Yanmar - How long should it take for oil pressure to come up from a cold start?

Thank you Bigfoot some people know,-- some just demand that they know.


Like I said take the harmonic balancer of an ole Jag and it would break the crank.

Reversion was something I brought up referring to the breathing characteristic of the 5 cylinder.

Some V 6 engines had dummy cranks to balance the motors spinning within the crank case, However tortional vibrations is my prob not balance.

 

I think it was Fred who mentioned pre lubers. I have had a look at this and yes it does appear to be the way to cure the prob without too much fuss.

A yanmar expert has finally told me that the rattle is normal as is the oil filters draining on the 6LP. Taking 6 seconds to prime is'nt a problem due to the tight clearances on the 6LP. Mine take more than that.

Ok pre lube is a tank that looks like a divers tank upside down with a electric valve, it simply connects to the oil gallery via a 3/8 T fitting on the sender unit. Oil pressure forces oil onto the tank which then you turn off when max oil pressure is reached. This pressure is released when next cold start is required.

Great send me 2 , usps 59dollar, ups227 dollar,--fed ex 330 dollar.

The box is 6x14x14 16lbs. I could get a one way economy seat for 330 dollars!! nearly. I cant use UPS it is not trackable and it wont arrive.

So plan B 2 old fire extinguisher bottles that look amazingly like the original equipment!!!, 2 valves that I can get for 50 dollars each again look like original, some 3/8 fittings and some hydraulic pipe that I could improve on and use swaged fittings.

Its such a lovely simple system. Switch on pre lube, oil alarms should stop, guage starts to read, start engine. Providing I fit a large enough system to pressurize and fil the empty oil filter.

A pump can be used but you need an oil supply, not easy, you need another filter so you are not pushing unfiltered oil in the galleries. Bigger wiring, more maintenance etc etc.

 

seems to me the tank system is a one shot deal, where as an electric pump will run as long as you have current of course the inlet to the pump would be a little more difficult to rig up and a check valve on the outlet side and your in business and it could serve as an emergency pump, just in case both pumps failed on both engines, well it could happen

http://www.pre-luber.com/index.htm

is one i found

 

Using a simple bottle isn't as good as an Accusump, and here's why.

With an Accusump the accumulator does not start filling until a specific starting pressure is reached, and the Accusump drains essentially all of its oil into the gallery when it is opened.

A simple bottle that is pressurized by the oil, with an air trap above it, has essentially little or no oil pressure in it as the amount of oil in the bottle gets low. Near the end the bottle is just dribbling oil out and the accusump is pushing its oil out into the gallery. With a simple bottle system the system drains oil from the engine into the bottle as the oil presure is increasing, just when the engine needs oil. Or if you shut the valve off, it drains oil from the engine when the engine is running, so in that case you need an orifice to control flow into the bottle.

In short, the Accusump gets more oil at pressure out into the engine than a bottle of similar size. It has orifices that are based on the accumluator size to provide oil to the accumulator at a proper rate so that the engine doesn't lose oil flow when it actually needs it.

The accumulator systems will do what Frosty wants to do, and it appears that the pump systems have a lot more that can go wrong with them. An Accusump system is about $100 less expensive than the electric pre-lube system noted above. Either one will do the job. Just spend a few bucks and do it right. If you try to cheap it out, and do a home made system it may work just fine, but it might not and if it doesn't it isn't worth the risk to your engines. I am thinking specifically about orifice sizes and filling of the bottles here, how to open the valves ect...

 

Its such a simple devise its like saying a bucket wont work. Funny we had this same conversation over a beer last night , one guy was unable to grasp the idea and said the same thing.

On initial start up the engine pumps oil into the tank accumulator, nothing will stop that, then the 12 solenoid valve is manually shut when the oil pressure is at its highest. There it sits till the next start where the oil is released not drained into the engine. Your very own suggestion of accusumps web site adequately explains the simple theory.

http://www.accusump.com/accusump_tech.html

http://www.autoenginelube.com/

Damage to my engines?

Providing all fittings and tanks are clean I don't see what you mean. A discharge of any oil at all into my empty filters is a million miles in front of what I have now.

3/8 fittings is hardly considered high flow and a 3/8 rubber hose to a valve would already be a resistance over the 1/2 inch galleries in the engine.

 

engine configuration balancing

That is true, the V6 is much trickier to balance. The straight six is balanced by his nature, he is the smoothest engine possible (4 stroke).


Have never heard about reversion forces either, but free forces of the first, second and third order are what you have to fight, when you try to balance a IC engine (except 4 cyl. Boxer and straight six).

If you have´nt heard about these forces, or terms, then IC engines was not what you have studied.


Studied, ran lab tests on ic engines, perhaps the terminology is different in Europe than here re forces of the second order etc But upon reading your post and others, perhaps, I did not explain balancing.
Most mechanically connected people know about the term "to balance an engine" as being balancing the crank by spinning and weighting or drilling and measuring the weight of components such as con rods, pistons etc and matching them by weight. This is not what I am talking about.
It is dynamic balancing of all of the reciprocating components AND more importantly the effect that uneven loading of the crankshaft due to the forces that are imposed upon the crankshaft due to compression of the mixture which loads the crank, the forces from the power stroke upon ignition, and more importantly the forces on the crank due to accelerating the piston, con rod mass up and down the cylinder bore. And of course these happen at different angular positions of the crank.

