In the July 5 print issue of General Aviation News, reader Dennis Reiley offered his thoughts in Letters to the Editor about my column, “Does my engine need an oil filter?”
Here’s a bit of what he had to say: “I have to disagree with Paul. Every internal combustion engine needs an oil filter — even those that have frequent oil changes. An oil filter can mean the difference between getting to your destination safely and experiencing a catastrophic engine failure.”
First, I wouldn’t say Dennis is disagreeing with me, because I understand exactly where he’s coming from. Besides that, I agree with him, but there are other factors that come into play as to whether an engine is equipped with a full flow oil filter or not.
Let’s look at some of the scenarios that lead to the decision whether an engine gets an oil filter or not.
During my years with Lycoming, I held various positions and at one time I was in original equipment manufacturer (OEM) sales. These accounts were made up of companies like Cessna, Piper, Bell Helicopter, Mooney, Aero Commander, Beech Aircraft, Hughes Aircraft, etc. Each of these companies would come to Lycoming and tell us that they required an engine with so many horsepower, not weighing more than X pounds, etc.
We would gather all the engineering data covering the various engines and come up with something in the range they were requesting. Then, the pricing for a specific configuration would begin, which can be a rather extensive program, assisting them in their choice of fuel systems such as carburetors, fuel injector, magnetos, starters, etc. Each one of these items, depending on their choice, impacts the overall cost of the engine.
I can give you an excellent example that still is very vivid in my old mind. An OEM customer wanted to buy a simple O-320 series engine and they had really done their homework when it came to pricing. We had quoted the price for the engine, which included an oil filter. As it turned out, that price exceeded what they were willing to pay by just a few dollars, so they declined to purchase it.
They requested that Lycoming review the entire engine quote and make an attempt to reduce the overall cost that would fall within their price range. When we reviewed the package, we simply removed the oil filter, reverting to the oil pressure screen and housing and reduced the engine price to the point where they accepted it and the contract was signed for hundreds of engines of that specific model.
I guess we have to look at the big picture here and decide whether the airframe manufacture was seriously attempting to keep the cost of flying down, which we all know this is what we manufacturers get severely beat over the head for all the time, or was he failing to offer a better product by including the oil filter?
As the good old boys say, “it’s them that’s got the money who make the rules” and this is a good example of what we’re talking about here.
Even to this day, the pilot who bought one of the aircraft with one of these engines may install a full flow oil filter kit. He’ll also pay a lot more money for it than the OEM would have had it been installed originally, but the OEM doesn’t really concern themselves with that now, because their original intent was to start off with an engine price that met their requirements. This may sound a bit cruel, but we’ve got to face facts folks, and this is how things go in the real world.
Just stop and think about this for a moment. Any and all manufacturers will give you exactly what you want — a good example would be buying a new car. There are many items that are standard today like an automatic transmission, but I remember the days when if you wanted an automatic transmission, you paid extra for it. If you wanted heated seats, you paid extra, etc.
Automobile manufactures continue to offer stripped down models of cars and trucks, but the buying public demands more amenities and believe me, they pay extra for them.
Remember another old saying: “If you want to dance, you’ve got to pay the fiddler.”
It all boils down to the fact that you can have almost anything you want on your engine, but you gotta pay!
Oh, I almost forgot — there is one more very important reason that an oil filter may not be installed on an engine. It requires a certain amount of space between the accessory housing and the firewall of the aircraft.
Most GA aircraft have the luxury of having that space, but not all do, especially some of the smaller homebuilt and kit-built aircraft. In recent years the industry has conquered that problem by introducing remote oil filters. This is ideal for most installations, but it still boils down to a money issue as to whether you think it’s a good investment for you and your aircraft.
I guess I’ve just about beaten this subject to death, but Dennis there is one more very important point I’d like to make if I may.
During my years at Lycoming I traveled worldwide and I made it a habit that when I visited an aircraft maintenance facility, I’d ask the director of maintenance where they put their drain oil. The response was pretty much standard that it would be in one of the rear corners of the hangar. I’d stroll that way and check out the drain pan and guess what I’d find at probably 50% or better of the facilities? There, in the drain pan would be three or four — and sometimes more — oil filters that had not been cut open and inspected.
