for 24 hours to make sure nothing I ate would skew the results, I headed to their lab to get my blood drawn.

You can imagine my dismay when the nurse called a few days later with my test results — high cholesterol! My initial reaction was shock, followed by a realization that maybe I am indeed getting older.

The nurse said my total cholesterol read 203 and that the doctor wanted me to change my diet and start taking the drug Lipitor. Again, more shock followed by a little confusion as to what exactly 203 meant, and then a wave of depression at the idea of having to take a drug for the rest of my life, along with quitting eggs, butter, and bacon. “Fortunately,” the nurse continued, they offer free Lipitor at the local supermarket pharmacy, like that was supposed to make everything all better.

After a few letting this all sink in, I decided that I was not indeed getting older. In fact, I’d wager that I was the healthiest SOB my doctor had seen all month (based on the state of the patients in her waiting room).

Looking at data

Also, given the fact that I look at data all day long, I began to wonder about the 203 reading. What’s average, what are the units on that, and what was my average cholesterol reading? Maybe I’ve always read high.

After a little more thought, I decided to just ignore my doctor and get retested to see if I can get a trend going. My thinking was, maybe high cholesterol is kind of like high iron in your oil. We normally say that just one high reading isn’t much of a concern. Maybe it was higher before but it’s headed down now, or maybe this level is just normal for you and the way you operate your engine. A trend gives you far more information that just one bad reading. We usually wouldn’t suggest any major changes after one just one high reading, so I was a little disheartened that my doctor would prescribe a lot of life-changing measures based on one test. My course of action would be to get more information about it and check back to see if the high reading was a one-time occurrence or not.

So I had my blood tested again about a month later to see if the first test was accurate. Unfortunately it was, but still, that made me feel a little better about the repeatability of the lab and that test itself.

The vitamin D cure

As luck would have it, that same month I attended a lab training session in Columbus, Ohio at Mettler Toledo (they make an awesome auto-titrator if you’re even in need).

During dinner one night with the other class attendees, we got to talking about Vitamin D and its relationship to cholesterol. My classmate was in the business of testing for Vitamin D levels in food and said that there is a direct relationship between the two. As it turns out, the more Vitamin D you get, the lower your cholesterol goes. And what’s more, Vitamin D is free to us all, being produced naturally by your skin when it’s exposed to sunlight.

This really got me thinking — my first and second blood tests were taken in during the high of winter in the Midwest. A person doesn’t get much sunlight in the winter (at least in Indiana). So maybe if I checked my cholesterol again in summer, it would improve. This started me on a quest to get my blood tested again that summer to see if I could indeed confirm that there was a relationship between Vitamin D and cholesterol.

At the start of September, I called my doctor and requested another blood test, and this time I wanted Vitamin D added as well. After a few days the nurse called with my results. It turns out my Vitamin D level was low at 30, and she wanted me to start taking a supplement to see if I can bring that up (again with the knee-jerk reaction to one reading).

“How about my total cholesterol?” I asked. “Oh, that’s fine at 156.” she stated. This was an eye-opening test because it proved that my cholesterol level did indeed change significantly and I didn’t have to change my diet or take any drugs to artificially lower it.

This also brought up a mildly chilling realization. Suppose I started taking a drug to lower my cholesterol back in February and then had it tested again in September. My cholesterol would have read lower, but everyone would have pointed to the drug as the reason and I’d be stuck taking it for life.

After-market oil additives are a parallel to this in the oil analysis world. A lot of people start to use an additive and after several years start to think it’s the reason their engine is running well. When in reality, chances are very good the engine would still be running fine had they not used the additive.

Trends are key

All of this started back in 2013 and I have accumulated a lot of data since then on my cholesterol and Vitamin D levels. Being in the lab business, I wanted more data before I made any hard and fast statements and I’m still not ready to say one way or the other that the Vitamin D and cholesterol are related. I’m not advocating that you ignore your doctor’s advice (that’s a Stark family virtue), but I am saying that as far as testing goes, it’s not very often that you need to take action just on one bad reading. Trends are important when analyzing data, so be sure to get them even if it takes a little pain.

By the way, during all of this blood testing, I found myself longing for a lab where you could walk in and easily get blood work done without a doctor’s order, one that would send you your results in a nice, easy-to-read format, with an explanation of the data in plain English.

Also, the report would show you an average so you could get an idea about how high or low a reading might be. Whoever could come up with this type of medical lab in real life would be sitting on a gold mine. Now, you may ask, “Why don’t you start one, Blackstone?” and the answer to that is easy—we’re too busy testing your oil.

_______________________

Cholesterol follow-up

Back in August 2015 I wrote about cholesterol testing and its parallels to oil analysis. I’m sure you’re all wondering how my health has been, so this is a follow up to that. In the article I stated that there appears to be a connection between Vitamin D and cholesterol and I am here to tell you that I might have been wrong.

My final blood test was on August 7, 2015 and at the time I was taking a Vitamin D supplement to see if it would lower my cholesterol. Well, the supplement worked: my Vitamin D increased to 33, which was an all-time high; however my cholesterol also increased. So barring any sort of lab error that might have occurred, I’m not sure if there is a conclusion or not.

That article received a lot of feedback and I enjoyed all of the comments from our customers, but was especially intrigued by one e-mail I received. He pointed me towards the book “The Great Cholesterol Con,” by Malcolm Kendrick, and while it wasn’t the easiest read I’ve ever come across, it did change my life.

