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-   -   An easy oil circulator for stored engines. Engine pickling (https://vansairforce.net/community/showthread.php?t=174551)

Hartstoc 08-22-2019 12:15 PM

An easy oil circulator for stored engines. Engine pickling
 

With my RV down for major mods for almost a full year, I began looking for ways to protect the engine. I discovered these auxilliary oil cooler boost pumps for auto racers at summit racing:

https://www.summitracing.com/parts/til-40-525

I used inexpensive hardware store fittings and hoses to create a loop drawing oil from the second oil drain and force feeding it anywhere on the oil cooler loop, it does not matter what position the vernatherm is in. The gauge on the bottom reads output pressure from the aux pump, and the one on top is connected to the usual oil pressure tap. As you can see, it maintains about 40 PSI for as long as ypu want it to flow. Spinning the engine with plugs removed kicks the pressure up about 10PSI at the oil cooler circuit and abput 8 PSI through the oil channels. You can recirculate oil as long and as often ad you like as frequently as you care to. If I was storing overwinter in a cold climate I’d set this up each year. I”ll let the photos tell the story.- Otis:













DanH 08-22-2019 12:50 PM

Otis, what parts do you hope to preserve with circulation?

bkthomps 08-22-2019 02:27 PM

another idea is to fill it completely with oil, and drain when you want to run it

ATF or oil in the cylinders, cap with junk plugs

no room for air, no room for corrosion

RONSIM 08-22-2019 03:18 PM

Not sure if the cam is protected -- Lycoming
 
recommends about 1000rpm to "splash" lube the cam/followers -- not sure spinning the engine with the starter will accomplish this.

Good piece of work on the setup, though.

Ron

Hartstoc 08-22-2019 07:00 PM

Quote:

Originally Posted by DanH (Post 1368538)
Otis, what parts do you hope to preserve with circulation?

Well, with substantial flow from the electric pump combined with another 8-10 psi running the starter with plugs out, I definitely gpt a reall good coating of all cyl walls and rings, all of the gears in the accessory case thoroughly coated with oil, and possibly some splash on the cam as well. I’m dearly tempted to pull one jug just to see if this might be true. Keeping 12qts fresh clean oil in the cc, and also keeping dessicant bag inside the accessory case when sitting.

The EarthX ECT900 certainly gave it a pretty good spin. I’m not sure where the 1000RPM for cam splash came from, would depend on numerous factors thus I’m tempted to explore. Loath to pull a jug, of course, but it would be interesting(and I’d have a chance to squirt some oil around in there if the cam was indeed dry.x Otis

BillL 08-22-2019 08:15 PM

Hey Otis, why not just use some VCI additive?

It releases volatile ingredient that maintains a plating action inside the engine. The hot link may lead to a source.

Also, a desiccant will/can help by keeping out any moisture that will create ions and corrosion.

I do like the system though, and it could be used as a super filter in a kidney loop to clean the oil when the engine is not being used. A 3 or 5 micron filter would do that, and/or a centrifugal filter that would remove all the suspended lead greatly extending oil changes. Probably too much trouble, but it would tecnically work.

Toobuilder 08-23-2019 10:11 AM

Just keep in mind that keeping oil "on" the cam is different than creating the hydrodynamic wedge of oil that keeps the lifters "off" the lobes of the cam. One is an anti corrosion technique and the other is an operational requirement that is only met with the engine RUNNING. Turning the prop by hand or starter results in metal to metal contact and the cam dies a little with every revolution.

Hartstoc 08-23-2019 05:33 PM

Quote:

Originally Posted by Toobuilder (Post 1368717)
Just keep in mind that keeping oil "on" the cam is different than creating the hydrodynamic wedge of oil that keeps the lifters "off" the lobes of the cam. One is an anti corrosion technique and the other is an operational requirement that is only met with the engine RUNNING. Turning the prop by hand or starter results in metal to metal contact and the cam dies a little with every revolution.

The cam is certainly the crux issue here, but I’m pretty sure that if you could know for sure that a cam lobe is wet with oil, the film strength of the oil is adequate to prevent unlubricated metal to metal contact that would produce any significant wear during cranking by hand or starter. But how can you know? Aye, there’s the rub!

I guess one safe and fairly easy approach might be to remove all of the push rods so no such harm could be done. (Oh, wait, I guess maybe Lycoming hydraulic lifers may not be constrained at max inflation by circlips, so oil pressure would force the lifter body against the cam lobe in the absence of a pushrod. If so, scratch that idea. Can anyone confirm?)
- Otis

maniago 08-23-2019 06:32 PM

This is pretty good Otis. Kinda wished youd crunched your photos first, but its good. Not sure I quite get where you plumbed the pressure oil back into the system such that it doesnt push the oil backwards thru the passages.

To alay some fears, any rotation speed that will cause the oil to be flicked off a surface will suffice for oiling the cams. Starting rpms are plenty for this. Consider that the crank weights are revolving thru the oil in sump AND oil is spurting out of all the bearing surfaces - cam and crank. Its going everywhere, and the crank whips it into a massive oil fog right quick. Theres no need to worry about this. As far as the oil barrier being retained on the cam, that also is not a function of rpm at the slow speeds we run. The barrier will remain for a few cam revolutions without replenishment from the splash and fog. After that the starting rpms are enough to create the necessary splashing and fogging.

Not sure you believe that? Consider that if this wasnt the case, Lycoming, Conny (and any engine mfg for that matter) would tell us that if the engine doesnt start in one or two blades, stop, pull the engine and rebuild it cause its self destructed. But alas, we know thats not the case. Witness your hangar mate flogging his motor with a flooded or painfully long hot start.

chaskuss 08-23-2019 07:41 PM

Quote:

Originally Posted by Hartstoc (Post 1368820)
snipped (Oh, wait, I guess maybe Lycoming hydraulic lifers may not be constrained at max inflation by circlips, so oil pressure would force the lifter body against the cam lobe in the absence of a pushrod. If so, scratch that idea. Can anyone confirm?)
- Otis

No, that can not happen. The one fool proof way to protect the engine is to remove the push rods and fill the engine with oil. The cam can not rust if it's submerged in oil. If you don't remove the push rods, oil will leak out of the open valves.

Charlie


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