So if you do the calculations and imprint them on the balance graph, you will see that even if all of the similar components are balanced by weight, that when you run the engine for a given rpm, that the whole system is not in balance. Plus and this is important, the load that the crank is putting out the shaft factors in.
So it is dynamic balancing that I am speaking here. A V6 cannot be balanced perfectly even with the offset big end bearing journals, dynamically.

hope this clears things up some of the confusion

 

Frosty,

Think about it for a minute. Your "bucket" is open to the pressure side of your oil pump with essentially no pressure in it when you go to start your engine, then before you can put any pressure to the bearings you have to put oil into the bucket. That is, your accumulator has the same pressure in it as does your oil gallery. What happens is that you are going to see a big lag in pressure rise during startup. Oil will flow to both the bearings, and to the pressure bottle, but the pressure in both is the same, so, depending on the size of your bottle and how fast it gets pressurized, you are going to have oil that should be going to your brearings, going into the accumulator. While your homemade accumulator is filling, just after startup, your engine isn't getting the oil it is supposed to get. The Accusump has a pressurized piston arangement that prevents oil from flowing into the Accusump until you get pressure to the bearings. Above that minimum pressure, then oil flows into the Accusump, but at that point the system has plenty of oil and the pressure at the bearings is never lower than the minimum. A homemade upside down fire bottle won't do that.

While your galleries are half inch, the restriction in the system is the bearing clearances, and those are in the thousandths of an inch. Opening a 3/8's line would be like a dump compared to the bearing clearances. If you put a gage on your bottle and compared it to your oil pressure gage on the engine, there isn't going to be any difference. If you want it to work at all you need a small restrictor so that you get pressure to the bearings first and then your bottle fills slowly. Unfortunately, you want the output dump to be large so that the pre-oiling gets done quickly. Maybe a one way valve with a small restrction orifice in it on the inlet side and a dump valve on the outlet would work. But I think that the Accusump system is a better idea.

Unless you know how much oil your pump can put out, and what minimum pressure you need versus engine speed, you are asking for trouble. You might get lucky and it might work, but it also might spin the bearings and ruin an engine. To my mind, to save a few dollars, and not buy something that you know will work is not a wise decision.

 

You are trying to educate the uneducable. Frosty now knows everything about the subject.

 

Yea, we have a situation where somebody is bull-headed, cheap and lives in frickin BFE so even if he figures out what he wants to do, he can't even get on line and buy what he needs to do the job right, but then he bellyaches about his problems....

Maybe he ought to start it up and let it rattle one more time and drive it to someplace where he can buy what he needs to do it right. Australia is close enough... Frosty, head south...

 

Why do you think oil will rush into the tank first? Its the tank that has just primed the engine. The tank wether it has a piston with a spring or just air will work the same way.

The accumulator is not on the side of the oil pump, the accumulator is after the oil pressure relief valve, the oil filter and 3.8 fittings and pipe. The oil will flow towards bearings at an equal rate.

It would appear that you are understanding the idea but feel that oil will for some reason flow into a closed tank??? try blowing into it and see how much air you can get in.

Any oil in that 3.8 pipe will become hard to push into the accumulator and so keep most oil in the engine.

The Yanmar 6LP has piston coolers , that is jets of oil. The pump is of high volume.

Remember at the present time I have no oil in my filter or presumably the galleries, it is an absolute dry start. Pressure injecting 1 quart of oil would be helpful at any speed it likes. I expect to wait 5--6 seconds and see the alarms go off.

If you take advantage of my links on the prelube site there is a boat with 2 Yanmar 6 LPs with the system on it, read what the owner says.

I don't see it written anywhere that the accusump is anything different than the autoprelube.

Finally again for those that fabricate thier own information,-- please for the last time it does "not" rattle when the engine starts, this is getting stupid and tedious and is not helping your reputation as a worth while poster.

If you don't use smilies I cant tell if your yanking my chain or you really cant read and believe this wont work.

But then you think it may not work As you technically explained [I might get lucky and it might work.]

I would be delighted to have this discussion on this simple technology that is becoming more and more used in engines that stand unused for long periods.

 

Lets take this on one item at a time, and then I'm done....

You aren't listening. Oil won't rush into the tank first, it will flow from the pump to the gallery, but without a small restriction between the tank and the gallery, the pressure in the gallery will be the same as that of the tank. The tank pressure does not instantly come up, it takes oil volume to raise the pressure in the tank. To get 15 psi in the tank and gallery, with a two quart tank it will take about a quart of oil in the tank. How much oil does it take to fill the gallery and filter? If you guess about a quart, you are probably close, I doubt it is more than 2 quarts.

Right, so lets assume that the tank is now empty.