The books states that cholesterol levels aren’t related to heart disease at all and that I should eat anything I like. Well, I’m 43 now and can make up my mind on what I do, and I have to say, I really liked the sound of that. It was the first time I had ever heard anyone say that your diet isn’t related to heart disease and he had that data in his book to back it up.

I’ll admit I never read any of the studies he talked about, though apparently they are all available on the Internet. As for what causes heart disease, well, I won’t spoil the book for you ¾ ha ha just kidding, I’ll spoil it: stress! Reduce that in your life and you’ll be better off. Who can argue with that? Plus now that I don’t have to feel bad about putting butter on my toast, my life just got less stressful.

_______________________

Yet another follow-up

A few years ago I wrote an article about how trends in blood tests were just as important as trends in oil analysis. This medical talk spurred a lot of comments and advice which I greatly appreciate, though surprisingly enough, not too many of you seemed concerned about my suicidal-scorn for statin drugs. Still, I’d like to thank all of those was responded and I’d like to pass on one bit of great advice from a doctor/pilot. His best advice for living a long healthy life: Stay off ladders.

By Ryan Stark|2024-09-19T10:15:06-04:002023|Articles, Gas/Diesel Engine, Marine|Comments Off

Aircraft Problems: Should I Be Worried?

One of the main purposes of oil analysis it to find problems that might be developing in an engine, and after doing this for a lot of years, I can say without a doubt that it works. However, some problems are more urgent than others, and part of our job is to determine if a problem is a major one or not. Most engine problems start out minor but if left unchecked can lead to major issues, which eventually result in an engine’s demise.

Minor problems

Abrasive Contamination

Dirt getting past the air filter will cause a lot of problems in an engine, and piston scuffing is the primary concern. Fortunately, most air filters do a really good job even when they are dirty. If you change your air filter on a regular basis, then this type of problem is pretty easy to avoid, but remember, it’s also important to check the whole air induction system down-stream of the air filter to make sure no cracks or other problems exist that could be letting dirt in.

Fuel dilution

This generally includes any fuel level between 1.0% and 3.0% that keeps showing up again and again. This is not a normal situation, but it doesn’t necessarily cause an engine problems in the short term. Still, since fuel is a contaminant, it will cause the oil to oxidize faster that it normally would. That typically causes problems like stuck oil control rings, which leads us to our next minor issue.

Oil Consumption

This one isn’t really a problem at low levels because all engines are designed to use some oil. What you really want to watch out for is a change in how much oil is being burned. If you always use 1 quart every 10 hours and it suddenly jumps to 1 quart every 3 hours, then you know something has changed. That’s part of the reason we ask about oil added between changes. If you’re not losing oil due to a leak, it’s either getting past the rings or the valve guides. Granted, you can buy a lot of make-up oil for the cost of a top overhaul, but there will probably come a time you’ll have to bite the bullet and fix the issue.

Corrosion

If you fly around 5 hours per month, that should keep this minor problem off you mind, though we all know that life doesn’t necessarily allow this. Still, if corrosion is minor it should easily disappear once the engine is back to flying regularly. If corrosion gets so bad that it causes pitting on the parts, that’s when the problem elevates to major status.

Major problems

Cam spalling

This one is often directly related to corrosion getting out of hand, though it can also be related to oil starvation on things like cold starts and high RMP starts. It takes time for that thick oil to get circulating through the engine and if it doesn’t get to the cam and followers fast enough, metal-to-metal contact happens. Problems of this nature won’t necessarily cause an engine to fail, but can lead to loss of some power, which might be needed to clear that 50’ obstacle at the end of the runway.

Excess Heat

This is really a pretty broad category and is often due to operational factors, though it’s almost always avoidable if you are paying attention to your cylinder head temperatures. If those are getting too hot, then maybe the cooling baffles aren’t quite working like they should. Maybe you have a crack in an air induction tube. That could allow abrasive dirt into the combustion chamber, but would also cause that one cylinder to run leaner than others (due to extra air being sucked in) and likely hotter. Excess heat causes the parts to expand more than they were designed for and that’s when wear starts getting heavy.

Stuck or Burned Valves

Abrasive contamination, fuel dilution, and oil consumption will all contribute to this type of problem. Sticking valves can be identified by things like morning sickness (not necessarily in the morning), intermittent rough running, and high mag drops (not due to a fouled spark plug). Burned valves are usually pretty easy to spot with a borescope though might not necessarily cause major operational problems until they burn to a point where compression has significantly degraded.

Detonation

This issue develops in an engine when the combustion process is not completed correctly, usually when an engine is under a heavy load and producing a lot of heat. It can easily burn a hole right through the top of a piston, resulting in all of the oil in your engine being pushed out the breather tube and oil starvation (see below). If your engine had a good muffler, you would hear a ticking or pinging noise, but since those don’t exist in general aviation, this problem can often go unnoticed without the help of oil analysis and/or engine monitor data. If this problem exists, running a richer fuel/air mixture to keep the engine cooler should help.

Instant failure

Oil starvation

Whether it’s caused by oil consumption left unchecked or severely worn bearings not letting oil get to all of the parts, this type of problem will cause an engine to fail in short order and it’s usually accompanied by the worst sound your engine can make — silence.

Spun bearings

When the babbit is worn off your bearings, either due to hard use, abrasive oil, or lack of oil, you will start to lose oil pressure. If the problem gets severe enough, the spinning shaft will actually weld to the bearing itself and spin in place. Once this happens, the engine is pretty much shot, though amazingly enough it might still run (but not for long).

Outside causes

Of course there are lots of other things that can cause instant engine death — see the first cartoon on this link for an example, or, although it’s not a plane, this picture of my flooded MINI. Unfortunately, outside factors probably take more engines down than anything else.

