Oil system: pre oiler, accumulator, etc.

[Will L.]

I am planning a pre oiler to eliminate no oil pressure start up. It is long reported this is when most engine bearing wear occurs.

Please post any knowledge, theories, concearns, etc.

I have worked on rigs with them, have friends that have them, installed a few on fleet trucks, but I never bought/ made one myself.

What is it?
Basically a tank that holds “X” amount of oil in it, has a charge of pressurized air in it. Then an electric solenoid that you wire to a switch you turn on before starting. Hit the switch, solenoid opens allowing the pressurized air to push oil into the jotnals and giving you oil pressure befpre cranking the engine to start.

When you start the engine, the normal oil pump builds pressure and pushes “X” amount of oil back into the canister at that same pressure. Now you turn off the solenoid, your engine is at it’s notmal oil
Level and drive normally.

Because the oil pump has refilled and recharged the canister with oil at pressure, it is ready to go the next time.

The electric solenoid gets option replaced with a simple ball valve but you have to open hood every start up, or rig up a choke cable to operate the ball valve every start up.

 

[ak diesel driver]

I have a preluber on my 428cj. Different set up than yours. It's just an electric pump that pumps oil from the crankcase. Not sure if it's even made anymore.

 

[JayTheCPA]

Have seen notations of benefits from these systems for years as well.

Agree that the theory of it should work to a degree.

While the pre-oiler system will push oil to the top-end, one limitation I see is that it does not do anything for the cylinder skirts. Although, perhaps this is outside the scope of the original question . . .

Anther limitation is the oil's viscosity when the pre-pump discharges. In the Winter, it is tough for a bean-counter like me to see how thick oil is going flow very far before the starter engages. Sure, that volume will spread ahead of the oil pump's volume, but just how much and how far is the question. Same holds true for cold-starts during the Summer but to a lesser degree.

If I did do a pre-pump system, it would need a way for me to easily dump its contents during an oil change. Having an oil cooler retain its volume is bad enough.


Overall I put the pre-pump in the same arena as nitrogen in the tires. Sure, there is benefit. But if it is such a great thing, why does it not have wide adoption and fan-fare like a bigger diesel exhaust?

 

[Will L.]

OK, I'm looking into an accumulator for my Cummins and see different thoughts as 'to add oil or not add oil' to the crankcase with the install of one.....a 3 quart accumulator will never see three quarts maybe 1.5 to 2 quarts at best depending on pre-charge pressure.

My concern is excessive crankcase pressure causing leakage at the crank seals and oil blocking the turbocharger oil return causing leakage past the turbo bearing housing seals with any extra oil.

Your thoughts?

I have messed with only 3 of these units that were air charged for first use only, then use the factory oil pump to refill with oil and recharge with pressure for all re-use until the oil change is performed, when you drain it all and chave to charge with air at that time.

My understanding is there isnt any excessive crank case pressure from these systems, because if your normal oil pump gets to say 80 psi, that is how high you charge the canister.

It could over flood the oil volume in the engine, but if you “tune” it to the right amount of pressure: match your charge air exactly to your peak oil pressure, the excess oil would only be in the engine for a couple minutes at most.

While having too much oil in the pan is not good for windage issue and the crankshaft being in a bath of oil- that is only a problem at high rpm, and robs power. The couple of seconds you may be accelerating hard right after start up, the oil pressure will build quickly and recharge the canister that much quicker.

How much oil the canister holds- need research by different manufacturers probably.

But in an air/factory pump charge system- just tapping the oil pressure gauge at the end of the circuit means you could fill canister with say 2 quarts, pressurize can, and open valve. Once peak oil pressure is obtained at the end of the circuit, close valve. Drain and measuring canister content. For example say you are left with 1.1 quarts. You now know it takes 0.9 quarts to charge the engine. So maybe use 1 quart in the canister and then worse case scenario, the most you could flood the system with is 0.1 quart.

 

[Will L.]

I have a preluber on my 428cj. Different set up than yours. It's just an electric pump that pumps oil from the crankcase. Not sure if it's even made anymore.

I have seen these in use on old semi trucks and 1 plant engine. They used an electric pump to draw oil from the pan with a “T” at the drain plug. 1 had a fitting in the side of the oil pan close to the bottom. They had a seperate oil pressure gauge. Then when turned on run until it maxes pressure, start engine. Once the normal oil pressure gauge was at normal level, turn off the prelube pump. Just a normal oil scavenger pump is all they looked like.

My understanding of these is, if operator forgets to turn it off, you could experience an issue as the electric pump and factory oil pump fight each other at high rpm.

