Alternative Oil Filter for Rotax

[dstclair]

Paul -- really enjoyed your seminar last night on "Care and Feeding of the Rotax 912".

You mentioned that an specific individual had done some research and testing and had found an automotive filter that matched the Rotax filter for the internal oil pressure relief valve. I'm guessing this is the K&N 1002? I'm showing my ignorance but why use a non-Rotax filter (even when out of warranty) for those of us that only change our oil a few times a year?

Are there other properties, other than cost, that make the other filter better?

[ct4me]

Aren't there potential warranty issues associated with using Non-Rotax filters? There is some lore out there about this issue, some of it caused by changes made in the Rotax filters a few years back. There was a change in the by-pass pressure valve, a check valve, and an anti drain-back membrane. For the minor difference in price, I can't see why anyone would want to take a chance.

[dstclair]

Tim -- Rotax certainly sets the rules for what they will cover under warranty but once that expires the owner may make different decisions. 5 year rubber replacement issue comes to mind.

I doubt I'd change filters for a few bucks but Paul mentioned it in his webinar and I was just curious.

[ct4me]

I know of cases where Rotax stepped up to the plate and covered significant repairs that were "out of warranty" on a pro-rated basis... but will likely only do it when logs are kept, records are meticulous... and spec'd parts are used.

[roger lee]

Okay, my favorite subject and soapbox.

I did extensive research years ago. There are certainly a few oil filters that fit the Rotax 912. They are ones that usually fit the Toyota truck. I have a list of about 8 filters. The Pure One used to be at the top of the list due to its particle filtering capabilities. Years ago before Rotax changed to the filter they have today I would have argued that a filter like the Pure One was even better, but that has all changed. Rotax made a few changes that the US auto or motorcycle filters do not have. I will state that the paper filter medium inside the Rotax filter is nothing special, but all our US oil filters have a by-pass pressure of 13-15 psi. Rotax used to be 14-16 psi. One psi wasn't a big deal and it isn't even that accurate and that's why you see the psi spread. This allowed too much unfiltered oil to by-pass. Rotax by-pass pressure is now 18-22 psi to stop that. US oil filters use a wet sump engine with the reservoir at the bottom of the engine. The Rotax is a dry sump and the oil tank is supposed to be mounted within special limits related to the engine. Many did not follow these specs. For instance Kitfox mounted their oil tanks way too high. With the old filters and the standard US auto filter this allowed for oil to siphon back down towards the cylinders and it did cause some engines to have hydra lock. One of the reasons we gurgle before start. The newer Rotax filter has a check valve in place to prevent that. Other people mounted the tanks too low. This siphoned the oil out of the engine. Rotax replaced the anti drain back membrane with a newer softer material to prevent that. The US auto filter membranes are too stiff.

Like anything else in life some people get away with things and some don't. As far as warranty Rotax can and does cover many things out of warranty. People have to mentally get past warranty considerations and think long term. For instance I know of someone that had a 912ULS with 833 hrs. and 6 years old. He lost the #1 exhaust lifter. Rotax stepped up and paid for the problem. The hardness coating decade. It would have been easily argued that the wrong and poor filter choice if it had not been a Rotax filter allowed particulates to by-pass that lead to this failure. The only thing that saved this person was he used all Rotax parts, documented such and had absolute good documentation since day one. This saved this person thousands of dollars all which may have been denied because he wanted to save a couple bucks on a filter. What a waste that would have been. If you have any failure Rotax and or the NTSB if involved will want a complete copy of your logbook. So crappy record keeping (even if barley legal), use of after market parts and poor maint. can and does bite people in the butt on a very regular basis.

Paul mentioned a few things in that seminar that weren't in line with research, test and 23 years of Rotax experience. One thing that comes to mind is his 100LL comments. If Paul spent some time at Rotax in Nassau and saw all the problems that people cause themselves he would probably change his opinion. Mechanics get paid good money to repair things that should have never happened.
I have seen many spend $2K-$6k to fix problems on the 912 and all because they listened to Joe next door with no or minimal training and trying to apply other engine technology to a Rotax.

I'll be the first in line to say it changed my mind and I used to argue a number of things. I have spent my time in Nassau and going back again this month, service 30+ LSA 912 equipped aircraft every year and have done numerous research projects. I will tell you the experimental guys have the highest overall engine cost over the life of the engine by a huge margin because of what is done or not done properly to their Rotax engine.


