oil pressure question

[Ajwash]

I have a 1961 ford 4000 industrial loader backhoe, what should the oil pressure gauge read? right now with a warm engine the gauge reads around 30 at idle and when throttled up with no load the gauge maxes out at 80.

 

[Bern]

I think most people with a tractor that old would be delighted to have 30 PSI at hot idle. 80 sounds a little high, but nothing to get too excited about.

 

[Rusty_S85]

Rule of thumb you only need a min of 10 psi per 1000 rpm. So at 30 psi at a 500 rpm idle for instance is good up to 3000 rpm.

 

[Bern]

I'm not liking your "rule of thumb". Allowing 20 PSI at 2000 RPM is asking for trouble.

 

[Rusty_S85]

(quoted from post at 21:17:49 05/10/16) I'm not liking your "rule of thumb". Allowing 20 PSI at 2000 RPM is asking for trouble.

Well don't, but GM, Ford, and even Chrysler did this test and found out for any engine be it a race engine or a stock engine 10 psi per 1000 rpm is safe. Anything more than 10 psi per 1,000 rpm is putting extra load on the dist to spin the oil pump resulting in more stress on the dist/oil pump as well as higher fuel consumption.

But if you don't want to follow it, don't. But the whole automotive world knows of this rule of thumb for oil pressure.

 

[Bern]

The original poster did not mention whether his engine is gas or diesel, but I'm leaning towards diesel if it's a backhoe. This being the case, there's no way your rule of thumb will work in a diesel. Semis are motoring down the highway today at 1200 RPM. They wouldn't last an hour with 12 PSI of oil pressure.

 

[Rusty_S85]

(quoted from post at 22:17:23 05/10/16) The original poster did not mention whether his engine is gas or diesel, but I'm leaning towards diesel if it's a backhoe. This being the case, there's no way your rule of thumb will work in a diesel. Semis are motoring down the highway today at 1200 RPM. They wouldn't last an hour with 12 PSI of oil pressure.

Diesels actually have two stages to the oil system, they have a high volume system that is also high pressure and they also have a low pressure system which is just like a gas engine. This low pressure system delievers oil to the high volume pump to provide high volume and pressure where it is needed such as oil driven fuel injectors. But besides that, diesel engines still have the same oiling system as a gas engine.

As I said you don't want to believe this rule of thumb that is known in the automotive world don't, but don't try to be patronizing to someone that actually works in the automotive field and knows about the internal workings of diesel and gas engines. A diesel engine is no different than a gas engine, the main difference is a diesel engine has no ignition system as it uses compression to fire the cylinders. Besides that the crank, and rods, and pistons don't know they are in a diesel engine or a gas engine and oil is still supplied to cool and lubricate which even at 10 psi at 1000 rpm is still able to provide this function.

Its like the crowd that thinks for a performance engine you need a high volume high pressure oil pump but yet talk to the real engine builders they will tell you it does nothing but cause excessive load and wear and tear on your engine turning that kind of pressure. Plus oil pumps have a internal pressure regulator once pressure reaches the preset anything over will be dumped back into the oil pan thus negating the purpose of lubricating the engine.

 

[Ajwash]

So should I be concerned with the gauge being maxed out or is this normal? Gas engine by the way.

 

[showcrop]

(quoted from post at 22:25:06 05/10/16)

(quoted from post at 22:17:23 05/10/16) The original poster did not mention whether his engine is gas or diesel, but I'm leaning towards diesel if it's a backhoe. This being the case, there's no way your rule of thumb will work in a diesel. Semis are motoring down the highway today at 1200 RPM. They wouldn't last an hour with 12 PSI of oil pressure.

Diesels actually have two stages to the oil system, they have a high volume system that is also high pressure and they also have a low pressure system which is just like a gas engine. This low pressure system delievers oil to the high volume pump to provide high volume and pressure where it is needed such as oil driven fuel injectors. But besides that, diesel engines still have the same oiling system as a gas engine.

