General Questions - Oil Accumulators

[ForgedCrank]

I know this is an oddball topic but was hoping someone might have experience in this arena. Hope this is the right sub since it's engine related, just not specific to an engine.
Anyway, due to the number of vehicles I have, most of them sit for long periods of time. When I do go to start one of them up, I spend a ridiculous amount of time having to prep by finding the right fuse, disabling the fuel and cranking the thing for oil pressure... putting way too much load on the starter, etc. all in an effort to pre-oil the mains and cam etc. before startup.
So anyway, my idea was to investigate using an oil accumulator, but just for startup. I figured if I could set one up with a low pre-charge pressure that is well below operating oil pressure, that would do a nice pre-oil of the engine oiling system before startup. But, the ones I am looking at are completely mechanical in nature, meaning that when the engine operating oil pressure drops below your pre-charge PSI, oil will be forced out of the accumulator into the engine oiling system. Then, when oil pressure goes higher than the pre-charge pressure, oil will pump back into the reservoir until full... and the cycle continually loops. One thing I don't understand is how this system can be used to HOLD a full reservoir of oil when the engine is shut off (saving for the next startup), and then how to release that oil to pre-charge the oiling system prior to crank.
There is a piece in this I am missing somewhere, or I'm just trying to use this for an application for which is is not intended, I'm not entirely sure.
These appear to be generally used for racing and off road applications for when the sump might end up dry momentarily during operation. This obviously isn't my main goal, mine is just for startup oiling. Something with a 12v pump would probably be more appropriate for my application here, but I can't find anything like that.
Do any of you have any experience with these things, or experience in doing what I'm attempting here? Any advice?

 

[sgtsandman]

While I appreciate the concept, I'm not sure how much benefit it would provide since, generally speaking, the only time I can think of oil starvation being a thing for the average engine, is if it has been sitting for a very long period of time, it is really cold and the oil is really thick, or when the engine is first built/rebuilt. Though, assembly oil is usually used in those processes.

As long as the oil pump has maintained it's prime, the circulation of the oil happens pretty quickly and the residual film left when the engine was last run is usually enough to protect the metal.

There is a proceedure you can use in most vehicles where you press the pedal all the way to the floor and hold it while cranking the engine. It is meant mainly to clear a flooded engine but has the side effect of charging the oil system. I and others have used this for charging the timing chain tensioners on the 4.0 SOHC engine after they have been replaced with new ones.

If oil circulation during really cold weather is a concern, you can either go with a thinner oil during those months or install a block heater. The block heater has the benefit of indirectly warming the oil as well as the coolant in the engine, preventing the coolant from freezing and cracking the block.

If there is another concern that you have that I'm missing. Let me know.

As of right now, the idea isn't a horrible one, it's just normally not necessary.

 

[ForgedCrank]

While I appreciate the concept, I'm not sure how much benefit it would provide since, generally speaking, the only time I can think of oil starvation being a thing for the average engine, is if it has been sitting for a very long period of time, it is really cold and the oil is really thick, or when the engine is first built/rebuilt. Though, assembly oil is usually used in those processes.

As long as the oil pump has maintained it's prime, the circulation of the oil happens pretty quickly and the residual film left when the engine was last run is usually enough to protect the metal.

There is a proceedure you can use in most vehicles where you press the pedal all the way to the floor and hold it while cranking the engine. It is meant mainly to clear a flooded engine but has the side effect of charging the oil system. I and others have used this for charging the timing chain tensioners on the 4.0 SOHC engine after they have been replaced with new ones.

If oil circulation during really cold weather is a concern, you can either go with a thinner oil during those months or install a block heater. The block heater has the benefit of indirectly warming the oil as well as the coolant in the engine, preventing the coolant from freezing and cracking the block.

If there is another concern that you have that I'm missing. Let me know.

