Jim Stark | Blackstone Laboratories

About Jim Stark

Jim Stark passed away peacefully at his home in Ossian, Indiana on Nov. 20, 2015. He was 73. Jim was an inventor, entrepreneur, pilot, musician, writer, workshop tinkerer, mechanic, and an all-around interesting guy. He enjoyed happy hour (three-beer limit unless scotch was available), playing guitar and the ukulele, traveling and camping with his wife Kathy, passionately rooting for Purdue, hot tubbing, writing stories, John Prine music, and checking himself out of the hospital. Jim and Kathy played music wherever they went on their travels across the country. Jim founded Blackstone Laboratories back in 1985, a successful company that is still going strong today. He was building his own airplane – a Van’s RV12 – just before he died. Jim survived a tour in Vietnam, crashing an airplane, two heart attacks and two heart surgeries, jumping out of an airplane (barely) when he was 70, and the doctors in Indianapolis before lung cancer got him in the end. His spirit is among the stars, and he will be greatly missed by all who loved him.

Landslide!

Imagine the awesome event of a landslide. There’s no doubt it’s a brutal force of nature. If you’re unfortunate enough to be caught in one, you might not survive. A landslide is gravity pulling terra firma down a slope with such force that it takes all things, natural and manmade, with it. The very earth that supports us unmoors from its surroundings, changes shape, and becomes destructive. While it may not be obvious at first glance, this landslide can help us understand oil analysis.

Take a picture

Back to your mental image of the landslide: it starts off with a few pebbles rolling down a hill. Those pebbles strike others, and the dirt slide gains momentum. The process escalates and the mass of the movement increases. Larger rocks and patches of earth are dislodged, and the process continues until the whole hillside is involved, taking trees, boulders, and anything else in the way. Now stop: Take a mental picture of the landslide in full force. Step back and look at the frozen picture. Everything on the hillside that started off peacefully and at rest is in the process of roaring toward the bottom of the slope.

If you looked at your picture of the landslide from afar, you’d see a cloud of dust and dirt at the front edge of the sliding mass, and lingering far behind it. The dust cloud itself would actually hide much of the larger detail of rocks and trees crashing along the slope. Without looking at the larger debris contained in the mess, could you determine the makeup and extent of the landslide from the dust cloud alone? For the most part you could, and that’s how oil analysis works.

Normal vs. abnormal

One of the limitations to oil analysis is that we can only tell you about the wear metals that we can see with the spectrometer, which are between about 1 and 15 microns in size. (How big is a micron? One-millionth of a meter. One inch contains 25,400 microns. The period in this sentence is about 615 microns.)

If you have a mechanical problem with your engine, the oil filter should collect the larger metallic particles (usually those larger than 40 microns). These are the boulders in the landslide. There is also a wide range of rocks and stones present in the landslide that don’t become airborne. They still ride the slide to the bottom of the hill, but they don’t hang suspended in the dirt cloud. These are the particles that fall out of suspension and don’t make it to the lab with your oil sample.

Then there’s the dust cloud. We compare the “dust” we see in an oil sample to what is average for a particular type of engine, transmission, differential, etc. We expect all mechanical machines to produce wear in the course of normal operation. But there is normal wear, and there’s abnormal wear. When we find abnormal wear in your “dust cloud,” we may be looking at a potential landslide in your engine.

Avoiding the trees

Fortunately, we don’t have to wait for a landslide to occur before we can determine what’s going on your engine. While the dust cloud accompanying the slide is a one-time occurrence, we can repeatedly analyze the oil from your engine and see trends developing. One snapshot gives you a look at whether the dust we find appears normal or abnormal. But a series of snapshots gives us a clearer picture of the condition of the engine. By trending the results from one oil change to the next, we can see whether the dust cloud is growing or subsiding. If it’s growing, eventually there will be boulders and you’ll need to take action to save the engine.

Occasionally we are asked about the dust: How much is too much? In other words, when someone has a particular metal that’s reading high, they often want to know how high it needs to be before they really start to worry. The answer is, there’s no single answer.

Lots of things affect the amount of wear we find — the type of engine it is, how it’s driven, and what conditions it’s operated in. What’s more important than the level of wear is the wear trend that’s developing. Someone who routinely races a Subaru 2.5L engine in Las Vegas is probably going to find higher wear on a routine basis than a person who uses the same engine to mainly go to work and the grocery store in Minnesota. If the racer’s wear is always high, and it always reads at about the same high levels from sample to sample, we’d probably consider it normal for that particular engine. If the grocery-store engine was producing low, steady wear, and then wear suddenly jumped up to the racer’s levels, we’d worry. That’s why it’s important to establish wear trends for your particular vehicle, and why we can’t always say, “Okay, when iron gets to X level, it’s a definite problem.”

Avoiding the full-on, catastrophic landslide is not hard to do if you practice routine oil analysis. To keep the boulders and trees out of your engine, pay attention to what you find when you change the oil or have it changed. Some metals are normal in new engines, but once past 10,000 or 15,000 miles, you should not be normally finding any metals that you can see. If you do find metal, it’s probably not too late to stop the slide — but it’s better to avoid it in the first place, if you can, through the trend analysis of your engine’s wear.