The advantage of the air charge pump is if the valve fails open, it cannot affect factory pump during operation.

The advantage of the electric pump system is if the canister style valve fails open: when you shut off the engine, all the oil will drain out of canister, causing an over fill in the pan if you did not “tune” it to the proper amount of oil required. That could lead to crankcase over pressurized situation.

If you get the chance to post any pics, that would be nice to see.

 

[ak diesel driver]

IIRC it has a control box on it and shuts it down automatically.

 

[ak diesel driver]

I believe this is the one I have. Company appears to have switched to the accumulator style.

 

[ak diesel driver]

A guy could make it dirt simple by just using a momentary switch

 

[Will L.]

Have seen notations of benefits from these systems for years as well.

Agree that the theory of it should work to a degree.

While the pre-oiler system will push oil to the top-end, one limitation I see is that it does not do anything for the cylinder skirts. Although, perhaps this is outside the scope of the original question . . .

Anther limitation is the oil's viscosity when the pre-pump discharges. In the Winter, it is tough for a bean-counter like me to see how thick oil is going flow very far before the starter engages. Sure, that volume will spread ahead of the oil pump's volume, but just how much and how far is the question. Same holds true for cold-starts during the Summer but to a lesser degree.

If I did do a pre-pump system, it would need a way for me to easily dump its contents during an oil change. Having an oil cooler retain its volume is bad enough.


Overall I put the pre-pump in the same arena as nitrogen in the tires. Sure, there is benefit. But if it is such a great thing, why does it not have wide adoption and fan-fare like a bigger diesel exhaust?

The piston skirts- if you have oil squirters that are a constant feed style, maybe some gets on there. But piston skirts shouldn’t be hitting on start up. If they do, you have big issues. Bearing wear is the main target.

As to cold oil- wether the electric oil pump or the charge canister type- it gets same results as the factory oil
Pump. Push oil through journals until a gauge says at pressure desired. Then start engine. How you do it now is start engine with bearings dry, then factory oil pump starts pushing oil through until it gets to the end of circuit and starts to build pressure.

No, it won’t move as much oil as fast as factory oil pump, but maximum volume/pressure isn’t required to fill system with enough oil to be good.

The factory oil pump for squirter blocks is a
Melling M255-294s. Specs from Melling:
@800 rpm is 25psi.
@2000 rpm bypass is @90psi (max spec is 94psi) & 3.76 gpm

GM says 8psi at idle is bottom spec.

We dont have to hit high amounts of pressure. If you read it at the front right port of anything above 8psi, you are good.

I don’t know why it isn’t spoken alot about except that so many people have no desire to keep their rigs for 200,000 miles. I have friends that replace vehicles every 5 years no matter what. New toys are fun? Things like exhaust or other engine upgrades are something you install Monday and Tuesday get the rewards. This is investment now and you never notice the reward, until the others people engines of same age are failing, while you keep on going. Just like a high quality oil vs junk.

Also depends on the engine and it’s use. The ls 6.0 in my suburban- oil changes with average dino oil went 30,000 miles. Yes it was sludging the engine. Probably bypassed filter on cold starts in winter. But I know that engine can handle it up to 250,000 miles doing it. The truck was sold at just over 200,000 and I explained to the buyer what I did, and that if he plans on getting it much over 300,000 miles, he will need to tear down completely, new bearings, oil pump, and a serious hot tanking.

But a 6.5 diesel- NO! FRIGIN! WAY! Also I plan on a zillion miles, So I am investing for the long haul.

Oh yeah- oil change drain. Just hit the switch and let it all drain into pan when you first start. The system will be empty. After a few minutes you turn off switch. If it is a bladder tank, then you never have to recharge with air. If it is simple tank, then you fill the tank with predetermined amount of oil needed and close valve. Then charge with air like filling a tire to the predetermined pressure. My buddy with one like this on his Toyota - it adds about 5 minutes. But you know how long after oil change it runs dry? Never on his...

 

[ak diesel driver]

I agree with Jay on one of the cons of the accumulator system. How do you get all that oil out when you change the oil? I guess you could trigger it to pump all the oil out then change it but then you'd have a dry start

 

[Will L.]

I edited my last post- read last paragraph.

Here is a couple YouTube vids of the style with a canister and no bladder. Not great videos, but you get idea easy enough i think.

One has timer so no switches. Another has simple switch.

 

[Will L.]

Here is one company selling a kit.

