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An easy oil circulator for stored engines. Engine pickling

Hartstoc

Well Known Member

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:


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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
 
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
 
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
 
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.
 
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.
 
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
 
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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.
 
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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
 
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.


No. Just no.
 
What Charlie said^^^.

The cup on the lifter body is what moves and takes up the lash gap when the lifter is pumped up with oil pressure (usually needs some 25 or more psi to come up) - and there by pushes the lifter down (Newtons 3rd) to hold it against the cam lobe. Once you remove the pushrod, theres too much of a gap for the lifter to put any pressure on the cam lobe. Obviously, it would then fall out of its bore, 'cept for the circlip at the top of the bore as you mentioned.

If you get a chance some time, take a hydraulic lifter apart. Quite an ingenious but simple device (hint: dont use a magnet to get it apart - that'll magnetize the individual parts and it wont pump up properly anymore)
 
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.

Does it really do that? Or is the oil sump bolted under the crankcase and mostly separated by casting.
 
Does it really do that? Or is the oil sump bolted under the crankcase and mostly separated by casting.

Ah yup, youre right. Theyre separated - I was thinking of a transmission I'm working on and flipped my thought gears. My bad.
 
What Charlie said^^^.

The cup on the lifter body is what moves and takes up the lash gap when the lifter is pumped up with oil pressure (usually needs some 25 or more psi to come up) - and there by pushes the lifter down (Newtons 3rd) to hold it against the cam lobe. Once you remove the pushrod, theres too much of a gap for the lifter to put any pressure on the cam lobe. Obviously, it would then fall out of its bore, 'cept for the circlip at the top of the bore as you mentioned.

If you get a chance some time, take a hydraulic lifter apart. Quite an ingenious but simple device (hint: dont use a magnet to get it apart - that'll magnetize the individual parts and it wont pump up properly anymore)
9
My external oil pump by itself maintains 40psi at the port where oil pressure is normally measured in the lower left side of the crankcase, so at least 1.5 gpm is circulating through all of the oil galleys, bearings, and pressurizing the lifters. I?ve worked on automotive hydraulic lifters that have retainers that prevent them from pushing apart beyond a maximum length(in fact there is a spring inside that has to be compressed to install the clip). This may be true for Lycomings as well, but there is also a plunger that acts upon the push rod that can be removed when the cylinders are backed out enough to remove the pushrod tubes, see:

https://youtu.be/sRtKiV6QYaE

My concern is that if I remove the push rods and operate my external pump, this plunger will be forced out into the empty tube, and I?m not sure it would be easy to reinstall them with the tubes in place. If I could be confident that this would not be a problem, I would remove the pushrods, bring the system up to pressure with the external pump, crank the engine vigorously with the spark plugs removed, bringing system pressure up near 50 PSI, and afterward remove the #2 jug to allow me to verify or refute that this procedure has indeed splashed oil on the cam lobes.

This would be valuable information to post on VAF one way or the other, and would validate the use of an external pump in this manner if the cam did get oiled. I?d be willing to go to the trouble if I could be convinced that pressurizing the system and spinning up the starter with the pushrods removed would not lead to some such problem. I did spin the engine for about 20 seconds this way with the pump operating but fully assembled except spark plugs, and I guess I could just repeat that and pull a jug, but some posts here have me worried that I may be spinning a bone-dry cam against the lifters.- Otis
 
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.

The engine oil pump prevents any significant reverse flow when my external pump is operating. If you look at flow diagrams of the vernatherm circuit, you can see that injecting oil anywhere in the cooler loop will pressurize the entire system in the same manner as does the engine driven pump regardless of the state of the vernatherm valve(i.e. the oil cooler loop remains fully pressurized regardless of valve position- the other end of the loop is always open)- Otis
 
Obviously, it would then fall out of its bore, 'cept for the circlip at the top of the bore as you mentioned.
You just keep giving erroneous data on this thread. There is no circlip in the lifter body and the oil pressure will blow the plunger assembly and cup out of the pushrod tube. without a pushrod installed.

Larry
 
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Does it really do that? Or is the oil sump bolted under the crankcase and mostly separated by casting.

No, it doesn't. That is a major design no no. That would cause extreme cavitation and the oil would become entrained with air bubbles, reducing the effectiveness of the oil system across the board.

Larry
 
You just keep giving erroneous data on this thread. There is no circlip in the lifter body and the oil pressure will blow the plunger assembly and cup out of the pushrod tube. without a pushrod installed.

Larry

Ok fair enough. I'll step back from the conversation and listen while you guys help the OP out with detailed explanations so we all can learn instead of just throwing stones at me for trying.
 
No, it doesn't. That is a major design no no. That would cause extreme cavitation and the oil would become entrained with air bubbles, reducing the effectiveness of the oil system across the board.
Larry

THIS...is why it is very important to not overfill an auto engine with oil since in auto engines the oil sump is open to the lower end of the crankcase.
 
I'm still trying to understand how an external pump is a benefit, when the storage lubrication scheme still depends on spinning the engine with the starter, which brings the internal pump into play. I suppose the additional pressure would increase leakage volumes from the bearings, thus maybe throw a little more oil on the cam.

Personally, I'd seal it and fill it with a preservative oil or oil with additive. Done, every surface protected, zero wear.
 