By Jim Stark|2024-09-19T09:01:39-04:00June 12, 2024|Aircraft, Articles, Gas/Diesel Engine|Comments Off

A harrowing tale

It was a late and dark night in the California mountains. Our 36-foot, hinged-in-the-middle rig was straddled in a sharp “V” across a two-lane mountain highway, with no obvious way to get unstraddled. Behind us was a vertical rise in the terrain going straight up, in front of us a sheer drop off that appeared to be a black abyss. Up and down the highway the pavement curved to invisibility. We were sitting ducks for any unsuspecting semis that may have been motoring innocently along the route at highway speeds. I could imagine our stranded rig suddenly coming into view of a trucker who knew in a flash his goose was cooked: He could shoot off the cliff or T-bone us. It would be a spectacular crash.

How we got in this predicament is embarrassing. It was the fourth consecutive driving error on my part and it could have been my last. My truck was not ideal for towing: I had the off-road package, not the towing package. Gas stops in the California mountains are infrequent, making it nearly impossible to drive on the bottom half of the tank. We had planned to arrive on the west coast at 6:30 pm. But we needed gas, and no gas was available in the foreseeable future, so we had to turn around. We’d passed a Shell station 35 miles back and the only solution was to drive back and fill the tank.

We were quite tired by this point, and frustration was setting in. The drive back was up and down steep grades. When the station finally came into view we were coming down a steep grade and we saw the station on the right. What we missed was, the road curved sharply to the right and the station was actually on the left. This is important, as you’ll see.

After filling up, I ran over a tall curb getting back to the road. It wasn’t a huge problem, but the camper doesn’t have much ground clearance and the scraping noise was painful. I turned left to finish our drive to the coast. Kathy dozed in the right seat.

Maybe 45 minutes later, I started wondering where all the hilly terrain was that we had driven over getting back to the gas station. I woke Kathy and asked her to turn on the GPS. You can probably see where this is going, right? We were headed east, not west! The frustration level immediately increased to a silent roar inside my head.

I needed to turn around (again) but there were precious few places to do so. I finally found a wide spot in the pavement, just wide enough you could pull a car clear of the road. I pulled as close to the side of the mountain as I could and swung a hard left to make the u-turn. As we neared the far shoulder Kathy screamed, “STOP!” I raised up off my seat for a look and our right tire was about to drop off the side of the cliff, into the blackness.

What to do? I was already jack-knifed. I didn’t know if I could gain anything in reverse but I sure couldn’t go any further forward. After a moment’s consideration, I cranked hard right in reverse and forced the jack-knife as tight as I could without breaking anything. I cranked hard left, shifted to 1^st gear and popped the clutch. I’ll never know if that right front tire caught air or not, but we didn’t drop off the cliff.

We finally made our destination at 11:30 that night. We had to stop at the Shell station a second time to assure we would make it. All the rest of the drive I was thinking, don’t make a fifth error. It will surely be the end!

The trailer

We were pulling new camping trailer we had bought the week before we left. I had no experience towing loads other than incidental occasions in my 50-plus years of driving. A couple times unreasonable trailer loads had nearly overwhelmed whatever vehicle I had been driving at the time. This was experience I didn’t want to repeat.

We had been planning to drive to the west coast for some time, but only at the last moment did we realize we had the funds to buy a camper. Kathy used to own a trailer that she pulled with a half-ton pick-up. It was an older unit and heavier than what we eventually bought, a 16-foot unit that weighs just short of 3,000 pounds empty.

I drive a Toyota Tacoma and until I actually studied the owner’s manual about weights and capabilities (well into our towing trip), I had no idea the limits of my truck. I made the trailer purchase based on hitch weight, a number I looked up as we were talking to the camper salesman. He said we could pull this unit and I was little less than shocked to find he was right. The hitch weight of the trailer we were looking at was about 50 pounds less than the Toyota book suggested I could put on the hitch. With that fact alone, we went ahead and bought the trailer. The salesman said: “You won’t even know the trailer is on there!” How many times have you heard something like that?

The experiment

I wanted to leave my old oil in the crankcase to demonstrate how abrasive, used oil can affect the bearings when you work an engine hard. Toyota engines don’t make much metal under any circumstances, and for the near 100,000-miles I have driven this truck, I’ve never seen as much as 1 ppm lead in the oil from the bearings. Typically I change oil every 9,000 miles. Most of my driving is easy: country roads at moderate speeds, only rarely hauling anything, though I don’t hesitate to bump redline often…like nearly every time I drive. Don’t ask why. I’m out in the country and I just like the feel of the engine as it accelerates past 5,000 rpm. I’ve always contended that driving an engine hard doesn‘t hurt anything so long as you stay within redline. I’m still of that opinion.

Anyway, for this trip, I wanted to demonstrate that you can get poor bearing wear if you work an engine hard with dirty oil in it. I had more than 5,000 miles on the oil when I bought the trailer. Miles on the oil were accumulating fast and I still hadn’t left. I knew the next drive was going to be more than 6,000 miles…and at the last minute I chickened out. I could imagine the oil was going to be running warmer than usual and at 11,000 miles or so, the 5W/30 oil could turn to sludge and I’d puke the engine. I’d never live that down.

So I changed oil at the last minute and also had the rear differential and transmission serviced since I knew those gearboxes would run warmer as well. When I got back from the drive I knew I would have a nice apples-to-apples oil analysis comparison for the engine: the first analysis showing routine wear under no-load driving, the second I assumed would show much higher wear after abusing the engine to the extreme with a heavy load in mountains and across deserts.

Get up & go!

Kathy had a week to load the camper. I realized I had no idea how much weight she was putting into it. I thought momentarily about driving to a local stone quarry and having it weighed. That thought didn’t take root. Life is a gamble, right? Start to finish. In the end I loaded up a full row of firewood in the front of the truck bed, threw in the heavy cooler, hooked up and towed the load into a cold, gloomy, late October evening.