It’s pretty rare for engines to fail suddenly due to minor issues, so when we see something going on, that doesn’t necessarily mean you need to get out the wrenches or head straight to the engine builder and demand a repair. Usually, you’ll have some time to see if the problem persists or is getting worse. Once that has been established, then some action will likely be required to keep the engine going, but the cost should be minor compared to the hassle and expense of having to replace the whole engine. So test your oil every now and then. Chances are good your engine will look perfect, but if it doesn’t, you’re better off knowing about it sooner rather than later.

By Ryan Stark|2024-09-18T13:49:41-04:002023|Aircraft, Articles|Comments Off

How Often Should I Change My Oil?

When it comes to the questions we get here at the lab every day, right up there with “What kind of oil should I use?” is “How often should I change my oil?” Continental and Lycoming both have guidelines in place, and generally speaking it’s 50 hours for those with spin-on filters and 25 hours for engines equipped with oil screens. But as you know, way more than calendar time should go into determining how often you should be changing your oil. There’s not just one answer for everyone. The engine manufacturer’s guidelines are better than nothing, but there’s also oil analysis. Guess which method we like best for determining how often you should change the oil?

Inactivity

One of the biggest factors we use in determining how often to change your oil is how active the engine is. We used to say you need to fly ten hours a month to keep corrosion away, but a few years back we realized that people were doing fewer hours than that and still getting decent wear numbers. So we lowered our general threshold to five hours of flying a month as what we consider “active” for an aircraft engine.

The problem is, a lot of people don’t like to admit their beloved aircraft has been inactive. But it’s okay to admit it. We can almost always tell. We even have a little question on the back of the oil slip that says “Any inactivity or problems/suspicions?” Inevitably, someone will pen a big NO in that space when in reality, he or she let the plane sit for eight months, then flew it 10 hours in the span of a month. “No!” they protest. “It hasn’t been inactive! I flew 10 hours this month!”

Inactivity usually shows up as aluminum and iron, from oxides and wear at the pistons and cylinders, though other metals can show up too. Trust me, it’s okay to admit when your engine has been inactive. That’s generally an easier and more fun problem to have than a bona fide mechanical issue. When we suspect corrosion, we almost always recommend cutting back to a shorter oil change. While changing the oil more often doesn’t prevent corrosion from happening, it does allow you to 1) monitor the corrosion to make sure it’s not getting out of hand, and 2) get the metal-laden oil out of the system sooner, so not as much metal gets washed into the oil when you crank over the engine. Abrasive oil causes more wear. Even if you have to change the oil with just two or three hours on it, that’s fine. We’d much rather see that than a fill that sat a year, accumulated 20 hours, and was full of metal.

Metal

Of course, as an oil analysis lab we also look at how much metal your engine is producing. If you’ve seen our reports, you know that we keep a database of all the engines we’ve ever seen. We average their wear and then compare that to your own sample to see what’s reading high, what’s normal, and what’s better than most. We like it when you send along notes. The more you tell us about what’s been happening with the engine lately or any specific conditions that might affect the sample, the better our comments on your sample will be.

An engine that’s making more metal than average will usually need more frequent oil changes. That doesn’t fix a problem, if one exists, but it does help you to monitor it more closely and get the abrasive oil out of the system sooner rather than later.

Contaminants

The main contaminants in aircraft engine samples are fuel, water, and blow-by. Blow-by is hard to avoid ¾ all engines blow by to some extent. You want to see lead holding steady from sample to sample. If it’s increasing, we’ll often recommend shorter oil changes until you can figure out what’s going on.

Water can enter the system just from condensation in the air, though we don’t usually see more than a trace from that. And traces of moisture, while not ideal, probably aren’t going to hurt too much. They might accelerate corrosion if you’re not flying all that much, but usually a trace of moisture won’t cause too many problems. When more than a trace of water is showing up, and it’s showing up in every sample, it can be a sign of something else going on. Often, an incorrectly set-up air/oil separator will cause moisture in the oil. When we’re consistently seeing more water than normal, we’ll often recommend going to a shorter oil change.

Fuel is also a common find in aircraft samples. We recommend taking the sample hot to eliminate any normal traces of fuel and moisture, but sometimes people have to take a cold sample, which results in fuel. And that’s okay. As long as you tell us about it, we’ll take that into account when we write the comments and we probably would not recommend using a shorter oil change just for traces of fuel. You can also get fuel in the oil from excessive priming, and again, as long as it’s not showing up in every sample, this is usually something that does not affect wear and will clear up next time. If, however, we’re seeing a lot of fuel from sample to sample, it can be a sign of something else going on so we would likely recommend a shorter oil change until you can figure out what’s up.

Environment

Where you fly also affects how often you need to change your oil. Inactive engines in a dry place like Arizona can usually get away with keeping the oil in place longer than someone in Michigan or North Carolina. In fact, humidity can cause us to alter our standard less-than-5-hours-is-inactive rule. Someone in Georgia may be flying 8 to 10 hours a month and still getting signs of corrosion and need to change more often than someone with the same engine near a desert.

Acids

There’s a lot of talk out there about needing to change the oil more often due to acid build-up in the oil, and we’d say that’s a load of hogwash. In fact we did an article on that topic for our last newsletter. Basically we ran total acid tests on a whole slew of aircraft samples and only three out of 63 samples had a TAN (Total Acid Number) over 2.0. And 2.0 is still a low reading ¾ we consider anything above ~4.0 to be acidic. Never say never, but I predict pigs will be flying before we’ll tell you to change your aircraft oil because it’s getting too acidic.

