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Support, Remote Mount Oil Filter Kits, Frequently Asked Questions

How long should it take to install the oil filter kit on my airplane / helicopter?

Our classic response is " In our opinion, we don't think you can do anything to an airplane in less than 4 hrs." Seriously, although there is no reason to wait for your next annual, the most cost effective time is to install it is at your next oil change. You will already have to remove the cowling, make the mess, clean up the mess, check for leaks, and do the paperwork for your normal oil change anyway, so the additional time needed to install our filter kit at this time is minimal.

What makes your filter kit better than your competitors' spin-on filter?

Airwolf has spent over 40 years perfecting our filter kits. They have been installed on aircraft in one form or another since the early 1960's with never a service letter or an AD. We continually refine our system to make it extremely light, with the smallest footprint for the firewall. We actively pursue ways to remove every gram of unnecessary weight. Airwolf Filter Kits use special AN bulkhead fittings constructed with high quality Teflon washers and Viton O-Rings to give the installer unlimited options on how to route the hoses and clock the fittings. Every part is gold-anodized to eliminate corrosion so our filter kit will look as good in 50 years, as it does today. Airwolf Filter Kits are factory options on the complete line of Aviat Husky and Pitts airplanes, the Extra 300 Series airplanes, the entire line of American Champion Decathalon, Scout, Citabria aircraft, Maule Aircraft Company and Neico Aircraft's line of Lancair airplanes. In addition, every major aerobatic performer like the Aeroshell Team and Shawn Tucker use our filter kits exclusively. It might be better to ask our competitors none of their filter systems are offered as factory options on new aircraft.

Why don't hoses come in the filter kit?

We have always taken the position that no two airplanes are the same under the cowl, and therefore no two installations are the same. Too long of a hose, in many cases, is just as bad as too short of a hose. We simply detest including a cheap set of "do it yourself" hoses in the kit, just so you have something in the box. All of our hoses are made by an FAA certified hose facility, whose sole mission in life is to manufacture high quality TSO'd' aircraft hoses. We don't want you to ever worry about one of your hoses failing on your aircraft.

How long will it take to get the hoses once I order them?

We subcontract all of our hose building to a major hose manufacture. They are one of the largest supplies of hoses to the airlines and corporate airplanes and helicopters. They make a lifetime, Teflon, firesleeved hoses to the highest TSO-C53a Type D standard, and they do it fast. We have negotiated a huge volume discount from them and pass the savings on to you. If you call and place the order by 5:00 pm EST, they will make the hoses the same day and your hoses can be delivered to you as early as the next morning.

What does this fancy TSO-C53a Type D Specification mean to me?

It means that your hose is certified to withstand 2000 degrees Fahrenheit for 15 minutes. The objective is for you be able to make it to the ground safely, and not allow flammable fluids to accelerate the fire.

How do I measure aircraft hoses?

Aircraft hoses are measured from the tip of the flare at the end of the fitting, to the tip of the flare on the other fitting. The easiest way to determine the proper length is to install the filter on the firewall, and the adapter into the engine. Then, take any old hose, even a garden hose, and establish the most efficient routing to connect these two items allowing for engine torque and vibration per AC43-13. Your new hoses need to be built to exactly that flare to flare length.

Are the hoses really lifetime?

It is probably more correct to call the hoses "on condition" than lifetime. On condition, means that if the hoses are not cut or burnt, there is no reason to replace them. However, let's say that 8 or 10 years down the road, your mechanic says "I don't care what Airwolf says, I want these hoses retested." You can send all you hoses back to the hose shop, and for a nominal charge, they will run your hoses back through their test facility and recertify them and retag them with a new date tag. One additional point of interest; we try very hard to do everything in our power, to make flying safer. Most people do not realize that a typical 5 year rubber hose, is curing at the same temperature the engine is running at. This is why the hoses get so stiff over time which could fail, and why the manufacturer wants them replaced every five years. Going with a Teflon hose, which Airwolf uses exclusively, eliminates this need replace a hose purely due to calendar time.

Can I get all the hoses on my aircraft replaced with your Teflon Integrated hoses?