As I said you don't want to believe this rule of thumb that is known in the automotive world don't, but don't try to be patronizing to someone that actually works in the automotive field and knows about the internal workings of diesel and gas engines. A diesel engine is no different than a gas engine, the main difference is a diesel engine has no ignition system as it uses compression to fire the cylinders. Besides that the crank, and rods, and pistons don't know they are in a diesel engine or a gas engine and oil is still supplied to cool and lubricate which even at 10 psi at 1000 rpm is still able to provide this function.

Its like the crowd that thinks for a performance engine you need a high volume high pressure oil pump but yet talk to the real engine builders they will tell you it does nothing but cause excessive load and wear and tear on your engine turning that kind of pressure. Plus oil pumps have a internal pressure regulator once pressure reaches the preset anything over will be dumped back into the oil pan thus negating the purpose of lubricating the engine.

Rusty, Bern has credentials here.

 

[Larry NCKS]

(quoted from post at 23:38:36 05/10/16)

(quoted from post at 21:17:49 05/10/16) I'm not liking your "rule of thumb". Allowing 20 PSI at 2000 RPM is asking for trouble.

Well don't, but GM, Ford, and even Chrysler did this test and found out for any engine be it a race engine or a stock engine 10 psi per 1000 rpm is safe. Anything more than 10 psi per 1,000 rpm is putting extra load on the dist to spin the oil pump resulting in more stress on the dist/oil pump as well as higher fuel consumption.

But if you don't want to follow it, don't. But the whole automotive world knows of this rule of thumb for oil pressure.

Funny, I've never heard of this "rule" before! I'm with Bern. If my semi engine (Detroit 60 series 14.0L) was only putting out 15 psi running down the road loaded at 60 mph, I'd be taking it to the doctor!

 

[maxwell99]

You need to check you manual for the proper oil pressure,
Different vehicles require different oil pressure levels,
I had a 1957 D14 AC tractor that ran about 15psi oil pressure, I put a 60 pd gauge on it and had no oil pressure, that is when I checked for
proper oil pressure and replaced the gauge with a 30 psi gauge, oil pressure looked much better on that gauge,

As I understand it when dodge started placing the Diesel engines in there pickups people were coming in right and left complaining about low
oil pressure at idle, 10-15 psi, yet at speed the oil pressure came up,
Finally to compinsate for owners not used to diesel motor operations, they just added some type device that shows a higher oil pressure on the
gauge at idle so not to excite the new diesel motor owners,

(Do not know if this story is true or not, but I look at the oil gauge in my dodge diesel truck each day and wonder if the good pressure I am
seeing is really the correct oil pressure of the motor)

 

[Bern]

There's a simple solution to this argument....call Cummins sometime (or Cat, Detroit, Mack, JD, or the diesel engine manufacturer of your choice), and ask them if 10 PSI oil pressure is adequate for an engine that is working at 1000 RPM. Then ask them if 20 PSI is OK for an engine working at 2000 RPM. They will all say without a doubt: "H-e-double-toothpicks no!".

Engine builders today are trying to squeeze every last drop of fuel economy from today's engines, and you're right, excessive oil pressure works against that goal. However, they aren't going anywhere near your "rule of thumb". As an example, minimum oil pressure spec for a Cummins ISX (the most popular semi-truck engine on the road today) is 35-40 PSI at working speeds. Working speeds are around 1500 RPM.

As for there being no difference between gas and diesel, consider that a diesel operates with far greater internal forces than a gas engine, especially on the power stroke (i.e. torque). I'd argue that while adequate oil pressure is important in a gasser, it's even more important in a diesel.

I would agree with you that engines don't benefit from excessive oil pressure, however, as I said earlier, suggesting that 20 PSI @ 2000 RPM is OK is dangerous advice. Many OEMs would seem to agree with me.

 

[Bern]

Best answer there is to screw in a known-accurate mechanical hand-held gauge and compare. If it really is 80 PSI max, I would leave it. Much more than that and I'd be pulling the pan and looking at the relief valve.

 

[KV Bruce]

This topic makes for good reading in the morning. A wise man (can't remember his name) once said "can't we all just get along?" My 3400, gas runs 35 psi at idle and 55 at 1500 rpm. If you don't really trust the gage, replace it with a known good one.