What about the oil?

Notice what we have not said we take into account: the brand you’re using and whether it’s straight-weight or multi-grade oil. When Jim started this company back in 1985 he came up with a line he liked to use: Oil is oil. We still stand by that today. The oil guys would have you believe otherwise, but brand really does not seem to make a difference in how your engine wears, or how often you can change your oil.

Well, okay, if you’re using Joe Bob’s Oil that he “recycled” in the back of the hangar from emptied-out oil pans that he filtered with a piece of cheesecloth, we might say in that case brand does matter. But as long as you’re using an aircraft-certified aircraft oil, your engine probably isn’t going to care what you use. We like straight weights and we like multi-grade oils. In the end, what you use and how often you change your oil is completely your choice. We’ll give you our recommendation and you can do whatever you want with it. If you want to run longer on the oil despite having high wear, that’s totally fine. And if you have great numbers and you really like changing the oil often, we’re not going to send out the Blackstone henchmen to tell you to start running longer. Keep your own situation in mind and make your informed decision based on what’s showing up in the oil and filter/screen, what the engine monitors are telling you, and your own comfort level. It’s your airplane and your money!

By Ryan Stark|2024-09-18T14:06:58-04:002023|Aircraft, Articles|Comments Off

The Acidity Question

Every now and then you hear about oil becoming acidic and causing internal corrosion in an aircraft engine. Usually that goes along with the oil absorbing water and then forming acids, but I’ve always disagreed with this statement.

It’s a well-known fact that corrosion is a problem for a lot of aircraft engines that don’t see much use, but is it really acidic oil that’s causing the corrosion, or simply bare metal parts being exposed to the atmosphere? So I decided to run some testing to see what I could find about acidity and aircraft oils.

Now, think back to high school chemistry. Remember learning about acids and bases? Normally with something like water, you measure the pH to determine how acidic or basic a liquid might be. A pH of 7 is neutral, lower than 7 is acidic, while higher than 7 is basic.

The problem with oil is, you can’t run a pH on it directly. So instead, we have the Total Base Number (TBN) and Total Acid Number (TAN) tests.

These are fairly simple tests and the basic principle is this. After you mix a measured amount of oil with some chemicals, you can run a pH on those chemicals. But that doesn’t equate to the TBN or TAN.

To get the TBN you add acid to the chemical mixture until it reaches a pH of 4. To get the TAN, you add a base to the mixture (in this case, potassium hydroxide) until the pH reaches 10. (You might wonder why we don’t just report the pH of the chemical mixture and have that be the end of it, and the answer to that is unknown, at least to me.)

The TBN test

The TBN test is commonly done on automotive oils, but not aircraft oil. That’s because the TBN always reads 0 or close to it with aircraft oil.

Automotive oil has a lot of additive packed in there and that is what the TBN reading is based on. That additive makes the TBN increase. Oil salesmen use the TBN test to help sell their oil, with the idea being that the higher the TBN, the better the oil. But the TBN is really just a testament to how much additive the oil starts with, not necessarily how well the oil will work in any given engine.

You might wonder why aircraft oil doesn’t use the same additives? It’s because the additives used in automotive oils aren’t ashless. The additives present in all aircraft oils have to be ashless, meaning when the oil burns nothing is left. This is why it’s a bad idea to use anything other than aircraft oil in your aircraft engine.

The TAN test

The TAN test is commonly done on industrial oil like hydraulic fluid. There is a theory that when oil becomes acidic it will accelerate wear and cause all kinds of problems, but that’s just a theory — and a pretty weak one in my book.

When most people think of acid, they might think of something like acid reflux and heartburn. Or maybe sulfuric acid burning a hole in their clothes, but that gives acids a bad rap. If it weren’t for acid, your food wouldn’t get digested and we’d be without a lot of very important chemical compounds. What’s more, there is no known correlation between acidic oil and higher wear that I know of.

It is commonly talked about that water in oil will cause it to become acidic, and maybe it will if the water has something to react to. But with aircraft oil, it doesn’t. The additives present aren’t sulfur-based like they are with automotive oils, so when water gets into oil, it usually just stays there until the oil gets hot enough to cook it back out.

Testing the theory

So for this newsletter article, I decided to run some TAN tests on various aircraft oils and see what shows up. Virgin aircraft oils usually have a TAN in the range of 0.4 to 0.8. It’s important to know where the TAN starts out, so you know how acidic the oil has become after use. (You’d think that oil starts out with a TAN of 0.0, but usually it does not.)

For the used oil data, we tested the TAN on 63 random aircraft samples.

Acid Chart

The average TAN reading for those samples was 1.3. That might seem like a fairly large increase, but in the oil analysis world, 1.3 is considered a low acidity reading for any type of system. A reading of 3.0 shows some acidity and anything over 4.0 can be considered fairly acidic.

The highest TAN reading we found was 2.3, but in our testing any readings over 2.0 were rare. In fact, only three samples read higher than 2.0 and none of those had water present, but two were considered inactive. Five of the samples we tested did have a trace of water present, but their average TAN was just 1.1, so we didn’t find any correlation between water and a high TAN.

Acid Chart 2

So how about inactive engines? Two samples that were inactive did have a TAN of over 2.0, but they were the exception, not the rule. We had 11 samples in our test run that were considered inactive, but the average TAN of those was just 1.2.