While we are not in the hose business per se, we will be more than happy to help you upgrade all your hoses to Teflon. Just call us with the part numbers off your old hoses, or give us the measurements and we will get them for you.

What do you think of these "super magnets" that attach to the outside of the oil filter?

First of all you have to realize, that there is very little ferrous metal in an aircraft engine. However if you wanted to collect what little there is, it really is not very effective trying to accomplish it at the oil filter location The oil is typically traveling at over 7-12 gal/min as it goes through the oil filter. These Neodymium "super magnets" as they are commonly called, are really not so super or strong enough to pull this ferrous metal out of suspension as it whizzes by at this velocity. It just isn't possible. In addition, most people don't realize that Neodymium magnets loose their magnetic properties the higher the temperature gets, where at 200°F they have but 10% of the magnetic forces left. Since your engine typically operates at 185°F, you can see the inefficiency of using a super magnet for this application. If you really wanted to put a magnet into your system, the ideal place would be the bottom of your drain plug. This way what little metal you may have suspended in your oil, is allowed to slowly fall out of suspension to the bottom of your oil pan, where it slowly migrates over to the lowest point in your sump, where it could be collected by a simple magnet, just like automobile engines have done for years.

While you're on the subject of magnets, what do you think of chip detectors?

The same principle applies as in the previous answer. The ideal location would be at the bottom of the sump, not in the oil filter as some might have you believe. And this assumes you really need a chip detector. Our company is an old time helicopter operator. We are very used to and like the chip detectors in our main rotor and tail rotor transmissions. However, we have lots of metal gears and bearings found in transmissions which are nothing like the internal parts found in a reciprocating engine. Again very little ferrous metal is in an aircraft engine. Put it this way, you could remove your drain plug out of your engine and see nothing but silver and know you have a problem, and nothing would ever show up on your super magnet or chip detector. In an aircraft engine it is a solution in search of a problem. In our opinion, this is an awful expensive option that does little good, except empty your wallet.

How often do you recommend I change my oil and filter?

Both Lycoming and Continental say that with the use of a full flow oil filter system, oil and filter changes can be extended from 25 hour to 50 hour intervals. We don't push this any more that we do what brand of oil to use as everyone has their own opinion. On one side we receive comments like "oil is the cheapest thing in this engine, and although I am glad I now have a filter on my airplane, I am still going to change it every 25 hours." On the other hand, we hear comments like "I am tired of throwing my oil away every 25 hours and I am installing this filter for the purpose of extending the work life." The reality is that there is really nothing wrong with the lubricity [slipperiness] of the oil at 25 hours. It's just so full of junk that the only way to get rid of the junk is to drain it all out and replace it. We see nothing wrong with extending oil changes to 50 hours and therefore agree with the manufacturer's recommendation.

What do you think of Spectrographic Oil Analysis Programs (SOAP) Tests?

SOAP tests are a great way of monitoring the trend of your engine wear. However, they are just that a trend, and one should not put to little or too much faith in them individually, but more so over the long term like every 100 hours or so. Put it this way, SOAP tests tell us about things we can't see. They only detect tiny parts per million (PPM) of different wear metals and abrasives that are less than 10 microns in size. So you could have large chunks of metal in your oil sample that will fall out of suspension before the SOAP test, giving you erroneous readings. Cutting the oil filter open each and every oil change, tells us about things we can see. There is no better way of monitoring the immediate health of your engine than by cutting the oil filter open. So both tests work together to provide you with the big picture of how healthy your engine is.

Does the screen stay in the system with the Airwolf Filter System installed?

No, the screen is history. All the filtration is accomplished inside the spin-on oil filter. To leave it in the system would require you to clean it every 25 hours and we don't want you to have to do that. Having said that, we do leave the screen in on radial engines. The reason we do, is all the major radial engine rebuilders asked us to leave it in as they see countless cases of things being dropped into the oil tanks that shouldn't be there and the screen is the first line of defense to prevent these foreign objects from getting into the engine oil pump and causing a big problem. We see no reason to inspect the screen other than at an annual inspection. Assuming there is clean oil in the tank clean, and we filter it right after it leaves the engine, you are not going to find anything in the screen anyway.

