Oil filter

[Curtis Brown]

Who sell the best oil filter for the C-145

[GAHorn]

Who sell the best oil filter for the C-145

I personally favor the http://www.fm-enterprises.com/ unit.

[zero.one.victor]

I bought the El Reno. Surprisingly enough,it's made by F&M. They're about the same thing,a while back George or somebody said the version sold by F&M has a different & better configuration where it seals against the accessory case.
Whichever you buy,be sure & ask to borrow a thread-chaser to clean out the threads in the accessory case where it attaches (where the oil screen is now). El Reno will loan you one for free. You want to get a good crush on the copper crush rings when you install the filter adapter. Double-check the depth that the adapter fits in the accessory case and make sure you get this good crush fit,or you'll have leaks (like I did).

Eric

[Dave Clark]

My plane came with the F&M when I bought it two years ago. The thread chaser apparantly was not used because it started to leak and I could not re-mount it and get the gaskets to crush enough. This happened right before I left with it last Summer and I had to remount a screen for the summer. I did the thread chase a few weeks ago and have finally gotten everything back together so that I could run it yesterday. No leaks and I could definately see a difference when I reinstalled it. That seemed strange because I really only needed to turn the thread chaser by hand and there was only a couple of slight resistance points. Another big problem with this setup is that you have to be very careful when removing the filter not to twist the assembly and break these seals. Definately do not over tighten the filter. I use a torque wrench and DC4 silicone on the gasket. Also be sure to re-direct the blast tube per the instructions. Mine wasn't and I had oil temp problems on warm days. Those went away when I used the screen because the blast tube was directed for that.

I was going to mount a filter on the bulkhead however I ended up putting a new intercom, spinner, tires, and other things that took $2000 at this annual so I decided to give the F&M one more try. I will not change filters until I get to AZ this fall (50-60) hours although I'll change oil midstream. I've not seen a spec of anything in the screen or prior filters in the 200 hours I've owned it so I think I'll not worry about it. My 2 cents is to buy a bulkhead model. If you want the F&M I have a buddy here who has one for sale for about $150 I think.

Dave

[GAHorn]

The reason the FM adaptors are better than the El Reno ones (FM indeed made them both, they just marketed them first thru El Reno and so....) is that El Reno may be selling you a design that has been superceded. Since FM is the actual mfr, you'll be more likely to get the later version, which does not suffer so much from leaks. (I.E., El Reno may be selling you a model that has been superceded. If you do have that superceded model, FM Enterprises will modify it for you if you send it back to them.)
The leaks were cured by a modification of a chamfered edge to the adaptor where it mates with the accessory case. This chamfer also necessitated a change in gasket material,.....the old "crush" copper/asbestos ring was discarded in favor of a fiber/cement gasket at the accy. case mating surface. In order for the fiber/cement gasket to properly work it must be accurately torqued,....which can only be done if the threads are clean. So that's the reason for making certain your threads are clean,...in order to get an accurate torque, ...not that clean threads don't leak.
(P.S. Are you sure you want to run clean oil thru a dirty filter? Without changing the filter you are also retaining about 1/2 quart of old oil in the system. Filters typically are about $10 from discount houses. I personally would rather dicard a filter without cutting it open than re-use an old one. If the oily mess of a filter-change offends you, try surrounding it with a zip-lock type plastic bag before unscrewing it. Use a rag to insulate your hands from the hot filter. When the filter comes loose, just seal the bag and toss it in the trash.
Be certain when using the FM/El Reno adaptors to use the correct filter. Do not substitute a 48109 or other model for the correct 48108. The other filters may not contain a bypass valve and the "109" is too long and will impart too much momentum to the adaptor and engine accy. case and possibly cause looseness, leaking and/or cracking.)

[N1478D]

It is as bad or worse to over tighten a crush washer, as it is to under tighten one. There are very exact specifics for tightening each size and type of crush washer. Most people tend to overtighten them which has a high potential of causing a leak.

[Curtis Brown]

Thanks for the info on the filter....
Now about my leaks. As you may recall I just completed and overhaul. Now have 28 hours on it and first oil change done. I seem to be leaking at the screen crush washer. However, we replaced all the crush washers. I am still getting a few drops of oil and it blows back and on to the newly painted white firewall. Could it be that the threads need chasing? Or God forbid the accessory case is leaking.

[n3833v]

I agree with George, change filters half way and not oil. Don't change oil and not the filter. I have much experience with extended oil changes on trucks. I would rather have good oil without the contaminants by changing more. I change at 25 hrs and still have the screens on the C-145.
John - n3833v

[zero.one.victor]

Dave,you say you had oil temp trouble on warm days with the filter. Said it was OK with the screen. Did you redirect the blast tubes after reinstalling the filter ,& did that cure the temp problem?
I did not redirect the blast tubes cuz I couldn't figure a clean way to do it. I tend to run high oil temp on warm days,but I did even before,with the screen. Never OVER redline,though sometimes right up against it.
Anybody do this blast tube mod for their filter installation?

Eric

[Dave Clark]

George John Eric et al...

You're probbly right but it seems to me that the filter should go an easy fifty hours. I guess I'll change the filter also and drag along my cutter.

Eric:

The instructions for the filter installation specifically states to redirect the blast tube. Last year when I went back to the screen for the summer I also did an AZ mod of opening the Cowl inlet above the filter for more air along the oil pan. So I don't know if it was that or the filter or the blast tube that caused the high temps the first year. I'll find out more when I get this thing back in the air. Redirecting the blast tube is not hard I'll give you hints. When we get to Stuart the first week in June you can come over and have a look and we'll talk.