Based on this testing, it doesn’t look like oil acidity is really a factor at all. Does that mean you shouldn’t worry about inactivity? No — we’ve seen too many examples of poor wear from inactive engines to say that’s not a problem. What it does mean is that in our opinion you don’t need to worry about your oil being acidic. And in life, one less thing to worry about is a good thing!

By Ryan Stark|2024-09-18T14:08:24-04:002023|Aircraft, Articles, Gas/Diesel Engine, Marine|Comments Off

Building an RV-12 (Part 3)

Since my last newsletter about building the Van’s RV-12, my wife and I have made quite a bit of progress. In fact, we’re nearly done. I believe the phrase commonly used in the homebuilt industry is “90% complete, 90% left to go.” But really, we’re getting down to the short strokes though it’s been a long process since we are mainly only able to work on it over the weekends.

Rapid progress…at first

When we started working, the plane was in a garage in Ossian, Indiana, about 15 miles south of Fort Wayne. The tail and wings were mostly done and the fuselage kit (the third of six kits total) was about one-sixth finished. After buying some videos on how to build the RV-12, we got started. I was actually blessed with a whole garage to work in (many thanks to my step-mother Kathy), and plenty of table space. We were also able to bring some parts home to work on in my basement, which was a nice help.

Progress proceeded rapidly when we started in June 2016. The side and bottom skins of the fuselage were installed that summer, and the basic fuselage structure was pretty well completed by November 2016, just in time to crack into the fourth kit, known as the finishing kit.

This name is a bit misleading because we were nowhere near finishing at this point, but that name has a better ring to it than “halfway kit,” or “other stuff you’ll need kit.” Actually, once that kit was done we were getting close to being finished, and by close, I still mean at least a year away at our pace. This kit included parts like the landing gear, canopy, cowling, and control cables.

The finishing kit

The first section of the finishing kit was wing installation, which was exciting. It’s starting to look a little more like an airplane. At that point, we didn’t have the tail on yet and that was by design. It’s a lot easier to walk around the thing without a tail in the way and it didn’t need the tail on until later, when we started stringing the controls for the rudder and horizontal stabilator. I picked up the suggestion while attending a forum at Oshkosh and also learned there that it wasn’t really necessary to complete the sections in order. Things like the rear window installation could be completed after we installed the wiring in the tail section and fuel tank.

The tail was attached shortly after the wings in April of 2017, and the vertical stabilizer and rudder followed shortly afterwards. Next we attacked the bubble canopy, which on an RV-12 hinges forward — similar to what you might find on a Diamond. This task required our first attempt at fiberglass work. You might not think that would be necessary on an aluminum airplane, but it was and it wasn’t the last of the fiberglass work either. The EAA offers training courses for homebuilders on things like sheet metal, fiberglass lay-ups, and electrical wiring to name a few, and I’d highly recommend taking those if you’ve got your sights set on building your own plane.

Installing the landing gear

By the end of 2017, the canopy was on and we were ready to install the landing gear, and this is when we started to outgrow the garage. The problem was that I couldn’t have the vertical stabilizer on and the canopy open with the landing gear on or the canopy would have hit the ceiling. Those items were temporarily removed so we could proceed building, though it became obvious that we would need to move to a larger location soon.

Soon we were on to the avionics, so we still had a lot of work we could do in the garage without a canopy. For the RV-12, Van’s offered two choices of avionics suppliers: Garmin and Avidyne.

We talked with both at Oshkosh, and not seeing a major difference between the two, we chose Garmin due to the fact that I have been flying behind the G1000 for a while now and was pretty comfortable with it. Other than having to do some minor body contortions to get all the wiring installed, that part went fairly smoothly and before long it was time to move.

At this point, most people would head to the airport and work at a hangar, but fortunately, Blackstone has a large heated garage with a high ceiling, so I gave up my parking space in that garage and moved the plane there, as well as my work tables in preparation for the final kit — the engine.

Engine installation

Unlike a lot of other kits available, there was only one choice for engines from Van’s and that was the Rotax 912 ULS. The good news is that this is an excellent choice. We see a lot of samples from that engine and they virtually always look great. The big difference between this and other 100 HP selections is that it has liquid-cooled cylinder heads. With that present, it can run either unleaded fuel or leaded fuel, so now I have the option of buying my own fuel instead of always having to buy airport fuel.

The engine is also equipped with altitude-compensating carburetors, so no mixture adjustments are necessary; one less thing for the pilot to worry about.

The engine was hung on December 21, 2018, a banner day in any airplane’s life. Everyone was excited, things are coming together, we’ll be in the air in no time now.

Well, here it is six months later and we still aren’t ready to fly, but as I said at the start of this article we are getting close. We flipped the master switch last weekend and powered up the avionics for the first time. Nothing caught on fire and the Garmin GX3 started just like it should, so that was another step in the right direction. We’ve rented a hangar at Fort Wayne International and will move it there at the end of the month. From there we’ll install the prop and start the test-flying process.

Time invested

I get asked occasionally how many hours we have in it and I really don’t know. Seems like keeping track of that would just make you depressed. With a project like this you have to just keep plugging away and sooner or later, the end will happen. In our case it’s been later, but the project has been fun and I’m glad my wife and I took it on. Still, I don’t think I’ll tackle another one any time soon. I’ll report back next newsletter, once we’re in the air!

By Ryan Stark|2024-09-18T14:08:56-04:002023|Aircraft, Articles|Comments Off

Building an RV-12 (Part 2)

I have been a pilot since 2005, and while I have done a fair amount of flying since that time, I have always rented the planes I have flown. This has both advantages and disadvantages, but for me the advantages have always been greater. Since earning my license, I have never really had any place I needed to fly. I have taken trips to see my in-laws around the Chicago area. I have picked up my Mom from various business trips that she’s taken, and I’ve done a few business flights, but none of these things were consistent enough need to warrant my own plane.

