Quick release oil drain on front engine.

[Richard]

Does anyone have a quick release oil drain on the front engine? I've heard that they would hit the nose gear. Are the quick drains out there really that long?

[WebMaster]

Good morning, Richard.

GMAS talked about this at TC. :) When the nose wheel retracts, there is a very small space between the bottom of the engine and the wheel. Putting a quick drain on the front engine will practically guarantee that the drain will hit the tire...... With vibration, you'll end up with a hole in the sidewall, a bad thing.

[Richard]

Well. That's no good. What I would like to do is put a bypass filter on both engines. This is plan (A). However, because of certain agencies (that we need not mention here) the prospects of doing such is limited at best. Therefore, we have plan (B). A portable machine set up with bypass filters on it. After every flight I could plug the engines into it. The benifit of such a setup is clear. The oil would stay almost as clean as a fresh oil change every day. The challenge is:

We know where the oil is going back into the engine. The filler on the engine. What we don't know it where it's going to come out. The rear engine is a no brainer, but what to do about the front? Any ideas?

There was a 170 that got field approval of a bypass filter in Alaska. Can this information be used?

Richard

[SkyKing]

Richard,

Larry forgot to mention the FIRST thing that would happen if you installed an oil quick drain on the front engine of a 337: the first gear retraction would push the quick-drain open and all the oil would be lost, and then moments later you'd have a seized engine and failure of the powerplant. Don't even THINK about putting a quick drain on the front engine, irrespective of size.

Now, I'm trying to decipher what it is you're trying to accomplish with the "oil by-pass," as you refer to it. The full-flow oil filters on these engines do a great job of keeping the oil free of things that aren't suppose to be circulating... although if you have a turbo version and the engine is getting along in time and years, it's more than likely your oil will start turning dark a lot quicker do to combustion products and carbon. This will especially be the case if your airplane has been sitting a lot, short hops, and then you run it more often and harder... presto... sludge and carbon build-up.

Our '77 P-model suffered from this scenario, and of course as P337 operators know, it is unfiltered sump oil that feeds the wastegate actuator valve, and the restrictor/orifice at the inlet sometimes gets plugged with carbon debri making for slow turbo spool. To help clean out the system when we began flying it more frequently than the previous owner, we added some Rislone which helped removed most of the sludge and also helped the upper end. You might also have to back-flush the wastegate to clean the restrictor and restore normal turbo operation.

Our bird has about 1250 on the front and we're changing the oil out at 20-25 hours, but you shouldn't be too concerned if the oil is turning darker quicker -- especially if your airplane's been setting... the darkened oil is proof positive that the detergent action of the oil is doing its proper job. And when you cut the filters open you'll find they're doing a good job of catching most of the carbon chips and flakes.

SkyKing

[Mark Hislop]

Richard:

I'm not sure exactly what you mean by the bypass filter. If I interpret your post correctly, what you are trying to do is to refilter your oil to keep it clean. I have installed this type of filtering system in industrial hydraulic systems before, and it does do a good job of keeping very small particles (under 10 microns) our of the system.

However, I'm not sure how valuable this system would be on aircraft engines. Hydraulic systems and engine lubrication are two different animals. I think that the critical items in engine oil, particularly on aircraft engines, is the lubricating quality and chemical composition. Aircraft engines, particularly those that are not flown often, build up acid content due to moisture condensation. Also, many of the polymer chains that provide lubrication qualities break down. This is why it is recommended that you change your oil every 50 hours or 6 months.

I think The combustion particles that the oil captures are of little detriment to engine lubrication or wear. I'm not sure if the extra filtering would accomplish much, since you would still have to (or at least should) change your oil.

On the other hand, I may have completely misunderstood the system you are talking about. Could you elaborate? Thanks.

Mark

[Richard]

Mark. I think you've got it pretty close. Talking with the various manufactures of the filter systems state that the chemical makeup of the oil is left intact. I am interested in filtering out all the combusion particles because of sludge acumulation and keeping the turbo components as clean as possible.

I run bypass setups on my trucks. Wow, what a differance. Oil is perfectly clean. What I would like to do is maybe a waste of time and resources? It just sounds good if the oil was clean all the time. Yes? I really know very little about chemical engineering and oil makeup. I'm just the common guy looking for something to insure my expensive engines last as long as possible.

