Oilmatic pre-oiler

[BigglesRV7A]

I have installed the oil-o-matic pre-oiler in my RV-7A and not with standing the short comings Mel mentions, I am still happy with the additional peace of mind that it gives me. In addition to providing positive oil pressure (~45psi) prior to engine start, it is also great for checking for leaks and priming the galleries and new oil filter after oil changes.

I work two weeks on two weeks off and hence the engine is left for up to three weeks at times without being used. I know I am conservative as in addition to using the pre-oiler, I also use a TANIS engine dehydrator after each flight and also have a REIFF preheater system. The experts tell us that most of the wear in our engine will occur in the first 10 minutes after we start it. Even more importantly, many engines don't make TBO because of internal corrosion issues. With all this information available, I spoke to Mahlon Russell (TCM) and based on his feedback elected to give my engine the very best chance of surviving both early wear issues and corrosion by using a 'belts and braces' approach. If I was using my plane regularly, some of these would be overkill though for my personal situation, I am happy to support longevity by using everything available to make it possible.

Cheers, Greg (IOF-360M1B, WW-200RV)

[Alschief]

Originally Posted by rodeja

Mel, thanks, but what are "Nye nozzles"? Just had the engine OH by Aerotec in Nova Scotia c/w the T mod. New style, wide lobe cam and tappets etc. I have 35 hr. on it now and am thinking of anything possible to make this engine last. Never even thought of the splash effect only on the cam - assumed that oil pressure would do the trick. Ron

RV9
C-FTJE

Unfortunately Chuck can not preform the Modification if the "T" Mod has been made.

[NickAir]

Pre-oiler or not your Lycoming Cam is at risk when non use is happening. An option I use all winter is noted, why, below:
Aircraft CamGuard
In aircraft engines, CamGuard is extremely beneficial for corrosion control when added to the crankcase of any infrequently used engine.

The presence of corrosion on the rubbing surfaces dramatically increase wear rates as the corrosion products are easily removed and often abrasive. In engines, corrosion manifests itself by causing material loss, surface property changes (pitting) and dimensional changes, dramatically increasing wear rates on critical steel components such as camshaft lobes, tappet surfaces and cylinder walls. It was this effect recognized by a major engine component re-conditioner that led to the development of CamGuard. Corrosion also attacks of non-ferrous metals and can damage bearings and bushings, degrade the efficiency of oil coolers and weaken structural components.

Engines have many parts found under such conditions including the interfaces of cam lobes and lifters, cylinders and piston rings and gears. Wear rates are determined by load pressures, relative speed, materials, surface properties and the lubricant. CamGuard anti-scuff and anti-wear chemistry protects engine components from startup to the highest possible temperatures.

[frankh]

Although this is somewhat off topic it seems the original question is prompted by the desire to make ones engine last to TBO.

IMHO most of the "not reaching TBO" issue is more to do with camshaft corrosion than lack of pre-lubing (even though I myself use an accumulator).

I hear a lot of folks suggest that internal corosion is due to outside humid air somehow getting inside the crankcase and corroding the cam.

IM (not so) HO this is nonsense. This about what happens when you burn fuel..it mostly makes CO2 and water vapour.

Some of this water vapour gets pushed past the rings and into the crankcase.

Now air is very good at holding moisture when it is hot. In fact air is capable of holding 3.75 times as much moisture at 90F than it is at 50F (thats as high as my Psychrometric chart goes)

So now imagine how much moisture can be held at say 180F?

So now your very expensive engine is shut down and it is full of almost saturated air at 180F..Now it cools to 50F overnight..what do you think happens to all that moisture.

Yup it condenses inside the engine a drips all over the cam..lovely!

So I built a single pass dehum system for about $50. The satisfaction of seeing a column of steam rise from the dipstick tube as the dehum system pumps air through after a flight is really priceless.

Cheers

Frank

[NickAir]

Frank, will you share your single pass dehum system? It sounds interesting and smart.

[guccidude1]

Guys: Getting rid of the moisture after engine shutdown is not so hard, just open the oil filler tube and watch the steam roll out. After 15 minutes, screw the cap back on the filler tube. For those more comfortable using "belts and suspenders" connect a small vacuum to the oil filler tube and vent all vapors, after a couple vacuum adjustments to keep from sucking crankshaft out. This is not rocket science but it works well. Dan

[NickAir]

Posting the oil filler tube opening after a flight to evac some moisture was a positive post Dan. Thanks

Seen this habit for years from pilots not in a hurry. Good type of guys to buy a plane from. They like the detail type work. I know, I am one too.

[frankh]

Originally Posted by NickAir

Frank, will you share your single pass dehum system? It sounds interesting and smart.

Really simple, most of the benefit I'm sure is to get the hot sweaty air out of the crankase before it cools and condenses. but this is cheap and foolproof so why not?

Take a 10ft length of 1.5" ABS pipe (Home depot) and 4 caps. Cut the 10ft length in half and glue a cap on each pipe. The top caps just get pushed on.

Take 4 1/4" brass hose barbed fittings with 1/8th pipe theads on the other end.

Drill holes in the plastic caps mentioned above and self tap a fitting into each cap.

Fill tubes with desicant from harbor freight...buy two 5lb bags ($5 each) and fill ABS pipe and replace caps..You now have two columns.

Buy a PETCO own brand aquarium pump ($15) ..they are blue/grey and pretty large..

Connect output of pump to the bottom of first colum..out of the top and into bottom of second column..out of top and into the breather hose on your engine. All this with flex PVC tube.

turn on pump and very dry air will ventilate through crankcase.

After 6 weeks or so (western oregon) the blue desicant will turn pink, so I take it home (I have a little spare I put in the columns which is good for a week) and bake in the oven at 300F for 5 to 6 hours to trun it blue again.

Thats baically it..I have a little clear tube on the discharge of the second column with an ounce of dessicant so i can see when its time to recharge..I.e when that tuns pink..all of it is pink.

Frank

[Gash]

Frank,
I would like to build the dehumidifier setup you described above. Do you have any photos that you could provide? Thanks very much!