How tight should I tighten my filter to make sure it doesn't leak and is still easy to remove?

The single biggest mistake people make when installing an oil filter is failing to use a dab of Dow Corning DC4 or any good silicone grease on the oil filter O-Ring before screwing on the filter base. Never use engine oil on the gasket as 50 hours later when you try to remove the filter, the oil will have been long gone and the filter will not want to come off. We purposely made our oil filter adapter easily removable with 4 bolts, so if you put the filter on like a gorilla, or you used engine oil as a lube, you can take the filter base off the aircraft and put it in a vise and deal with it there. Never try to remove a stuck filter on the firewall, as our mount is deceptively simple, yet very strong, and you have the potential of pealing back the firewall with brute force. We purposely did not provide a way of holding our filter base with a large wrench because if would provide you with a very large lever and increase to potential of damaging the firewall. Again, fix the problem, not the symptom. Use a dab of DC4 silicon grease and you'll never have a problem removing an oil filter.

My Lycoming Engine is very close to the firewall, how do I know our kit will fit?

Our adapter on the back of the engine, is precisely the same length of your original 3-1/4" long oil screen housing. We could not change the length because it would effect the operation of your Vernatherm (oil cooler bypass valve). Our adapter will work in the tightest of conditions. In case you wanted to know a dimension of this distance, you need exactly 4.02" from the rear of the accessory case to the firewall for our kit to work and to have enough room for your oil temp probe. We realize that sometimes you might not know if our kit will work, until you have it in your hand, and it is this reason that all of our products come with and unconditional 30-day money back guarantee. If it won't fit...we can't image why not... just send it back for a full refund.

My Continental Engine is very close to the firewall, how do I know your kit will fit?

There is no problem with installing our filter kit on any O-200 - IO550 as the airplane usually has more than enough room for our filter kit to work. Where we see problems is in the A50-C90 series engines. It is not the fault of the engine, rather the airplane manufacturer has gone through great pains to push the engine as close to the firewall as he could, and it makes for a tight installation. Although 95% of the aircraft that have these engines which can use our adapter there are in fact, many aircraft where it just won't fit. You need exactly 3.5" from the rear of the accessory case to the firewall for our kit to work. The real problem is that we have to provide a way of getting the old oil temperature probe back into the oil loop, and it just takes space to do it. We realize that sometimes you might not know if our kit will work, until you have it in your hand, and it is this reason that all of our products come with and unconditional 30-day money back guarantee. If it won't fit, and we can't imagine why not, just send it back.

How much will your oil filter help reduce high oil temperatures?

Regardless of what engine you operate, the ideal temperature for the oil is 185°F. We want you to be as close to this number as possible. The first thing we need for you to do, is calibrate your oil temperature gauge to the numeric value of 185°F , so we have a starting point to work from. You can do this by purchasing a good thermometer, heating up some oil along with your oil temperature bulb, and seeing where 185°F is on YOUR gauge. A remote mounted oil filter will usually drop the oil temperatures about 20°F. Keep in mind that an oil filter is radiating heat, and only has so much surface area available. It is dependent on some airflow blowing on or around the oil filter, to carry away the heat. To gain maximum advantage of its cooling benefits, we recommend running a blast tube off the baffles and blow this cool air on the filter. If you want every ounce of cooling you can get, go to a salvage yard and buy the finned aluminum oil filter shroud that was used on the Piper Tomahawk aircraft. This will usually only get you an additional 5°F but anything you get will be free cooling.

What is your definition of "High" oil temperature?

On our website, we now have a new link that addresses this very subject, and specific things to look for. The first thing we do at Airwolf, is try to determine from the customer, what their definition "High Oil Temps" is. When we hear temperatures of 240-250°F, we get very, very concerned. I have been told that in Lycoming's service school, they tell the class that there is a temperature reading that you never, ever want to see on your gauge. Their comment is "AT 265°F, YOU HAVE TWO MINUTES TO LIVE" The temperature your read at your temperature gauge is actually 50°F lower that what the engine is seeing in the sump of the engine. Therefore at 315°F [265°F+50°F], you have no lubricity left in the oil. All you have is a liquid and engine seizure will occur.. Remember this the next time you climb out on a very hot day and your engine oil temps are at or very near the redline of your old non specific colored oil temp gauge. This is why it is so critical to calibrate your temperature gauge.