The first leg was 100 miles due south. There was a nasty, gusting crosswind from the west and it had me talking to myself for a couple of hours. I was sincerely wishing for another 50 horsepower and a heavier truck. Then we turned due west into the wind and things started settling down. I had Kathy drive to tell me how it felt compared to her half-ton pulling her old camper. She liked the feel of it. My heart rate was trying vainly to return to normal and her opinion helped a lot. Being married to an excellent driver is a blessing I hope you enjoy. I even started getting some honest hope that the next 6,000 miles wasn’t going to be a nightmare.

We crossed the fields and plains and wove our way into the mountains. The driving got easier. I never did get to the point the trailer salesman suggested (“You’ll never know it’s there!”) but mile after mile, the tension eased and we started having fun. We made Las Vegas a day early even though the normal approaches to the Hoover Dam were closed, causing long detours. We parked at an RV park just on the south side of Vegas proper and at the appointed hour, enjoyed talking about Blackstone to a large group of RVers.

Mountain driving got serious after we toured Death Valley and headed west across California. The climb out of Death Valley was memorable. From 282 feet below sea level to about 7,000 feet above in a very short stretch of road, we did our hardest climbing. Twice the steep grade got me down to second gear. That’s second gear on an Interstate highway and no one else was doing much better.

All this hard climbing, and all through the trip the coolant temperature didn’t vary at all. It just sat there like the needle was painted on. I’ve had normal cars overheat climbing up places like Pike’s Peak, just plain old cars with hardly any load in them. Here’s my Tacoma (we started calling it Taco-Ma) leaving Death Valley pulling 3,000 pounds of trailer and all the stuff Kathy packed in it along with a heavy cooler and a full row of firewood, and we got no variation in water temperature. I’m more than impressed. I’m amazed!

Gas mileage, however, was terrible. Normally Taco-Ma averages about 22 mpg on the highway. For the total trip, we averaged 12.6 mpg. There are long stretches of highway in the west where you can’t find gas. We had one “white-knuckle” drive that left us with less than a half-gallon by the time we found a station. After that, we started carrying four gallons in the bed of the truck.

Drive it like a bug

Towing the trailer reminded me of driving the original, underpowered VW Bugs. They could run about 70 mph on the flat, full-out. If you wanted to not slip too slow on the next upgrade, you held the petal to the metal on the downgrade and held it there, using momentum keep the speed from decaying. The end result is you keep the petal planted hard for most all hilly driving. Watch redline like a hawk. Shift when you must. Don’t let RPM sag too low. Driving like this, no wonder we lost ten mpg on this trip.

The drive took us to southern California for a couple of days, then back into Nevada and on down to Tucson for a couple more days. We crossed New Mexico, entered Texas down near El Paso where immigration problems are evident. We passed through a check station and as we approached we passed by a dozen sensors of some type staring us in the face, like so many cameras of a sort in a bank of equipment. They can apparently see through cars, trucks, and campers because they let us pass without much thought. There were no stowaways aboard.

We drove Texas diagonally ending up at Texarkana. You can drive 80 mph in southwest Texas. We didn’t. Could have, I suppose, though by that stage of the trip, I’d had enough of pushing the engine.

When Taco-Ma’s V-6 shoulders into a hard, long pull (which was invariably accompanied by Kathy and I shouting in unison, “Go Taco-Ma, go!”) you hear a sound of seriousness. The engine is an airpump. When you work it as hard as you can, throttle mashed to the floor, mile after mile, the serious roar is the scream of air intaking, passing through the core of the engine, and the jetting out of exhaust. It’s a heavy growl, an awesome sound. I’d heard it enough by the third week. And by then I was thinking seriously we might get home with no serious problems. The day-long drive across Texas was made about as cautiously as I could make it.

From the barren plains of Texas to the beauty of Arkansas was dramatic. Arkansas comparatively, looked like the Garden of Eden; like less populated parts of Wisconsin or Michigan. It also felt like we were closing in on home. Mountains and deserts behind us. Now just stay awake and drive.

We finally got to use the firewood in Tennessee. We burned it all in one night and what I learned was, the extra weight in the bed had been a nice asset. We had played with weights and balances daily for the trip, trying to find the magic balance for perfect handling. Turns out, using the firewood made the most difference of anything we’d tried. Less weight all around and almost none in the truck bed left the unit squirrelier than for any other trip leg.

The moment of truth

As soon as we got back I had the engine oil changed, along with any other gearboxes I hadn’t already changed out earlier. A day later my emailed report arrived. To my amazement and delight, engine wear hadn’t changed at all! Not a bit! The extra 1 ppm iron that turned up is from the longer oil change (6,672 miles vs. only 5,175 miles for the pre-trip sample). Iron tends to accumulate with more miles on the oil.

I was wrong in my assumption that towing and mountain driving would cause excessive wear. In large part I think this can be chalked up to the engine type. Perhaps it would have turned out differently had I been using old oil; the metals could have conceivably accumulated to levels that would have made the oil abrasive, which will cause excessive wear. But with clean oil, I didn’t find any change at all. Taco-Ma did us up right.

So will the same thing happen for you? If you run autocrosses or run at a drag strip or do anything other than ordinary driving, does your engine wear change as engine stress increases? Sometimes it does, but in the end there’s no hard and fast rule. So much depends on the engine, the driver, and the environment.