As of right now, the idea isn't a horrible one, it's just normally not necessary.

appreciate the input.
You are correct, this isn't something that is a necessity, it's in the IWANT category. I'm always looking for something stupid to experiment with, and this would serve a useful purpose. I could maybe even get together a parts and build sheet so others could make their own after I figure it out and stop paying Moroso 350 bucks for the the canister alone.
I have a lot of vehicles that sit for 6+ months, and the mains and cams are dry by that time, minus maybe a very small residual amount, but the passages and everything slowly empty out from sitting for so long. I can tell by the rattling when they start up if I don't do a cold crank first to build some pressure. the Dodge's seem to be the worst for this, when dry they sound like a bucket of marbles for about 1-2 seconds when the fire up. It makes my teeth itch and my eye starts twitching.
I do use the "flood clear" mode on a couple of vehicles that have that available (both Fords), but it's still one of those things that bugs me, all that extra cranking on the starter, not to mention after sitting so much, many times the battery is already a bit low as well. I keep battery tenders on some of them, just not all.
In the end, I see this as turning into a DYI thing. I've been searching and reading tonight some more and I now see that there are kits available to automate this. Most guys who use this have them for starvation compensation in race applications, so they just use a manual ball valve to trap the last oil and pressure before they shut off the engine so it can be used at next startup. But there are also solenoid operated kits that are rather pricey that do it automatically. I'm interested in the solenoid setup mainly because I don't want to get under the hood every dang time, and I most certainly don't want a blazing hot oil line piped to the inside of the car for a manual valve.
The high dollar ones like Moroso use a cylinder with a piston to separate the pressure chamber and the oil. This is apparently method used in an attempt to eliminate frothing etc. But I don't care about that as it wont be an issue for my application. I'm thinking about building it myself with a simple pressure chamber (no piston), and using gravity+the shutoff oil pressure of the engine for the next startup cycle. I think I can get probably 30PSI of pressure in the chamber and have the engine system fill it before shut down, use a solenoid operated valve to close it off, then shut down the engine. Then i'll have that oil + ~30PSI to release next time right before startup. The one thing that has be second-guessing that is I may be misinterpreting the behavior. with 30PSI of pressure, all oil, there will be no air pressure volume behind it (or very little) and I think that as SOON as I released it, the pressure would hit zero, with no buffer to push out the majority of the oil, leaving it as useless. the piston+air pressure almost seems like it's going to be required in order to push all of the oil out and up into the engine oiling system. This may end up also needing a cheesey onboard air compressor to make it work. I'm just going to have to experiment with it. I don't really need to have oil PRESSURE prior to startup, I just need everything to have a film, and for the passages to all be already mostly full of oil so there is no delay in building operating pressure.
I think it would be relatively easy and inexpensive to DIY one using a filter sandwich plate for the connection. I'm chewing on the oil line part right now. this is a critical failure point, so I can't have sketchy lines going from the sandwich plate to the accumulator, that could end badly one day.
I know this is long, but I'm mostly just thinking out loud... just wait til I start sipping on the home-made blackberry brandy!

 

[Bill]

If you tear down an engine that has been sitting for years you will find a film of oil on the bearings. They don't dry out. Any engine I've changed the oil and filter in has took about two seconds to gain pressure. If the oil filter has an anti-drainback valve there is still oil in the gallerys. I don't think you have anything to worry about if you just start up the engine. In some parts of the country I would be more concerned with water in the oil from condensation.

 

[ForgedCrank]

This is more like what I was thinking earlier and will probably be the route I go.
This guys setup is a bit sketchy though, i wouldn't trust it with the lines he used. I'm not a fan of using the oil drain plug either, but I don't see any other way without dropping the pan and doing some welding, something I am far too lazy to do.
I think this concept is solid with a few changes like locating the check valve at the pan and using hard lines with flare fittings.

 

[scotts90ranger]

Although I get it I'm not sure it would help much... being me pretty much everything I have is old and used, I don't own anything with less than 200k on it... my '00 Explorer was ridden hard and put away wet well before I got it at 206k, pretty sure I took care of it better than it had before. I took that engine apart at 255. mainly because it needed to come out to fix the motor mount so I freshened it up. At that point the cylinder walls were still straight with cross hatching still and the bearings were just starting to show color, gave it a hone and new bearings and rings and put it back together... I've been into turbo 2.3's too with similar but they usually have cylinder wall wear (but I just honed those too and put them back together, didn't have a better block at the time).

The dumber way to prime the system is the "clear flood" mode where you go to WOT and crank, it's supposed to turn off the injectors so the engine won't start which would let you prime the oil system. That doesn't work on my '97 Ranger and haven't tried on the rest of the fleet...