The ownership dream

It’s not that I haven’t been tempted, mind you. Like most pilots, I have my favorite aircraft (Republic SeaBee, Lake LA-4, Cessna Skymaster, to name a few) and have often dreamed of driving to the airport, opening up the hangar, and seeing my own aircraft sitting right there just waiting to be fired up. Having a window in my office doesn’t help either. Looking out on a nice sunny day, I feel a strong pull to stop when I’m doing, head to the airport, and take off, knowing that my airplane will be ready to go. However, obligations to family and business have kept those dreams at bay.

It helps that I can rent possibly the nicest Cessna 172SP in the tri-state area virtually anytime I like, so I can satisfy my flying itch when it needs scratching. I can also say that I have really appreciated not having to deal with the hassles that inevitably go along with ownership, like oil changes, annuals, and the guilt I’d feel when I go three to four months between flying.

Working in the oil analysis business, I can see the problems that develop in aircraft engines when they aren’t flown enough. Still, when you rent an aircraft, you never really know it like you would as an owner. All the little quirks that might identify a particular airplane are lost on me and if something changes in the one I fly, I don’t know if it’s a normal occurrence or possibly a problem.

Enter the RV-12

All of this changed with the unfortunate passing of my father Jim Stark back in November. He was assembling a Van’s RV-12 kit plane at the time of his death. It was always his dream to build an airplane, but until he retired and moved to a different house where he actually had some room to work, building an airplane was never in the cards.

I was the prime motivator in getting him working on an airplane, though I was never really interested in building one myself. If I were to ever get a plane, I would just bite the bullet and buy one, skipping all of the time it takes to assemble once, which can easily stretch out into a multiple-year endeavor. However, when Dad died I suddenly found myself with a half-finished airplane and a bunch of tools I don’t know how to use. So after some discussion with my wife, we decided to jump in and start building.

One of the big factors in this decision was how fun the RV-12 is to fly. I took a demo flight at Oshkosh last summer and decided that this was a plane I could easily get used to. The only downfall was that it only had two seats, so I couldn’t take my wife and kids anywhere at the same time. But I could see that this was a good introduction to aircraft ownership and also fun to build.

The up-side to building your own plane is you will know exactly how it all goes together and you can also do all of your own maintenance, which can be a big time- and money-saver down the road. Plus, depending on how the building goes, I could make a 4-seat RV-10 my next project and then I’d have something the whole family could take somewhere. But that’s getting ahead of myself.

Attacking the learning curve

I have what I consider to be a fairly strong mechanical background, but I’ve never done anything on an aircraft other than fly it. So far, building the RV-12 has been an adventure. The laboratory business is all metric, but I quickly learned that the metric system has no place in the aircraft industry. In fact, in some areas like drill bits, they don’t even use standard measurements, so buying my drill bits at the hardware store is out.

It also appears that deburring parts will be a large part of my life for the next few years. Fortunately my wife is ready and willing to help and will probably be the driving force in getting this project done. Deburring parts is a good place to start, at least until she is strong enough to run the rivet gun (better start hitting the gym, baby!).

its (a tool box and a section of wing), so I bought those and have been trying my hand at running a rivet gun. The results weren’t pretty, but I keep saying to myself that I’ll be more careful when it comes time to actually work on the plane. At least I hope I will.

I also bought a set of DVDs that show exactly how to build the RV-12 step by step. I know this is something Dad wouldn’t have approved of (he never met a set of instructions he didn’t throw away), but I don’t have the advantage of having an A&P license like he did, so I’ll take any help I can get. At this point, I’m just getting started, but with any luck the project will move quickly. Now if you’ll excuse me, I’ve got a fuselage to finish!

By Ryan Stark|2024-09-18T14:10:08-04:002023|Aircraft, Articles|Comments Off

Emergency!

Unless you rent just one plane a lot, you never really know about a rental plane. You would like to think that it sees careful maintenance all the time, and I’m sure most of them do, but as long as some other person is flying it, it could have problems lurking that don’t show up every flight. Like most pilots, I would like to own a plane someday — something I could fly a lot and get familiar with. Unfortunately, a Republic SeaBee isn’t in the cards right now, so I’ll be renting for the time being. That leaves the possibility for unknown problems lurking that have to be dealt with on the fly (so to speak).

Half power

For me, my first experience with a problem in a rental was actually during flight training. I was flying a Cessna 152 out of Fort Wayne International. I was just going up solo for some touch and go’s and on my first climb-out the engine went to about half power. Thankfully it stayed at half power and I was able to fly the pattern and land without incident.

When I got back in to the flight training building and told my instructor what happened, I got a sense that she didn’t believe me. And sure enough, when we both took it up, everything was fine. She mentioned something like, “I’ll bet there was water in the tanks” (I thought, No, I sumped the tanks and they were clean — I do work in a lab, dammit!) and that’s the last I heard about it. Of course, I was renting the plane, so I don’t know if it had happened before or after my incident, or if something was fixed afterwards that may have been the cause.

In any case, I didn’t panic and made a nice landing (the plane was reusable) so really didn’t think much about it until several years later.

When suddenly…

I have had my private pilot’s license for a few years now, and I have been renting a 172N with the Continental O-300. I got checked out in it just fine and had taken a few flights previously by myself. On this particular day, I went up with my Dad (Jim Stark, Blackstone’s founder) and his wife on a sightseeing trip.