That’s why it’s no good to say all engines should have an oil change at 3,000 miles or 5,000 miles or beyond. The oil and engine combination that works for one guy may not work for the next, simply because all situations are different. It seems logical that if you don’t keep clean oil in the sump when loading the engine heavily, you will wear more at bearings. But if you run clean oil? Maybe no change. Try it and see.

By Jim Stark|2024-09-19T09:41:48-04:00July 28, 2023|Articles, Gas/Diesel Engine|Comments Off

Space Dust

Here’s a fact. Everything we turn up in analysis of your used oil had to get in there somehow. As obvious as that may appear, I hadn’t really thought about it until I ventured into making my own oil.

I built it up gradually, starting with a 10W base stock that was nothing more than refined mineral oil with nothing added. After running it a specific period and measuring the results, I started adding components, running the same miles, and repeating measurements. Eventually I ended up with a complete package that performed very nicely.

Every time I changed something in the oil, the results were measurable. That led to a low-level Eureka! — an affirmation of something I’d always known but hadn’t given much thought: Everything we find in oil analysis had to get in the oil somehow. What we find in oil was put there by the oil blender, came from the engine, or came from the environment.

There are many factors and variables to consider in how long you can use oil in an engine and in how long an engine will last. The most important of all those variables is keeping the oil, regardless of type, as clean as possible. Your air and oil filtration systems are critical players in accomplishing this mission.

The importance of air filtration

Leaving oil filtration for another article, just how important is air filtration? It is one of the most important factors in long-lived engines and long oil change intervals. It is a variable you can control.

Silicon is everywhere in the environment. We rarely think of it unless we see a dust storm in a desert or watch a farmer’s tractor operating in a cloud of dust, but there is no such thing as clean environmental air. If you let rain drops dry on your car or truck, by the time they dry they will have collected enough dirt to leave spots on your paint.

Dirt exists everywhere because it comes from outer space. Have you ever wondered why the most important tool in archaeology is a shovel? If a team of archaeologists went to study a 2000-year-old humanity site, they probably would have to dig down 30 feet to find what they were looking for. The reason old things are buried so deeply is that the Earth is constantly being showered by extraterrestrial dirt. You can’t escape it, even at high altitudes, and they only way you can prevent it from prematurely wearing out your engine is to collect it in an efficient air filtration system.

Controlling the dirt

I was recently speaking with a pilot about why his engine was wearing so poorly. He told me he liked to pull a little carb heat (in other words, unfiltered air) through his engine once he hit altitude because the air up there wasn’t a problem. Once I looked at his report, I saw his silicon level was quite high. He was wrong about the air up there not being a problem. In fact, there is enough silicon in the air at any altitude to cause poor engine wear. It’s important for any engine to filter the dirt out before it can do damage.

All engines wear and eventually wear out. Assuming a mechanical or contamination event doesn’t cut short an engine’s life, the amount of wear an engine’s parts leave in the oil is predictive of how long that engine will last. One of the most destructive contaminants that get into the oil is excessive silicon. The best wearing (longest lasting) engines we see have air filtration systems that keep silicon to a minimum in the oil. Regardless of the air filtration system manufacturers supplied for your engine, it is up to you to maintain it to perfection. Is your air filter up to snuff?

By Jim Stark|2024-09-19T09:44:18-04:00July 28, 2023|Articles, Gas/Diesel Engine, Marine|Comments Off

All About Insolubles

Once upon a time I lived in primitive conditions as a soldier in a war zone. We had few amenities, eating our three daily meals from a can.

The morning coffee routine wasn’t very refined, either. The cooks worked in a tent. They heated water for coffee in large 15-gallon pans over a gasoline-fired stove. To make coffee they simply dumped tins of ground coffee beans into the boiling water, and after it steeped for a while, the water turned brown. When it appeared to be the right color, the heat was turned down and the churning grounds—at least most of them—settled to the bottom. If you were early when you passed through the chow line, you got a top-of-the-brew serving that wasn’t bad. If you were late and your cuppa joe came from somewhere near the bottom, you could chew it.

We enjoyed the coffee grounds in our coffee as much as your engine enjoys insoluble materials in its oil. These days, there’s usually only one reason I find grounds in my coffee: the coffee filter failed for one reason or another. Usually, one or more of the filter pleats has laid down, letting grounds overflow the rim. But the insolubles in your engine’s oil are not quite as simple as the grounds in my Mr. Coffee machine. There are many reasons that insolubles form in a gas or diesel engine oil sample.

Insolubles are solids

Insolubles are the total solids we find in an oil sample. Insolubles are often caused by oxidation, which is a natural process that occurs when oil is exposed to heat or oxygen (in the air).

Oxidation leaves free carbon in the oil when the oxygen molecules combine with hydrogen. Virgin oil usually doesn’t have any insoluble materials in it. When it occasionally does, the most we normally find is a trace level. The insolubles in virgin oil are from the normal oxidation process of the oil. At least some of the insolubles in the oil samples we analyze are free carbon particles, which are hard particles that can damage sensitive, close tolerance parts like friction bearings.

Keeping insolubles within the normal range is important for anyone wanting to run extended oil change intervals, but it’s also important to anyone wanting to get the longest life possible from their engines.

Measuring Insolubles

There are various methods of measuring insolubles in oils. One way is to draw the oil through a very fine filter (½ micron) and then weigh the filter. The filter’s weight gain is reported as a percentage of insoluble materials by weight, compared to the weight of the sample that was drawn through the filter. Another measuring method rates the darkness of the filter patch compared to a standard.