If it would be good to pursue, where could I draw the oil out of? Dipstick is all I can think of if the quick valve can't be used.

Thank you for your help.

Richard

[Mark Hislop]

Richard:

Personally, I think you wouldn't get much benefit out of filtering the combustion particulates out of your oil. You state that the bypass system will not affect the chemistry of the oil, which is true. The problem is that you already have acids in your oil, and the bypass filter won't change that. Also, if the oil has broken down, the bypass system won't help that either. I'm certainly no expert, but I think that the particulate matter is inconsequential. This is often not the case with hydraulic systems, where clearances are very tight.

I suspect your truck engines are a different matter, since they are liquid cooled, and tend to operate at a steady temperature. That should reduce the amount of moisture held in the oil, and the resultant acidity. I would guess that oil tends to last much longer in those engines, to the point where combustion particulates could build up and become an issue.

If you were to try this system, I'm not sure where you would tap into the engine for the oil pickup. A clue might be found in the "preoiler" products. They have to do the same thing, but I'm not sure how they do it.

Let us know what you decide to do. It is an interesting concept.

Mark

[GMAs]

Yep... some bad and some good... but, this ain't no truck... and its has parts and pieces that are really not likeing each other to begin with...

These are the facts of oil... your not the first to try and keep it clean and save it... for reuse...

the problem is that the other stuff in oil that wears out... like the aditives... which protect your engine... go away... after time.. that is why they want the oil changed on a time or use interval... no filter will bring them back... nor will the filter take the other stuff out...

Aircraft engines are kinda funny ducks.. they work at a higher temp... and yess the water does go away... by boiling off.. but, the sulfer oxides and silicon products stay... your truck uses a parifin based oil... we use ashless... so it won't gum up the insides... as you can't afford to have that happen... so our oil is more detergent orenented... and while it is working it tries to keep the particles from damaging the other parts by electrochemical contact ... for a better use of words... but, the heat does something else... it keeps on building up acids... and that the filter would not be able to take out...

So just because the oil looks clean... it has bad things in it that will hurt mag, alu and steel parts.. that we don't want hurt... the best way to long engine life... change the oil... get new wetting agents, soaps and detergents into it... and get the old acids out.... besides... by the time you finish buying this system... we can buy lots of oil..... as them filter do wear out... and need replacement too...

Nope been their done that... best filter system on a plane is one that goes to 10 microns and stays their... can you imagine the 50 wt oil at 40 deg trying to go thru this bypass filter.. ???... at 100 lbs of oil pressure.. it will make it into something that the manufacture didn't have in mind.... crushing just about anything...

Then their is the libility thing... check and see if they will back you on your application... bet they won't... smile.. matter of fact they probably will tell you to go get lost... as they want nothing to do with the avation industry or owners... and warn you not to use their product on a aircraft engine... yep... been their too....

Actually the screen is about all that you can use... with spin on filters coming along a little later... but, hey here is one.... for you... why not get all the metal particles trapped in the filter... by using magnets.... some actually think the metal particles are the bad guys in oil... and not the dirt... after all your up at altitude and their isn't much dirt... up their... so its got to be the metal particles that are wearing out the parts... smile... big magnets on the oil filter are the answer... or course the compass will always point north at the oil can... smile....

Its a good idea.. just not practicle and clean oil is in the form of new... for aircraft... if it were clean all the time... we wouldn't know what was breaking when we did the oil analysis... etc... but, thanks for the though tho... and the next time you do your annual... take both engine cowlings off the front... and watch the wheel come up under the pan... ya its real close... I have seen the safety wire when done wrong... cut the side of the tire... renerdering it damaged byond use...

So the others... watch the safety wire up their on the pan nut... make sure it goes on the side with the little bend back... not on the bottom... nothing should be lowere than the flat on the pan nut... just a rule... smile... GMAs

[Richard]

GMAs, you seem to know your stuff. Thank you for your time, and insight. At this point I really don't know what to pursue. The manufacture of Oilguard is interested in looking into the aviation industry. They seemed very nice, and gave me some direction for using their products on planes. They wouldn't put it in writing of course.