Smoking cigarettes won't kill you for a week, month or even a few years of smoking, but it will eventually. If you throw the dice long enough even a lucky winner will eventually lose.

Okay I'm off my soapbox. My finger tips are getting bloody.

[snaproll]

Paul -- really enjoyed your seminar last night on "Care and Feeding of the Rotax 912".

You mentioned that an specific individual had done some research and testing and had found an automotive filter that matched the Rotax filter for the internal oil pressure relief valve. I'm guessing this is the K&N 1002? I'm showing my ignorance but why use a non-Rotax filter (even when out of warranty) for those of us that only change our oil a few times a year?

Are there other properties, other than cost, that make the other filter better?

Rotax changed to a new filter with a supposed 18 PSI relief versus the 16 PSI relief on their old filter (from their published info). Just as their old/new fuel pumps, Rotax is using automotive parts, i.e.. a newer thicker spacer was required to adapt the new automotive fuel pump to function with the Rotax engine. I retired last year from a position where I routinely had pressure relief and pressure bypass systems tested and calibrated. I took two new Rotax filters for testing to verify Rotax’s claims and found the results did not match their claimed results. The first filter relieved/bypassed at 14 PSI, the second at 13.5 PSI. To be fair, the testing medium used was Aeroshell Sport 4+. Based on the test, I researched available filters and switched to the Tempest AA825706 filter which has the same relief/bypass rating, a higher burst pressure, and the ability to safety wire the filter after installation. Tempest is an old aircraft filter manufacture and has been used on Continentals and Lycoming’s for decades.. I am not concerned with warranty issues or politics, just safe operation and the ability to safety the filter is a plus, just like I have been able to safety wire filters for the last 50 years. I did not test nor consider the available automotive filters of which many Rotax owners have used for many years.
Link to Tempest http://www.tempestplus.com/PricesLiterature.aspx

[roger lee]

I wouldn't use a a Tempest or Champion. They were made for old and very different engine technology. Burst pressure shouldn't be an issue ever with our engine and safety wire should never be needed if the filter is installed properly. They don't have check valves and have the wrong anti drain back membrane. Using improper aftermarket parts keeps all the Rotax distributors and many mechanics in service and paid good money. I just made $10K in 2 weeks from people not following good maint. practices over the last few years. I like it. You may pay less in the short term, but most will pay more in the long term. If people don't make TBO or have premature failures they point a finger at Rotax, but you can almost always trace it back to poor maint. along the way.

Why ever roll the dice on a Rotax engine. If you don't like the small parts cost wait until you have to pay the big bucks because you wanted to save a couple of dollars along the way.

[snaproll]

I wouldn't use a a Tempest or Champion. They were made for old and very different engine technology. Burst pressure shouldn't be an issue ever with our engine and safety wire should never be needed if the filter is installed properly. They don't have check valves and have the wrong anti drain back membrane. Using improper aftermarket parts keeps all the Rotax distributors and many mechanics in service and paid good money. I just made $10K In a week from people not following good maint. practices over the last few years. I like it. You may pay less in the short term, but most will pay more in the long term. If people don't make TBO or have premature failures they point a finger at Rotax, but you can almost always trace it back to poor maint. along the way.

Why ever roll the dice on a Rotax engine. If you don't like the small parts cost wait until you have to pay the big bucks because you wanted to save a couple of dollars along the way.

Cost was not a factor as Tempest actually runs a couple dollars more. Suggest additional research on the Tempest filter - they are not "old technology". Appreciate the comments... Will consider the Rotax filter again when they meet the published Rotax specifications. VR.. Don

[roger lee]

Unless you can scientifically show it is a suitable filter like Rotax does with 23 years experience and millions of hours flight time and actual research anything would be hearsay. I have been there and done that with Rotax on a few subjects and just when I thought I knew what I was talking about they showed me all the other things I didn't know to form an educated response.

We think there is this much to know ................................
But there was really this much.......................................................................................................................................... and then we wish we hadn't gone there. We all tend to listen to Joe Blow next door or blunder down a not so informed path as we would like to think. I'll be the first in line to have fallen to that lack of total knowledge before myself. I have been there and know what that feels like. When I go back to Nassua to Rotax and get some one on one time I find out just how much I don't know and the why's things are the way they are. You may never get a lot of that in class.