The insolubles test we use at Blackstone is a centrifuge method. A measured volume of oil is mixed with a heated solvent, agitated, and spun at high speed. Insoluble materials collect at the bottom of a tapered glass tube and can then be measured as a percentage of the sample by volume.

The insolubles test is a good measure of how fast the oil is oxidizing and receiving contaminants from blow-by or other engine systems, and how effectively the system’s oil filtration is functioning.

Any contaminant in the oil will accelerate its tendency to oxidize, so the insolubles test is a good crosscheck when we suspect a contaminant like gas, moisture, or coolant. Excessive metals in an oil sample will also increase the oxidation tendency. So will frequent and/or extreme heat cycles. Stop-and go-driving is harder on engine oils (and creates more insolubles) than highway driving, because the engine experiences more heat cycles.

What Causes Higher Insolubles?

We like to see insolubles for gas engines at or below about 0.5% or 0.6%, depending on the type of engine. Some diesel engines are cleaner than others so the normal range may run from 0.5% to 0.8%.

As engines age insolubles in the oil tend to increase. You may think, judging from the appearance of a used diesel engine oil, the insolubles would be unbearably high. Actually, the blackness of these samples is from fuel soot, which is clearly distinguishable from, but also contributes to, insolubles. Fuel system and combustion problems will cause excessive soot. If we detect excessive soot in your (diesel) oil sample, we will mention it in the comment section.

If we found no contamination (soot, coolant, etc.) in your oil and your oil change intervals are normal, we often mention a problem at oil filtration as a possible cause of high insolubles. The oil filter could be inferior. Or, it’s possible the oil filter bypass valve relived if the filter was becoming restricted. The filter system bypass may also open upon cold starts when the oil is too thick to pass through the filter media, which may be partially restricted. Once the bypass relieves, the filter is effectively out of the system. Insolubles may also be forming because your oil use interval is too long for the operating environment of the engine, and your oil filtration system can’t keep up.

Insolubles are just one of the tests we provide to determine the condition of your diesel and gas engines and used oils. It’s an important test that helps us gauge the condition of your oil and engine, and helps keep you driving happily for many miles to come!

By Jim Stark|2024-09-19T10:37:16-04:00July 28, 2023|Articles, Lab Tests|Comments Off

Does Oil Brand Matter?

No matter who you are or what your oil analysis needs are, you have undoubtedly faced the question on everyone’s mind these days: What type of oil should I use?

Many people have very strong loyalties to certain brands of oil. They’ll swear by their favorite brand and assure you that anything else is bound to ruin your engine. But we’re here to dispel that myth. After nearly 30 years of testing oils from thousands of different engines and industrial machines, we have discovered a shocking fact: it doesn’t really matter what brand of oil you use.

But wait! Before you dismiss us as heretical, listen to what we do recommend. We always suggest using an oil grade recommended for your engine by the manufacturer and a brand that fits your budget. The grade of oil is much more important to performance in your engine than the brand of oil.

In fact, here’s another little secret. The oils you can find at any mass retailer, such as Wal-Mart or Meijer, are actually name-brand oils (such as Valvoline, Shell, or Quaker State), but with the store’s label on it. Think about it. A place like Auto-Zone is not in the business of manufacturing oil. They buy their oil from the big oil companies and put their name on the bottle. The only difference between the Auto-Zone brand and the name-brand oil is the name on the bottle and a few dollars per quart.

We analyze oils from our personal use engines (right down to our lawn mowers) religiously. We tend to choose oils that do not contain additives that can get in the way of elements we want to see in the analysis. For instance, many light, multi-grade oils use sodium as an oil additive. The sodium can mask antifreeze contamination.

If you want to see for yourself which oil is going to perform better in your engine, we recommend a test: run Brand A in your engine for a set number of miles or hours and have a sample analyzed. Then run Brand B in your engine for the same amount of time, and have that oil analyzed. You can compare the results for yourself, side by side, to determine which oil is best for you.

By Jim Stark|2024-09-19T10:31:20-04:00July 28, 2023|Articles, Gas/Diesel Engine, Industrial, Marine|Comments Off

Antifreeze: The Silent Killer

After analyzing engine oil for 30 years, I can safely say the thing that kills more engines than any other is antifreeze seeping into the oil. We call it the “silent killer” since there is normally no indication this dreadful contaminant is about to strike until after the damage is done. Neither you nor your mechanic can see it in the oil. The dealer won’t know it’s there.

We like to say engines speak before they fail, but in this case, you aren’t likely to hear much of anything until you hear just about the worst sound an engine can make. Oil analysis is the only way of knowing this sneaky killer is closing in on you. We can see it in the oil at a trace level, long before any harm is done.

We call people daily to let them know anti-freeze contamination is about to ruin their day. A typical reaction is, “What? That engine is running fine!” And they are right—the engine will, in most instances, run perfectly well until a bearing spins, oil pressure drops, and the engine destructs to the point of no salvation.

Some engine configurations are more susceptible to the problem than others: V-6s and V-8s for instance, are perhaps more prone than other engines. But no engine is immune (except air-cooled engines!). One would think that after 100 years of building engines, the automakers would get it right. To my knowledge no one has.

The problem with design

The engineers who design engines do a marvelous job of building lighter, more efficient and faster engines. But for every step forward in the process, there are compromises.

Building lighter engines necessitates working with new alloys for the various parts that are bolted together. Gaskets are used to seal between the parts. To get an engine perfectly right, they have to use parts that expand and contract with heat at the same rate, and gaskets that are hardy enough to seal well even after they age and suffer millions of heat cycles. You can imagine the engineers tossing in their sleep while wrestling with this dilemma.