I own a Stearman with a radial engine. Do you make a kit for me?

Yes we do. We now have filter kits for most all the radial engines be it a Lycoming R680, Continental W670, Jacobs, or Pratt & Whitney R985. Pete Jones of AirRepair, one of the worlds foremost Stearman restorers, designed our Stearman kits and features them on their restorations. AirRepair recently purchased the Jacobs engine company and in fact is such a believer in our filter kits, that they will not warranty their overhauled engines unless it has one of our filter kits installed on it.

I have a Pratt & Whitney R1830 engine. Do you make a kit for me?

Yes we do.

I have a Curtiss Wright R1820 engine. Do you have a kit for me?

Yes we do.

I see your competitor advertises an oil filter for radial engines, that is capable of...

Question: I see your competitor advertises an oil filter for radial engines, that is capable of 20 gal/min. oil flows or 40 gal/min. oil flows using an off-the-shelf Champion Oil Filter in parallel, why don't you?

Answer: There are people in all industries, who really aren't very knowledgeable about the things they sell and promote. If the tall Champion filters are certified to and in fact can't handle a drop over 12 gals/min oil flow [ this is right in the FAA Filter Test Standards], why in the world would you try and shove 20 gals/min through it or even more hilarious, 40 gals/min through two of them? That's crazy. A radial engines uses thick, high viscosity oils which require extra large surface area inside the oil filter so that they do not collapse or go into bypass. A Champion filter is way, way to small to do this job. The only thing sillier would be to replace the Cuno screen on the engine, with a remote mounted oil screen. As we have stated numerous times before, screens have no dirt holding capability whatsoever.

Sky Tractor offers a filter kit for large radial engines, but it uses ...

Question: Sky Tractor offers a filter kit for large radial engines, but it uses this large 12" long Fram PH3335 oil filter. If bigger is better, why don't you use this large filter?

Answer: Bigger is not always better. The Fram NASCAR filter we use will handle 20 gals/min oil flows all day long. It was designed for the exacting and very expensive NASCAR engines. If you think we have expensive engines in airplanes, ask the price of a NASCAR engine. Anyway, after digging up some internal documents at Fram, we found that the PH3335 filter was designed for 10-20 gal/min flows. When we pressed Fram for why the big difference in oil flows, their reply was that this filter was designed for large diesel engines, with very thick oil, just like a radial engine, but at not very high flow rates, so this wide range was just fine. Well what might be fine for a truck, is not fine for an airplane engine. Since you never know how tight or fine the media will be in one of the replacement PH3335 filters, installing it on a large Pratt or Wright, might mean that the filter is bypassing inside. I know it is hard to believe with such a large filter, but it does happen. Also, many people don't have the room to put this huge filter on their airplane. There isn't that much room under the cowl. At Airwolf we do it right the first time. Our filters are neither under-engineered, nor over-engineered.

You seem to have filters for everything, what don't you have filter for?

Cars, trucks, tractors and turbine powered airplanes. Our saying is, if it burns avgas, we probably have an oil filter for you.

I have a Pratt & Whitney R1340 engine. Do you make a kit for me?

We now do. We are just releasing a filter kit for the large radial engines. The problem has been that the Champion CH48109 [the tall filter that we use in many of our filter kits] cannot handle more than 12 gal/min. oil flow, before it goes into bypass mode. These large radial engines typically develop from 12-18 gal minute oil flow rates. We have designed a completely new oil filter base that will utilize a Fram high performance [HP] racing filter, commonly found in NASCAR. We have designed it to mount to the engine mount for strength and ease of mounting as most firewall space in aircraft using these big radials is usually at a premium and mounting it onto the engine mount is a far better idea.