We flew north for about 30 minutes looking at the lakes of northeast Indiana, and we had just finished a turn south to head back when the engine started shaking. No little shudder either, but the kind of shaking a dog would make trying to pass razorblades — at least what I would imagine a dog would look like. My dog was never so dumb as to eat razorblades to start with.

Anyway, the engine started shaking really bad. My father (also a pilot) initially said “Get the carb heat on!” and I thought, of course! Carb heat! Continentals are prone to carb ice and I have had nightmares of having to force land an aircraft for just that reason. I’m not sure if I would have thought of that myself, so I was sure glad to have him sitting in the right seat.

I pulled on the carb heat so hard I thought the knob might come off. We sat expectantly for a minute, both waiting for the engine to smooth out. Unfortunately, that didn’t happen. We still had power, but the shaking was bad enough that the thought of a 30-minute flight back to Fort Wayne wasn’t appealing, so I looked at Dad and said, “We’re going back to Angola to land!”

Angola is a town about as close to the northeast corner of Indiana that you can get. It has a beautiful airport with a paved 5,000-foot east-west runway. We were only about five minutes away, but as you can imagine, it seemed to take about an hour to get there.

The carb heat was on the whole time yet the engine never smoothed out, so I figured the engine had some serious issues. The landing was uneventful and as we pulled up to the ramp the engine was still shaking, so we decided to do a mag check.

The right mag check produced no change, but the engine almost died on the left mag. We tested this several times to make sure it was correct and then shut the engine down. One of the best things about the Angola airport is they have an airport car that’s available for situations just like this. It was a late ’90s Ford Explorer that shook almost as bad as the airplane, but hey, beggars can’t be choosers.

I called the FBO where I rented the plane, told them the situation, and then drove home. After an hour’s drive, I pulled into the FBO, gave them the keys and paid my bill. Yes, full price for the time I had the airplane. No discounts for having to make an emergency landing and no allowance for my stepmother needing new underwear. It was okay though, I was just happy to be alive and back in Fort Wayne.

The bright side

Now, the good thing about renting an airplane is, when it breaks, all you have to do is say “Your plane is messed up” and leave. I don’t worry about having to schedule/pay the mechanic, call the people who were renting it afterwards and tell them to make other plans, no hangar fees, no insurance, no fixing knobs that got pulled off.

The bad part about it is that you really never get to know the aircraft and engine ¾ what’s normal operation and what’s not. After a few days, I get a call from the FBO manager who said the engine had a stuck valve. I was fairly amazed because I suspected the horrible mag check denoted something electrical as the problem.

We happened to be doing the oil analysis on this engine, so I checked that to see what it looked like. Aside from a little excess copper, it looked pretty good. However, the O-300 does have bronze exhaust valve guides, so this should have been a warning, at least to be on the lookout for valve problems.

Signs of the problem

Since this incident, I have learned that a really bad mag check is a common symptom of a stuck valve. Some other common symptoms are below.

Morning sickness — When an engine starts rough first time consistently, not just in the morning, without plug fouling
Temporary roughness on climb out or in cruise — this happens when a valve momentarily sticks, then shakes loose
Intermittent rough idle that’s not caused by carb ice (this needs to be ruled out)

If I had been the sole operator of this aircraft, I might have identified some of the other symptoms and put two and two together. Instead, I was not aware of any issues at all. In all fairness, maybe there weren’t any, I don’t know. But I know these symptoms now and I’ll be sure to look for them in the future.

By Ryan Stark|2024-09-18T14:17:40-04:002023|Aircraft, Articles|Comments Off

Building an Engine Dehumidifier

Continental and Lycoming typically rate their engine life from 1,600 to 2,000 hours of operation between overhauls on most models. However, the only owners likely to achieve that kind of rated performance are those who use their aircraft on a nearly daily basis. Why? The reason is not the flying. It’s the parking!

A primary culprit for premature aircraft engine overhaul is corrosion caused by condensation that occurs after shutdown. Aircraft engines that are used daily frequently reach their rated TBO because liquid condensate is boiled off on a regular basis. Low use rate often results in reduced engine life.

Air Inlet Fitting In Oil Filler Cap

As the engine cools and the internal temperature drops below the dew point, liquid moisture condenses out of the vapor and clings to internal engine surfaces. This liquid water then resumes its ongoing process of eating up your engine from the inside out. However, if the dew point can be made sufficiently low, then liquid water will never form. This engine dehumidifier provides a continuous positive pressure injection of extremely dry air (dew point approximately -100^oF) on a 24/7 continuous flow basis. It is recovered at the crankcase blow-by vent, returned to the pump, dried again and re-injected in the oil fill port of the engine.

How it works

The dehumidifier is connected the engine as soon after engine shutdown as possible, before the engine cools. It is then run on a 24/7 basis. A small aquarium-type air pump forces ambient humid air though plastic bottle containing silica gel (this is the stuff used in shipping and storing aircraft engines and electronics).

Air Fitting For Oil Cap

The silica gel has a great affinity for moisture and literally sucks it out of the air. The dried air is filtered and injected into the engine crankcase. Any moisture inside the engine vaporizes with the incoming dry air and is moved by the constant positive pressure from the air pump to the crankcase blow-by vent, then back to the pump and the silica gel dryer. At some point in time, the silica gel will absorb all the moisture it can hold. This is obvious because about 5% of silica gel crystals are dyed blue that changes to a pinkish color when saturated with moisture. At that point:

Remove the saturated silica gel from the bottle
Spread it out on a cookie sheet
Heat in oven at 275^o F until the silica turns blue again
Cool and return to the bottle

Disassembled air pump. Remove the felt
filter in the bottom of the pump and plug
the hole with glue.