A classic example of the problem was a Jaguar in-line 6-cylinder engine I once owned. I loved that engine with its long, high-end torque curve and mellow growl. It was probably the first duel overhead cam design that managed quiet chains in the days before belts were used. But for all its wonderful assets, there was this one drawback: they used an aluminum alloy head on a cast iron block. If you managed 50,000 miles on a head gasket, you were a very fortunate person.

With an in-line design, the anti-freeze contamination usually develops at the head gasket. With the V-designs, a more common source of the problem is intake manifold gaskets.

The manifold gasket supports the air/fuel system mechanism and straddles (and is bolted to) the heads. You can imagine the complexity of the problem of heat cycles. Block expansion forces the heads up and away from the crankshaft. The lowly intake manifold is not in a position to move in concert with the expansion. It would be like trying to ride two horses standing on the two saddles.

The result of this set-up is that intake manifold gaskets fail. Antifreeze starts seeping into the oil. It often takes quite a long while before the problem manifests itself in a failure, but it can also happen quickly. Since there are usually no obvious symptoms of the problem, the unwary engine owner usually drives the engine to oblivion.

Another common question we hear is, “How long until it fails?” Unfortunately, it’s impossible to predict how long an engine with an antifreeze problem will last. Many variables factor into the equation: the type of engine, how it’s driven, the environment it’s operated in, and—the most unpredictable of all—Lady Luck. Some people can limp along for ages with a slight trace of coolant that never turns into anything serious. Others turn up a trace and then WHAM! Faster than you can say “spun bearing” the engine fails.

Don’t quote me on this, but if I had to estimate the severity of the problem in car and truck engines today—judging from our oil samples—I would suggest 1–2 % of the cars and trucks in the road today are in the process of failing from antifreeze contamination of the oil. Fortunately, most antifreeze problems can be detected early with oil analysis, and in most cases we can save the engine before a failure. We would like to save all of them. But we can’t save anything until see the oil from it.

By Jim Stark|2024-09-19T10:09:24-04:00July 28, 2023|Articles, Gas/Diesel Engine, Marine|Comments Off

Protecting from Corrosion

Considering the relative inactivity of much of the general aviation fleet, it’s not surprising that corrosion is a hot topic. It’s also fodder for aviation oil makers to claim their oil is better than others at protecting engine parts from corrosion.

The frustrating thing when you can’t find the time to go flying is, your beautiful bird is languishing alone in a dark hangar accumulating rust on its parts and dust and bird doo on its wings. What to do?

If you can’t fly it, you don’t want to just ground-run the engine since it’s pretty well accepted that doing so may cause more harm than good. In the end, the path most often chosen is to “leave her sit.” But that’s the maddening part. You just know that corrosion has begun at the cylinders, cam, and lifters, as well as all the other parts that are parked above the engine’s oil level. “Dammit! Maybe I should go out and shoot some landings.” But you don’t. So the question still stands…what to do?

We get a lot of questions about which oil protects aircraft engines best from corrosion. If there were a sure answer as to which oil is best, someone would surely have come up with it. Since they haven’t, perhaps we should reconsider the question. Maybe what we should be asking is, “What can I do to prevent corrosion in my (not flown frequently enough) aircraft engine, regardless of the oil I use?”

Turned around that way, there may be an answer.

Water orbs

Oil and water don’t mix at the atomic level. Since there is no such thing as dry oil — both hot and cold oil suck moisture from the air like a sponge — the only way these dissimilar types of matter can coexist is for the moisture to ball itself up into minute spheres, so tiny that they can exist in suspension. If the water orbs get large enough they will precipitate, that is, fall out of suspension. But there is almost no limit to how tiny they can be. The longer the oil sits undisturbed, the more water it will accumulate.

Oil routinely has some moisture in it, usually at levels between 40–400 ppm. In amounts greater than that, it can start to make your oil look like chicken gravy. Once moisture sets in, heat and/or pressure are the only way to get it out. If you go out and fly for an hour, the oil temperature and agitation will dismiss the moisture droplets like unruly elementary students. The moisture accumulation process will start all over again once you pull idle cut-off, but at least you have the satisfaction of knowing that, at least for now, the fine film of oil clinging to the metal parts is not heavily populated with tiny balls of water.

Fighting corrosion

After you lock the hangar door, the dry (well, reasonably so) oil film doesn’t last long on all those parts that are parked about the oil level. If your engine is a dry-sump type, none of the parts are parked in an oil bath.

If you can’t fly, you might consider using a pre-oiler once a week to rebathe all the parts in oil. The oil from the pre-oiler will reach all parts that see oil pressure during engine operation. It would require only turning on the master and the oiler switch for a short while, no longer than it takes to check the lights and flaps during a preflight, a few minutes at most. The oil should reach all the way up into the rocker boxes and then drain to form a brief pool over the tappets and cam, parts that are notoriously prone to corrosion pitting in all but the most active engines.

After the pre-oiling dose, you could get out and pull the prop through a few blades (normal direction of rotation, of course) to ensure all moving parts rotate through a couple of full cycles. Further, you will be giving all the rod bearings an oily trip through the sump reservoir, for wet sump engines. (Some people are queasy about touching the prop, so running the starter is an acceptable alternative, if you have confidence in the integrity of the battery.)

Cold dousing all oil-wetted parts isn’t nearly as good as an hour’s flight, but it seems far superior to the ground run-up, or the more often chosen “letting her sit.”