I have learned the hard way sometimes; why test a proven system when it is usually just as easy to do it the recommended way. I work on more than 30 Rotax engines a year and get to see what everyone does to their engines. I have many pictures of many damaged engines. Why go there. Their bills for damaged engines tend to run into the thousands of dollars.

Have have researched Tempest and many others. I have cut them all open and talked to the engineers, not the salemen, that work at their facility. There are several oil and air filters made by one company and just branded differently for another company.

If money for a filter isn't the issue then why not use the recommended filter? We already know it is inferior because of the anti
drain-back membrane and lack of the check valve. If the old filters were working that were like some of our auto filters then why would Rotax make such a drastic change?

[MrMorden]

The safety wire thing seems a bit of a red herring to me. Has anybody ever heard of an oil filter unscrewing itself if it was correctly installed and snugged down? Once the oil pressure comes up and the filter seats, it's not going anywhere. Sure if you do it wrong it will fail, but that's true of anything...even safety wire.

When I change the oil after I seat the filter I always make two Sharpie marks, one on the filter edge and one on the engine in the same spot, and then check them after each flight for a few hours. They never change alignment.

[snaproll]

Appreciate the input and opinions. As the Mahle automotive filters sold by Rotax under the Rotax name are relieving at 14 PSI, is there another Rotax change coming that increases the relief to the 18 PSI they recommend? The anti drain-back membrane is standard on all Mahle automotive filters.

[roger lee]

They are supposed to already be at 18-22 psi. Anything less is news to me and I'll talk to Rotax when I see them in May.

[bitten192]

Interesting discussion. Since you brought it up in your webinar (which I enjoyed very much), WHAT SAY YOU PAUL?

[roger lee]

There were a few things that were more personal likes and dislikes and not current Rotax teachings. There are certainly a few things that can have personal preferences. Not everything new in the Rotax world comes out in writing so you can not rely on that alone. Revisions to manuals take quite a while so you can't rely on that. It is absolutely an ongoing discovery process from multiple sources. You have to go to classes or you will fall behind in new developments and changes from previous practices.

Rotax education is always ongoing and there is so much to learn it can take years and it takes years to see enough things to foster that learning. Even the top teachers for Rotax go back to the factory at times to learn new things. Just for the new 912is engine some have been back 4-5 times. I will tell you that to thoroughly learn about Rotax it takes a constant effort to obtain information from multiple sources and it takes many repeat Rotax classes and then you need to work on 20+ engines a year for about 5-8 years to get a really well round and complete education on the engines. The one reason it is constant with Rotax and not Cont. or Lycoming is Rotax has tried to better its engines and make new inroads to a better engine where the others quit many years ago. Going to 1-2 classes or working on 2-3 engines a year just won't cut it. I have to constantly keep up and hunt out information and it can change overnight. It has certainly been a time consuming and sometimes expensive schooling process. For instance I had to go back to Kodiak Labs (Rotax distributor for all the America's) in Nassau for 3-4 days last Sept. for a special class and I have to go back in May for a full week. All classes are out of pocket. The learning curve the first number of years should be straight up and if it isn't you are leaving things out.

Rotax supplies 85% of the worlds small aircraft engines.

[drseti]

Since you brought it up in your webinar (which I enjoyed very much),

Glad you enjoyed it, Ernie. Thanks for tuning in.

WHAT SAY YOU PAUL?

I thought you'd never ask.

I respect Don's engineering background and general knowledge, which is why I referenced him in the webinar. If he says the Tempest filter is a good choice, I have no reason to disagree. I also have the highest respect for Roger, from whom I've learned a lot, and fully appreciate his position on using only Rotax approved parts. My own stance is somewhere between these two extremes. Since my plane is in commercial service, I am under close scrutiny from multiple directions. Thus, I am compelled to use the Rotax filter, even though Don makes a good case for the Tempest being "equal or better" (the FAA's terminology for parts substitution). Nevertheless, if this were a personal aircraft not being used for hire, I would probably be less obsessive about parts sources.

Roger, with regards to mogas, I think you misunderstand my position. I fully agree that auto fuel is superior in the Rotax engine, for a number of reasons, and I am well aware that Rotax does authorize up to 10% ethanol. My issue is an airframe one. Evektor expressly prohibits ethanol, so I have no choice but to use 100LL.

Keep up the great discussions, gang. We all learn in the process.