Wrong! If you were in a fluids class you would have just failed… If the tank is preloaded NO oil will flow into the tank until the preload is overcome. This is a key difference. This feature lets the bearings get to pressure and insures a minimum pressure in the gallery before flow is siphoned off to fill the tank. I have tried to explain this a couple of times, but you just don't seem to get it. This is the last time I will try…

The autoprelube siphons off oil continuously as the pressure in the gallery rises. The accusump does not. At startup, when the entire lube system is full of oil (and the reservoirs are empty) if you plotted pressure versus time and compared the two pressure curves you would see that the system with the accusump would have an instant step in pressure to the preload pressure value, then pressure would increase to the normal idle pressure over a period of time following a curve based on the method of tank pressurization. With a simple unrestricted tank, the pressure will rise from zero to the full delivery pressure in essentially a parabolic curve, starting at zero, with a time constant based on the time required to fill the tank. The time at low pressure will be minimal with the accusump. With an unrestricted tank system you will have a slower ramp up of pressure and it will start from zero.

The accumulator is attached to the gallery, the relief valve has nothing to do with this. It is closed all during this time. Assuming that the accumulator is between the oil pump and the bearings, the oil flow will split to the path of least pressure. Unless you know the jet areas and bearing areas, you have no idea which way the oil is going to flow.

Your lungs can develop about 1.5 psi, or essentially nothing, and blowing air is totally different than increasing pressure via volume displacement, so your blowing into the tank analogy is not relevant.

As I said, it takes a quart of oil to get 15 psig in a two quart tank. A pint of oil will raise the pressure in the tank to about 3.5 psig. Simple pressure volume relationship. If it took 12 seconds to fill a filter and gallery (about a quart), then your flow rate is about 1 gpm. I doubt it is that low, but it can't be more than 2 gpm at cranking and idle. Big block Chevy racing engines at full power flow between 10 and 12 gpm, so this estimate is probably not that far off. If half the flow went to the tank (which you don't think will happen) the flow rate in the 3/8ths pipe is at most 1 gpm. At 1 gpm or less a 3/8ths pipe is no restriction at all. Get on line and look at the line loss in a 3/8ths pipe. At these flow rates you aren't going to have any measurable line loss. Unless you restrict the flow to the tank, you are going to need something on the order of 5 to 6 seconds to build measurable pressure (more than 3.5 psi) in the gallery. This is assuming that half the oil is flowing to the gallery and half to the tank up to 3.5 psi. With oil jets it may be longer because so much is flowing out the jets. You’re supposed to be an engineer, you could have figured this out, it isn't rocket science.

What is high volume? At what RPM? You have no idea other than the estimate that I just made as to the pump capacity, which is not a lot at these low speeds. Piston coolers just mean that more oil will go out the jets before you get bearing pressure.

I don't know at what pressure the alarms go off at, if it is 15 psi, you will wait a lot longer than that. If it is 3-5 psi, you may be close. Not having the bearings dry is going to be an improvement, but if your goal is to get good oil pressure to the bearings unless you restrict the flow to the tank it may not do what you want. This is the crux of what I have been trying to say.

That is an engineered system with proper orifices in it that could make a huge difference in the way it performs as compared to the jury rig system that you were talking about building yourself.

See the note above about preload, it is clearly different. You are simply not listening or don’t want to understand the difference.

I think everybody here can judge who is listening or trying to be serious.

The relationship is indeed simple, it’s called the relationship between volume and pressure, and unfortunately you don’t seem to get it.

I’m done with trying to help you.

 

Right then, "rolls up sleeves" I have read everything on Accusump. there are some issues here.

Accusump is primarily a pressure stabalizer for racing applications of cars loosing oil pressure round corners ,--waiting at traffic lights etc. Oil surge protector.

The pre lub is a simple system . The cannister has to be upright to work not like the accusump.

My goal is not or ever has been to get good oil pressure in the system before firing, you know that. I will be happy if I get no alarm and a simple guage movement.

The pre lub can aslo be precharged by a schrader valve in the top of the cylinder. For pre lubing once every 3 months it will be fine.

When I get used to the system I will be able to flick the switch to absorb the oil pressure at my liking. And if you like I can turn the valve off as soon as it fires and slowly milk in the pressure watching the guage rise.

I have located 2 carbon fibre co2 fire extinguisher pressure cannisters that look identical to the prelube system.

Carbon firbe --nice.

If I cant get any answers from Yanmar on why my filters drain I have to stand on my own two feet, stop crying and get myself out of the ****.

Criticism that it "may not work" will not deter me. Sitting in front of the fire with my slippers on writing cheques to Fedex and ebay is not my way.

I designed and built my own surface drives and deep sea seals that have been trouble free for years(forgot about the seals) they work better and more efficient then the manufacturers does with 100HP less.

I think I can make a little luber system that will help dry starts on my Crap Yanmars.

But please (hands clasped together) please continue with your constructive criticism.

 

So, if Yamnars are crap, what are Sramnay's like? maybe a backwards Yanmar will be a step forward? I can remember stories of used car salesmen used to put bananas in the sump to stop some of the noise in that area... does that work?

 

hello mas what you doing here?