By Jim Stark|2024-09-18T13:48:37-04:00July 18, 2023|Aircraft, Articles|Comments Off

Sudden Landing? Remember TWIT

Aviation is fraught with acronyms. There are so many acronyms that it is humorous to think the government still thinks they are a memory solution instead of the problem. I hate to add one more, but TWIT is one that may cause an unfortunate event in your life to turn out to be a good story instead of a tragedy. It is the word to remember should your (single) aircraft engine quit. You know, when the heat pump stops heating, when the cooling fan stops cooling, and/or when the roar of the engine that has always been your security blanket leaves nothing but silence ringing in your ears, uncovering your naked fear.

More than twenty years ago I was viewing the remains of an upside-down C-150 in a bean field with a couple guys from the Sheriff’s Department, when a civilian turned up. He was a lanky guy in a black suit with a camera slung across his shoulder. He asked me if I was the party that had left the airplane in this condition, and I admitted that I was the culprit. He said he was not only the undertaker in Paris, Illinois, but the newspaper photographer too, and when he gets a call like the one he got this morning, he didn’t know if he’d be taking pictures or measuring the body. With a grin, he pulled out a tape measure. “Looks like its only pictures this morning,” he said.

The saving grace of TWIT

I’ve had a long time to think about that and decided your early “engine out” training, as good and thorough as it may have been, could be improved upon with TWIT. Any engine out practice is good because if and when it really happens, you don’t need the tension of suffering the sensation for the first time. Few of us do first-time experiences well. So it is nice when you find yourself gliding around up there, sans engine, to have done it a few times before.

Everyone knows the first thing to do, which is to trim best glide speed. Don’t know it? Well, anything in the vicinity is okay. The idea, of course, is to give you the most time aloft for the altitude you are carrying. The reason that is important is that some prayers take far longer than others to complete. And if you happen to be one of those people who feels the need to pray with your eyes closed, well, you don’t want to waste all the glide time left with your eyes closed. It is a good idea to take a look at the terrain.

Trim

So the first letter to TWIT is for Trim, which hopefully gets you somewhere in the neighborhood of best glide. Your airspeed will be about 65–75, depending on the airplane. Our father…

Your flight instructor thought the next important thing to do was find a field to land in. With all due respect, that may not be the best idea. If you can hit a particular field from 5,000’ you are a better pilot than I am. You may pick the best field in your range of vision, but actually being able to hit it from altitude takes a lot of practice that we don’t generally work on. (Well…maybe the astronauts.)

My experience is, you will pick a field, and then see a better one as you get lower, and then a better one when you get lower than that. What makes it good is your ability to land on it, not its humongous size. It only takes a few hundred feet to land an airplane and you will find most fields at least that long. It is far more important to be landing into the wind so that length of field works. It is also nice to land without hitting anything. It is cheaper to buy a quarter acre of corn from a farmer than have to pay for his custom and recently rebuilt outhouse, which his insurance company will value in the tens of thousands of dollars.

Wind

So the second letter of TWIT is Wind. The first of the two turns you are going to make is the turn to base. You need to be adjacent to the wind. You probably know the wind direction, at least generally. If it is, for example, south, then turn east or west. If it is west, turn north or south. Which direction you turn will be decided on which direction has the best fields and the least structures. You don’t need much of a field, but when it comes to choosing one, the more options you have, the merrier.

If you are headed for a town or city, use some of that glide time to make a 180. A long walk out is better than hitting an unmovable object. Hopefully this is going to be the longest base leg you have ever flown. It will give you time to check your drift and verify the wind direction and speed. You might even stumble across a landing strip, if your GPS hasn’t already found one for you. If the wind is left, you are on a left base. If the wind is right, you are on a right base.

Initiate

You don’t pick your field until you see one that fits your sight picture for turning final. Few of us could hit a field from 5,000 feet, but all of us can hit the runway when turning final (well, almost all of us). If you are on left base, you are looking for the field on your left. If you are on right base, you are looking right. When the sight picture is what you are used to seeing, make your turn to Initiate the landing, which is the third letter to TWIT. It is time to get your flaps and wheels down if the wheels are retracted. (Shame on you if you did either of these things on that long base leg glide you were on.)

Talk

No second guessing at this point. It is time to congratulate yourself on getting from way up there to way down here without having done anything foolish, and you can already hear yourself telling a story about your successful off-field landing. Now that you are kicked back and gliding to final, it is a good time to call ATC, FSS, or perhaps your Maker, and let them know where they may find you, while you still have a little altitude left. You may have already done this earlier when you tuned your transponder to the emergency code, but it wouldn’t hurt to call in again, just to prove you can still talk without stuttering. I can speak here from experience — the last thing on your mind when your engine quits will be the radio. That’s why TWIT ends in Talk. You may be comfortable enough, or have enough presence of mind, to actually talk with someone other than yourself, once you have the field made.

Next time your engine gives up the ghost and you have already run through all the nasty words you can think of, try yelling TWIT to yourself. It may help you get down to terra firma safely.

By Jim Stark|2024-09-18T13:59:14-04:00July 18, 2023|Aircraft, Articles|Comments Off

Aircraft Oil: Go Ashless or Go to the Repair Shop

Any of you flying air-cooled aviation engines should be familiar with the phrase AD oil or Ashless Dispersant oil. These are special oils designed for aircraft engines and their use will help protect again pre-ignition and detonation. But what exactly does ashless mean?

Basically when you burn the oil, it will completely disappear and leave no significant ash behind. For non-ashless oils, most of the ash left behind when you burn the oil is from additives in the oil itself. Automotive and diesel engine oil designs for liquid cooled engines will contain a lot of additive that are is ashless and it’s not a problem in those types of engines because they don’t typically run hot enough to burn the oil.