The frequency of this recycle rate will depend up the humidity of the environment. This may vary from months or more in dry regions down to just a week or so in the humid southeastern United States. Adding more silica gel to the bottle will extend the service interval.

Build your own

Connect the drier output via Tygon plastic tubing to the engine oil filler cap. A return line of Tygon tubing is fitted to the crankcase blow-by port. The preferred means of connection is to drill a ¼” hole in the oil filler cap and then install a short standpipe to the cap. I modified the oil filler cap by installing a hollow ¼”-20 carriage bolt. (I used a lathe to cut off the threads on the leading ½” of the bolt. This permits a slip fit of the Tygon dry air supply hose.)

The hollow bolt was then installed on the oil fill cap. Additionally, I made a ¼”-20 threaded Delrin plastic plug to cap this little standpipe during flight. Also, you will need to make an adapter to fit the crankcase blow-by tube. This can be a rubber stopper drilled to fit the Tygon return hose or a piece of rubber tubing with the return Tygon tube hot glued into it.

Please note that you will have to also devise a plug for the freeze-emergency blow-by vent located few inches up the blow-by vent pipe inside the aircraft engine nacelle. This can be a rubber flapper that normally closes the freeze vent. If the blow-by tube is frozen shut, crankcase pressure will push the rubber flap open.

The dehumidifier components consist of:

A vibrating reed “silent” type aquarium air pump
Two-liter plastic pop bottle with screw on cap
Airstone aquarium air bubbler
Ten feet of 1/8″ bore Tygon plastic aquarium tubing
Twelve inches of 3/16″ outside diameter (1/8″ inside diameter) rigid plastic tubing
One pound of 5% blue dyed silica gel
¼-20 custom air fitting hollow bolt
Pump air intake tube

Note: Low-cost aquarium pumps do have an irritating 60 Hz buzz caused by their vibrating reed design. So-called “silent” pumps are the same design but are supported in a manner that will minimize noise. If you spend a lot of time in the hangar, I strongly recommend the “silent” type pump.

To construct the dehumidifier, you will need an X-acto knife, a drill and ¼” and 3/16” drill bits, a hot glue gun, and gel super glue.

Extending the dessicant recycle time

The following modification can extend the intervals between service times for the desiccant. It revamps the dryer cycle from an open- loop system into a closed-loop. Dry air is still injected as before into the oil filler neck, but in addition, a vacuum line is attached to the crankcase blow-by tube that returns dry air back through the engine. This eliminates the continuous drying of external incoming humid air into the system and provides for continuous circulation of ever-drier air in the crankcase.

Implementation

The air pump must be converted to a blow-and-suck configuration. To do this you will need to make an additional fitting for the air intake port next to the air output port on the pump. Drill a 3/16” hole about ½” to the right of the exhaust port. Remove the felt filter in the belly of the pump case and plug the hole with glue.

Pump Return Line Installed In Blow By Port

To work as a vacuum pump, the pump case must be made airtight. This is done by disassembling the air pump case (two screws) and applying RTV silicon aquarium cement around the entire case seam and around all four sides of the power cord strain relief. Then reassemble the case and allow it to dry. Also, add RTV glue to any screw heads or tape over recess holes in the case bottom for an airtight seal.

You will also need to make an adapter fitting such as a rubber hose or rubber stopper fitted with a length of the Tygon tubing to serve as an air return to the pump.

Fabrication

Drill two 3/16” holes about ¼”off the center in the top of the bottle cap, close enough to the center to allow easy tube clearance of the bottle neck interior wall. For the pump inlet input, insert a 2” length of the rigid tubing in one hole and hot glue it into place. Insert the remaining 10” rigid tube in the other hole and hot glue it so the bottom end of the tube is positioned about 2″ from the bottom of the bottle.

Use a 1″ length of the Tygon flex tube to connect the aquarium bubbler airstone to the end of the longer rigid tubing. The Airstone is used as a dust filter to keep silica gel particles out of the engine. The airstone should lie on the bottom of the bottle.

To prep the silica gel, it in your kitchen oven at 275^oF until the dyed silica gel pellets turn blue (they are pinkish when saturated with moisture). Open the bag and pour the contents into a clean and dry two-liter pop bottle. Insert the airstone/tube assembly, work the airstone to the bottom of the silica gel, and tighten the cap. Do not delay, as it will absorb moisture from the air.

Open-loop dryer assembly

Use about a foot of the Tygon tubing to plumb the air pump to the short air input stub. Connect 6 feet or more of Tygon tubing to the airstone-equipped exit port, then to the air fitting on the oil filler cap. Connect the pump return line to the crankcase breather port via an airtight rubber seal.

Note: All connections and seals must be a leak-tight fit. Mating via the crankcase blow-by vent tube (usually located near the firewall) may be done by inserting a piece of the rigid tubing through a 3/4” closed-cell-foam ball or a tightly fitting rubber stopper.

A secondary modification required is a plug for the freeze slot in the blow by tube. This can be a rubber flap around the blow-by pipe that is normally closed over the freeze slot, but is pushed open by crankcase pressure if the exit end of blow-by tube end should freeze shut. Finally, a foam plug fitted to your aircraft’s air intake with a “REMOVE BEFORE FLIGHT” flag attached will close up the system circulation (in the case of a crankshaft position that leaves an intake valve open).

By Ryan Stark|2024-09-18T14:19:35-04:002023|Aircraft, Articles|Comments Off