You are right about one thing. 50wt oil when cold would be high pressure. Too many little things I didn't think about. A once simple idea is now not so simple.

Cessna really made it tight in there. I wonder what drain solution is out there for the front engine. Maybe a large funnel with a screen in it to catch the plug and a metal drain tube with feet and some type of container?

Is there a way to prelube the oil system before starting the engine?

We are installing the new front engine this weekend. Lots of details. Seems like a simple engine, but has so many little parts and pieces. The IA that is working on it says that Skymasters are the most bodged together planes he's seen. Lots of backwood repairs. This plane was no exception. Lots of tractor parts. Saftey wired the baffles on instead of springs. Automotive bolts where all the expensive bolts went. (Of course most of them look like they were failing) Had every bolt on the torque links starting to shear, all because they weren't the right hardware. My hat is off the AP's and IA's out there. They really do a great job. It's much harder to be a aircraft mechanic than automotive. No comparison. The level of knowledge that AP's have over automotive mechanics is impressive. I appreciate you experianced guys answering my questions. Here in my area we have no AP's, IA's or repair shops. I have to import mine from 300 miles away. So your advice is of real value to me. Thanks again.

[Kevin McDole]

Richard,

For preoilers, checkout www.oilamatic.com. I have no experience with this product, but it seems to me that the cam is the part that'll get damaged during a dry start. And since the cam gets lubricated by splash, the preoiler isn't going to do much. There's no substitute for regularly flying the airplane. Just my opinion ...

[SkyKing]

Richard,

Here's how we do the 'drain-thing' for the front engine on the Skymaster. You don't need a funnel or anything fancy. Just find yourself a wooden block, say 6 X 6, or 8 X 8, that's almost the same height as the nose wheel tire... then place one of those 30-lb square plastic laundry detergent buckets on top. The blue ones that Albertson's (Good Day Brand) carry (blue color plastic) fit perfectly across the width of the internal wheel well opening, and they have a couple of grooves in the top part that will slide neatly onto the side-lip of the wheel well for additional support.

What we do first before positioning the wooden block and the bucket, is to cut and remove the safety wire, then loosen the plug with a socket wrench. With the wooden block positioned against the nose wheel tire and the laundry bucket on top, centered under the drain plug, there's still plenty of room to get your hand up to unscrew the plug using a latex rubber glove and/or paper towel. The paper towel is needed because the plug will be too HOT to handle barehanded and it will also shield your hand from the hot oil should you fumble the plug.

The trick to keep from losing the drain plug in the bucket is to very carefully unscrew the plug with a couple of paper towels folded over the cap until you can just feel that it's free, then quickly pull it away using a side motion. The first time you do this you'll probably splash some oil on yourself, but practice makes perfect!

Oh, and when you re-safety the drain plug... make sure that the safety wire is knurled under and is tucked away from the plug so that it won't gouge the nose wheel on retraction... things are a close fit.

SkyKing

[GMAs]

Yep I will have to send you the drawing on how to make a oil drain for the front engine... its real simple... we used to use the bucket trick like skyking says... but, then we got to where we wanted to catch all the oil and stuff we wash the engines down with... also... to be enviromentally correct... we came up with a pan tray thing that has a tank on the bottom to catch all the stuff... It slips right around the strut and gives you plent of room to get to the pan nut... all the oil drains into a bucket on the side... and we clean it up when we wash down the engine also... works great...

Ya cessna and cont engine could have done like the beach does.. and put the oil drain off to one side... so that you could get a hose on it like the rear one can... but, nope they had to do it their way... smile... GMAS

[Keven]

Is there a reason that you can't use a pump with a fitting that goes in the dipstick hole to draw oil out similar to those used on boats?

Keven
________
The Cigar Boss (http://thecigarboss.com/)

[Bob Cook]

re oil change

You do not get all the "scum" and metal filings etc. off the bottom of the crankcase when you use the "super sucker" method. This was a trick years ago in Europe for quick oil changes but never worked out.

Keven;
Had an enjoyable lunch with Ed at Silva City on Sunday. Sure is a "quiet airport".

Bob