I'm still trying to understand how an external pump is a benefit, when the storage lubrication scheme still depends on spinning the engine with the starter, which brings the internal pump into play. I suppose the additional pressure would increase leakage volumes from the bearings, thus maybe throw a little more oil on the cam.
Personally, I'd seal it and fill it with a preservative oil or oil with additive. Done, every surface protected, zero wear.

I agree!!!
 
I'm still trying to understand how an external pump is a benefit, when the storage lubrication scheme still depends on spinning the engine with the starter, which brings the internal pump into play. I suppose the additional pressure would increase leakage volumes from the bearings, thus maybe throw a little more oil on the cam.

Personally, I'd seal it and fill it with a preservative oil or oil with additive. Done, every surface protected, zero wear.

Dan- You may well be right, But I wonder if you really can completely fill a mounted engine all the way up to the cam, or if entrapped air would prevent it. You would also have to put up with a lot of oozing past imperfect seals around valve stems, etc. Then you would also have a lot of oil in cylinders and induction and exhaust system to burn off when first running the engine.

My hope was that artificial circulation of a large volume of oil concluding with a good spin of the starter would coat all surfaces thoroughly , including the cam, but removal of at least one jug would be required to verify that. Conventional wisdom assumes that the meager output of the engine pump is all you have going for you when just cranking the engine. I was able to see that the cylinder walls were fully coated with fresh oil using a mini camera. I did at least get a good feeling from purging air from a new filter and circulating fresh clean oil through all of the oil galleys and bearings and lubricating the rings. I have other fluid transfer needs that justified the cost of the pump.

I’m really just trying to explore and learn more about this topic. I didn’t anticipate that my engine would be down for so long a time when I took it out of service, or I’d have done more in the way of running preservative oil, etc, so I’m looking for ways to protect an engine that has already been sitting quite a while. I guess I’ll have to pull a jug if I want to bring this to a full conclusion.- Otis
 
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Dan- You may well be right, But I wonder if you really can completely fill a mounted engine all the way up to the cam, or if entrapped air would prevent it. You would also have to put up with a lot of oozing past imperfect seals around valve stems, etc. Then you would also have a lot of oil in cylinders and induction and exhaust system to burn off when first running the engine.

My hope was that artificial circulation of a large volume of oil concluding with a good spin of the starter would coat all surfaces thoroughly , including the cam, but removal of at least one jug would be required to verify that. Conventional wisdom assumes that the meager output of the engine pump is all you have going for you when just cranking the engine. I was able to see that the cylinder walls were fully coated with fresh oil using a mini camera. I did at least get a good feeling from circulating fresh clean oil through all of the oil galleys and bearings and lubricating the rings. I have other fluid transfer needs that justified the cost of the pump.

I’m really just trying to explore and learn more about this topic. I didn’t anticipate that my engine would be down for so long a time when I took it out of service, or I’d have done more in the way of running preservative oil, etc, so I’m looking for ways to protect an engine that has already been sitting quite a while. I guess I’ll have to pull a jug if I want to bring this to a full conclusion.- Otis

Many engine experts indicate that a good portion of "normal" metal to metal wear over the life of an engine (excluding break in wear, of course) comes from the starting phase of running, when gravity has removed a good portion of oil film that can't be replaced until high Idle rpm is reached and enough time elapses for splash lubrication to replace it. This would support the general consensus here that your not likely to see much help from splash lubrication at starting RPMs.

I am with Dan here. A lot of effort for an unlikely benefit. We see most corrossion in the barrels and cam/lifter interface. These are the two areas that are quite unlikely to see oil from your proposed method. Bill's approach is pretty simple to deploy and virtually fool proof. You can't have corrossion without moisture.

Don't forget that the sytech starter has a VERY small duty cycle. Less than 5 or 10%, if I remember correctly.

Larry
 
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Many engine experts indicate that a good portion of "normal" metal to metal wear over the life of an engine (excluding break in wear, of course) comes from the starting phase of running, when gravity has removed a good portion of oil film that can't be replaced until high Idle rpm is reached and enough time elapses for splash lubrication to replace it. This would support the general consensus here that your not likely to see much help from splash lubrication at starting RPMs.

I am with Dan here. A lot of effort for an unlikely benefit. We see most corrossion in the barrels and cam/lifter interface. These are the two areas that are quite unlikely to see oil from your proposed method. Bill's approach is pretty simple to deploy and virtually fool proof. You can't have corrossion without moisture.

Don't forget that the sytech starter has a VERY small duty cycle. Less than 5 or 10%, if I remember correctly.

Larry

More good points , Larry, but note that I’m flowing a LOT more oil than can be achieved with the starter, and that with plugs removed and a very powerful battery, my B&C starter was cranking pretty close to unloaded RPMs, so I think I'm creating a new condition worth exploring here. The starter barely got warm during several 15 second cranking cycles. I did see a fresh oil film on the entire cylinder walls after the spin, so if oil is getting splashed there it may be getting splashed on the cam as well. There are no “return lines” in the oil system, controlled leakage around bearings is how oil gets back into the sump. The rod big-ends pass very near the cam with each revolution, and oil is being forced out around the big end bearings continuously. I still think this is a question worth asking, but have to admit to an abundance of ignorance about what is really going on in there!- Otis
 
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