Air-cooled aircraft engines are another story. In those engines, it is common for certain engine parts to reach temperatures at which the oil can burn. If a non-ashless oil was used, then deposits from the left-over ash could end up sticking to valves and ring lands. Those deposits could lead to hot-spots in the combustion chamber and those commonly cause pre-ignition.

The dispersant part of AD means there is additive present that is meant to hold solids in suspension so then can either be filtered out, or drain when the oil is being changes. If this additive is not present, it would be a lot easier for sludge to build-up in your engine during normal operation.

While the use of ashless oils won’t necessarily prevent all of the problems associated with pre-ignition and detonation, it is one easy way to help protect your engine from these dangers.

By Jim Stark|2024-09-18T14:04:07-04:00July 18, 2023|Aircraft, Articles|Comments Off

Fuel Contamination in Aircraft

Here in the northern latitudes autumn brings uncertainty about what to expect from the sky and wind each morning. Rain and overcast skies are frequent but counterbalanced by days when clear blue skies are accented with yellow sunlight that reflects the fall leaves and warms the spirit.

Those who fly in the winter months generally count the experience with mixed feelings. Cold toes and fingers are a certainty. So are hard-to-start engines and batteries that lack enthusiasm. But once the engine finally fires and the first BTUs of heat start filtering into the frosty cabin air, the whole experience can bring a smile to the face of the most determined pessimist.

The brakes may be stiff but they still work. Once you get to the run-up area, most of the breath-laden frost has cleared from the windscreen and you can stow the gloves. The sun streaming into the cabin does as much to warm things as the manifold heater. On lift-off, the rewards of winter flying come back to remind you why you do this in the first place. The prop bites the crisp air with authority. The dense air brings lift with a rush. Like the counter guy at the FBO said, “There’s a lot of lift going on out there today!” Indeed!

Understanding the gas

There are several reasons engines are hard to start in the cold. Parts are machined to operate easily in concert when they are at operating temperature. The further you get from that temperature—either hot or cold—the more interference there will be between interfacing parts. Poorer fitting parts increase internal engine friction.

Air-cooled aircraft engines typically run on SAE 50W oil when at operating temperature. Cold, the oil has the properties of molasses. The oil pump resists rotation. The oil resists being pushed around. The oil that starts out in the oil cooler may still be there when you land. If the surface air is cold, you know the air at altitude will be colder. It is not unusual to find the oil temperature at the bottom of the green arc, if it gets into the green at all. Pity the poor battery that has to coax all this reluctance into motion.

Mixture matters

Another reason cold engines are hard to start is the gas/air mixture is incorrect. The fuel system, whether carbureted or injected, is set up to operate at a given mixture for normal temperature operation, usually fifteen or sixteen parts air to one part gas. Cold cylinder walls condense gas from the mixture, causing the gas that’s left to become lean—far too lean to initiate normal combustion. Accordingly, engines of all types have an enrichment device to compensate when cold. For liquid-cooled land-based engines, a choke in the carb throat or an extra injector enriches the intake air. Both types of systems usually shut off automatically as the cylinder walls warm up, which usually doesn’t take long.

Air-cooled aircraft engines, on the other hand, have a primer. Even when carbureted, they won’t use chokes or have the acceleration pumps that are common for car and truck engines. Many aircraft engines that fire readily on zero or minimal prime on a sunny, warm day won’t even consider firing without prime in winter. If one squirt of prime works in July, it may take four to six in January.

If there is moisture in the first gasp of cold air that gets sucked into the cylinders, it can frost the plug electrodes. If this happens, no amount of priming or cranking (or swearing) will make any difference. The engine won’t fire until the frost is melted or otherwise eliminated.

Raw gas that condenses on the cold cylinder walls gets scraped down into the oil by the beveled oil control ring(s). It will mix perfectly with oil, so there is no good way to get it back out again unless you cook it out with heat and agitation (otherwise known as flying). If it is cold enough at the altitudes you fly, the gas from priming may still be in the oil when you land.

Problem or not?

But does gas in the oil really hurt anything? Hardly. It will cause a lower viscosity, but that may be an asset rather than a problem. There were WWII radial engines operating in the frozen north that were designed to inject gas into the oil before shutting down. The gas thinned the oil so that the engine could be cranked over in the morning with less resistance. After the engine got back to operating temperature, the oil returned to being an SAE 50 or 60W once the gas was distilled back out of the oil…sort of an automatic multi-weight oil before multi-weight oils were invented.

To say we find a lot of gas contamination in winter oil samples would be an understatement. We usually mention it because gas in the oil can show a fuel system problem. But that is rare in aircraft engines. We find a lot of moisture in winter oil samples too, and it goes into the same category as the fuel. Unless your aircraft engine is liquid-cooled, we don’t think the moisture is any more a problem than the gas.

When taking your sample, it’s ideal to have the oil warmed to operating temperature first, though if that’s not possible it’s best to just take the sample cold and not start the engine at all. Starting the engine but not flying it can introduce even more gas into the system. We realize an FBO mechanic won’t have the option of taking your airplane for a couple of turns around the pattern, even if he or she was qualified to do so, before draining the oil. Consequently, we turn up volatile gas and often moisture in your winter samples if you are flying in the cold. It only rarely points to a problem.

By Jim Stark|2024-09-18T14:04:47-04:00July 18, 2023|Aircraft, Articles|Comments Off