This brings me to your statement “An oil filter can mean the difference between getting to your destination safely and experiencing a catastrophic engine failure.” How could this be if we experienced what I mentioned above?
The other thing that comes to mind is the fact that when the maintenance event is signed off in the logbook, you are stating that you complied with all FAA requirements, etc., so if the maintenance failed to remove and inspect the screen or cut open the oil filter, then in my opinion, that was in violation of the FAA requirements, which states something to the effect that you must remove, inspect and clean all screens and filters.
Dennis, I hope I’ve added something to this subject that will help you understand why not every engine doesn’t come standard with a full flow oil filter.
I do appreciate you taking your time to let us know your thoughts, and I’m certain others now have learned something regarding this subject thanks to you.
It would seem to me that after all these years there doesn’t seem to be any conclusive proof that not having an oil filter was detrimental to the engine; accordingly, one must only assume that it doesn’t matter. What really matters is that the FAA drop the third class medical – pronto – and that’s because there is definetly conclusive evidence that the third class medical doesn’t reasonably contribute to safety.
Having a full flow oil filter should be a FAA requirement along with a mandentory filter inspection, and should be a requirement of the insurance companies. It is not a question of if , it is when the failure shows up. In effect the best way to be ahead of your engine maintenance requirements.
You really think we need move government intrusion for something that is of only a small benefit to the longevity of an engine??? Lack of a full flow oil filter will not cause sudden failure of an engine, but instead under some conditions *may* allow accelerated wear of bottom end components such as bearings and cam. Please feel free to move to a country where the government micromanages every detail of aviation. I’d rather that not happen here.
As an A&P/IA It is my opinion that a “catastrophic engine failure” will seldom be prevented by a filter. The filter removes particulates that are the failure it does not prevent it, they will slow the wear rate by removing those particles. If the aircraft was not designed for the filter there may well be space or clearance problems with a add-on filter,even remote mounted. Aircraft engines with out filters do have high pressure screens that will easily catch any particle large enough to cause catastrophic damage in a few flights. Adding more things behind the engine can change the airflow and effect cooling of the engine or accessories as well increasing the chances for failure. I have seen magneto blast tubes cut ( causing high mag. temp.) to make room for add on “safety” items such as oil filters and stand-by vacuum pumps as well as things such as large air oil separators. Corrosion is the big danger to engines and a filter will not help prevent that. Changing oil at six months and using a preservative oil like Phillips anti-rust or adding Cam-Guard will. If you want a filter by all means get one, but be sure the installation does not case clearance or cooling problems if your firewall forward was not designed to have space for a filter.
Interesting article, but the one thing you failed to address is whether an oil filter vs an oil screen helps prevent wear. I *think* the answer is obvious and that is really what the discussion should be centered around. Is it more cost effective to install a spin on oil filter vs more frequent oil changes? And, are you likely to get more hours out of an engine using a full flow oil filter vs an oil screen with more frequent oil changes?
In the 60s, aircraft engines were relatively inexpensive to overhaul compared to today where an overhaul has become a major excursion in getting to know your local banker. The manufacturer that wouldn’t pay for filters, effectively just pushed the cost off onto the end user. Penny wise and pound foolish. In 1960 that may have made sense. In 2014, it doesn’t. When was the last time you saw an automobile manufacturer offer a vehicle without a full flow oil filter? I’m thinking late 50s or early 60s?
In today’s world, general aviation is the only segment in the world still using leaded fuel. In the case of many light GA aircraft, the FAA forced us to overload the engines with lead. Lead is great as an octane booster, but creates a lot of particulates in the engine that significantly increase wear. A full flow oil filter is part of the protection from that. As you pointed out in an earlier piece, with only an oil screen you can also help prevent excessive wear with shorter interval oil changes. Many of the small Continentals are operated that way in order to avoid the additional weight of an oil filter assembly and the fact that there aren’t any really clean oil filter installations for the A series engines. But with the cost of engines today, why not add the protection of a full flow oil filter to the package if it is cost effective to do?
On that engine quote proposal, how much was a few dollars? I still stand on my opinion that anyone who operates any engine without an oil filter is going to be spending far more in extra maintenance than having an oil filter would cost them. So unless the oil filter assembly is grossly overpriced choosing an engine without an oil filter is a serious error in judgment.