EnginePreLube.com is for sale | HugeDomains

Get set up with a new domain name right away. Affordable payment plans to fit any budget. Friendly customer support.

www.engineprelube.com

And their description much better than mine obviously:

http://www.engineprelube.com/images/Insta-Lube-installation_picture-roll.pdf

 

[JayTheCPA]

One other question I have is benefit of a pre-lube system when synthetic oil is available. While the layer of oil at start-up is thin, synthetic has notation for good lubrication even in thin layers. The pre-lube systems came out when synthetic was a novelty item and made more sense with dino oil.

As always, I only know what I read and look forward to inputs from better experts . . .

 

[THEFERMANATOR]

All you really need is something that can purge the air from the oiling system. 8f you purge the air and hold some pressure in the oiling system before cranking, then the engines oil pump will push the actual oil to everything. The acvumulator is there just to stop that period of time it takes for the engines oil pump to purge the air out of the oiling system.

 

[Will L.]

The synthetic oil helps, and higher quality synthetics tend to “stick” in place after shut down. And being a thinner oil allowed because synthetic oil gets through the system slightly faster, you can coat things slightly quicker.
But teating from the oil company I worked at, still showed the wear occurs.

The oil bleeds out of the bearings, runs off the top surfaces of jounrals, etc the longer it sits.
Air trapped in any jornal yes would create a void, but it isn’t like air is leaking in somehow and could be vacuumed out. As the oil seeps out it leaves the void. Measured volume of oil should be minimal but exists because everytime you start it takes a little time to build pressure which is the absence of a void. Pumping in the needed oil is the easiest method of filling thr void which the air then occupies.

 

[Will L.]

I will be using the 3qt, precharge is only 7lbs i think so it would hold right at 3qt. The directions say to let run then shut off where the valve closes then check oil level.

I stole this quote from the other thread.

Both you and fellow traveler mention the 3 quart unit.
Something I dont get yet is how to determine what size tank would be required.
If using the post shut off turbo bearing/ seal cooling flow, ok. Also if trying to use as an emergency time extension like if you get an oil leak, it buys more time to shut off engine before damage occurs. So for those functions I get why a 3 quart.

But if just start up- why not one half size?

 

[Twisted Steel Performance]

Why not, more oil in the system is a good thing, and with a 8-10sec glow time how much oil would be pushed through the system under 60+ lbs of pressure? I don't know myself...

For me I have plenty of room and the tank isn't big at all...

 

[Twisted Steel Performance]

I will use this one and some of their accessories, valve, mount, check valve, etc...

https://www.cantonracingproducts.com/canton-24-006-accusump-3-qt-no-valve/

24-270X Accusump Pro Electric Valve Kit

The Electric Accusump Valve kit provides a convenient way of operating the Accusump. They are useful when the accumulator is mounted in a hard to access location. When wired directly into the ignition switch the Accusump can be operated automatically to provide pre-oiling. The kit comes with...

www.cantonracingproducts.com

24-200 Mounting Clamps Steel For 2/3 Qt Accusump Oil Accumulator

Steel band mounting brackets for our 4-1/4" Dia. Accusumps. Mounting clamps are required for all Accusumps. When used on each end of an Accusump they provide the proper support at the end caps to ensure the tube does not become distorted. These are sold as a set of two stainless steel T-clamps.

www.cantonracingproducts.com

24-280 Accusump Check Valve 1/2" NPT

Check Valve ensures all the oil being discharged out of an Accusump goes to lubricate the engine bearings and is not fed back toward the pump. For use in systems where a remote oil filter or a cooler is used. Uses 1/2" N.P.T. female threads.

www.cantonracingproducts.com

 

[Will L.]

Yeah, wondering how much oil required. I dont have much extra room.

Also having the desire to do as much as possible with little cash to get there, was thinking of trying so source parts cheaper. A metal cylinder to withstand 100 psi should be easy. I was thinking of cleaning out fire extinguisher and going from there.

It’s not hard to get $500 invested, but I can’t help but think I should be able to do it all for under $150.
I think the cost of the kits is a big reason more people dont do it. That’s why I never have yet.

 

[WarWagon]

The volume of oil can be guessed by oil pump GPM and time. The cold oil testing from the military posted here give you time vs. temp with an X factor of how used the oil is.

@Will L. When you are knocking down walls during Urban Assault or extreme off road will you ever uncover the oil pump pickup screen? LS2 powered Trailblazer SS engines had the oil pick up in the front. Perfect way to spin rod bearings with a good launch on track day! An accumulator open 100% of the time would help. A better oil pan and pickup assy in the rear, duh, was/is available from the aftermarket.