Dave

[GAHorn]

I'll be very surprised if redirecting the blast tubes affects your oil temps. There's a common misundertanding about the blast tubes,...that says the tubes are only cooling the oil temp probe. But the blast tubes are actually blowing air upon the accy case housing where the oil pump is picking up the oil at the suction screen, and they are cooling the oil where it is most effective to be cooled,....immediately before being picked up and distributed throughout the engine. Just because an oil filter adaptor such as the FM-Enterprises (El Reno) is utilized, does not change the fact that the oil suction screen is still located where it always has been,...and the oil is picked up by the pump where it always has been. Leaving the tubes to cool that area is still apropo in my opinion.
I intalled the FM-Enterprises adaptor in accordance with it's STC instructions dated 10/26/98 and those instructions do not say a thing about redirecting the blast tubes. My oil temps have not changed one bit. Summertime in Texas still has my oil temps in the 220 range. I use 50 wt oil which allows a max oil temp of 240.

[Dave Clark]

The previous owner purchased from El Reno so the instructions I referred to are theirs. Interesting. I wonder if blasting on any area of mass from the temp sender forward wouldn't do about the same thing. The filter could also release a lot of heat. I suspect what really helped was opening the oil pan cowl intake. I also added hold downs last year for the rear of the baffle lids so they couldn't raise up and loose air.

Another thought is that by leaving the blast tube in the stock position you might not be sensing the temp at the pump/intake anymore so the reading could be false? In other words the intake oil is cooled well after the sensor when you leave it in the stock position and use the filter.

I also have a blast tube on the other side that goes to the lower part of the accy case. Is that one stock and what does it cool?

Dave

[Bill Venohr]

I installed a FM Enterprises oil filter in June 2000. The directions did not have you redirect the blast tube. My engine runs hot, to the point that when the outside temperature is 90 degrees or above I will probably exceed 240 degrees (running 50w oil). So I have to restrict my flying from those days. I've sealed a few small holes and gaps in the baffling and plan to replace the seals for the baffles at the intakes. I'm curious about increasing the air flow past the oil pan and any other suggestions.

[GAHorn]

There are two screens on the stock airplane, the suction screen and the pressure screen. They are located side by side at the lower rear of the engine accy. case. The oil pump sucks up oil through the coarse suction screen (looking forward, the smaller one on the lower left), pressurizes the oil with trochoid pump-gears, sends it through the pressure screen (the larger, fine-mesh screen on the lower right, the one we clean when we don't have an oil filter), and from there it flows through oil galleries to various parts of the engine.
The oil temp probe measures the oil temp inside the pressure-screen, which is at the last location available before that oil goes to work lubricating, cooling, and cleaning the engine. This suction/pressure screen area is the area cooled by the blast tubes. The intent is not to fool the temp probe, ...the intent is to cool the lower accy case where the oil is being handled prior to distribution,...and therefore that's also an appropriate place to measure it's temperature. This is known as the oil inlet area, because this is where the oil is inletted to the various engine working parts.
C145/O300 engines run hot generally because they are simple engines not normally equipped with oil cooling systems other than air-flow around the sumps. They run hotter still in 170's mainly due to poor cowling design. The original exhaust "fangs" stick through the lower cowl in a relative-wind high-pressure area, so ram air enters the lower cowling creating higher pressure and resistance that reduces the effectiveness of airflow from the oil sump cooling inlet just below the prop (above the air filter.)
Our engines were upward developments from the earlier "C" series which were low-output as far as heat was concerned. The C145/O300 engine is at the upper limit of thermal output without a cooler. The later GO-300 engine had oil coolers as standard equipment. (No, don't even think it, they are not the same.)
The answer for 170 owners is: Keep your engine baffles in good shape, run SAE 50 wt oil, which allows the red-line to go from 220F to 240F. If you ever have to replace your exhaust system, consider going to the Bartone or the Benham exhausts which will exit the lower cowl at the firewall and let you close the "fang" holes. (Meanwhile, check your "fang-holes" for the presence of the exhaust opening plate, PN 0552002-64, item 13, fig. 83A, if you have the later style cowling, originally installed on SN 26996 and on. My own airplane was subsequently fitted with this.) Don't worry about the oil sitting right at the red-line all the time. This engine does just fine and at least doesn't suffer from Swift-owner problems of too-cold oil (which contributes to internal corrosion. Swift's have updraft cooling so the sump gets all that cold inlet air before the cyl's heat it up.) Just don't extend oil changes needlessly because high-heat breaks the oil down and contributes to "coking". (The reason I believe our engines have a high valve sticking occurance.)
Meanwhile, look at the bright side of things. We have high oil temps, Lyc. owners have internally corroded hollow-cranks, bad oil-pump AD's, and spalled lifters and cams. Jacobs owners have vibrators with fouled plugs and leaks. Gypsy owners have 3 sets of wrenches, none of which actually fit anything on the engine. Ah,...aviation. Ain't it grand!

[Curtis Brown]

I called FM and order the filter $339 I think is what he said. He is sending the thread chaser also, but I may not need it with a freshly overhauled engine. I had the baffling rebuilt/repair/refurbished also placed baffling seal around the carb air intake and air intake above that for the oil pan. I have been running oil temps in the 180 to 200 range but the Mississippi heat has not sat in yet.