 

[souNdguy]

He's exceeding the relief by a good bit. Unless he's running something like 50w straight oil.. I'd for sure be checking that gauge.

On some of my tight gasser red tigers, on 15-40 oil on a cool morning at high throttle just at startup I can make 65 psi for a a short period of time before things warm up to a point that 55 is max.

I have some later and much later diesels that can make 80.. but that aren't that old red tiger..

 

[souNdguy]

I'd check it with another gauge to be sure.

also, what oil are you running?

 

[Rusty_S85]

(quoted from post at 05:50:34 05/11/16) There's a simple solution to this argument....call Cummins sometime (or Cat, Detroit, Mack, JD, or the diesel engine manufacturer of your choice), and ask them if 10 PSI oil pressure is adequate for an engine that is working at 1000 RPM. Then ask them if 20 PSI is OK for an engine working at 2000 RPM. They will all say without a doubt: "H-e-double-toothpicks no!".

Engine builders today are trying to squeeze every last drop of fuel economy from today's engines, and you're right, excessive oil pressure works against that goal. However, they aren't going anywhere near your "rule of thumb". As an example, minimum oil pressure spec for a Cummins ISX (the most popular semi-truck engine on the road today) is 35-40 PSI at working speeds. Working speeds are around 1500 RPM.

As for there being no difference between gas and diesel, consider that a diesel operates with far greater internal forces than a gas engine, especially on the power stroke (i.e. torque). I'd argue that while adequate oil pressure is important in a gasser, it's even more important in a diesel.

I would agree with you that engines don't benefit from excessive oil pressure, however, as I said earlier, suggesting that 20 PSI @ 2000 RPM is OK is dangerous advice. Many OEMs would seem to agree with me.

Oil press works against flow. You reach a certain point past what is required to get oil to where it needs excessive oil pressure starts to restrict the flow. Flow is what you want and at 10 psi oil will get to where it needs to be the flow of the oil is what protects the engine.

I did a simple search on 10psi per 1000 rpm and found page after page of results on this. Its obvious the members here rather disagree and fight over providing help.

Thats fine, this is the reason why i have so few posts on here is when i have a genuine question it takes days if not weeks to get an answer. Then theres thoses questions where i am advised to rig my tractor up like some back water farmer. That goes against everything ive been trained to do in the field i work in.

So as ive said three times now believe it or dont i really dont care but dont try to convince me to believe different when I work with engines on a daily basis.

 

[Rusty_S85]

And as far as diesel engines goes new 6.7s are running 5w30 oil vs the more common 15w40 oil. This thinner oil results in lower oil pressure. But oh wait diesels need super high oil pressure to run.

 

[sotxbill]

With diesel engines with oil driven injectors having completly different requirements,,

YES... The industry is moving to lower oil pressure and lighter oils that are BRANDED and certified to produce a minimum of 2% or more in fuel economy with out increasing wear over conventional xx-40w oils. 5w30 and 5w20 oils are becoming the norm in NEW engines. And yes the oil pressure rule is out there. Additional oil pressure over whats is required, is wasted energy and non productive. So... lower pressure and thinner oils are the norm, BUT higher volume pumps may be at play here.


HOWEVER... in old engines, especially engines that have run oils from the 60s and 70s that were NOT good oils and have more wear, and NO oil coolers, and sludge build up,, I dont think I would be in a hurry to change to a thinner oil. Fuel economy is not nearly as important as keeping worn bearings lubricated and a lubrication barrier between excessive clearances.

In this case of high oil pressure, I would suspect the gauge first,,, and or blocked oil passages, and or bad relief valve. Or maybe running tar (cheap oil that has broken down) or 90 weight oil instead of fresh clean 15w40.

 

[Rusty_S85]

(quoted from post at 07:57:26 05/11/16)


With diesel engines with oil driven injectors having completly different requirements,,

YES... The industry is moving to lower oil pressure and lighter oils that are BRANDED and certified to produce a minimum of 2% or more in fuel economy with out increasing wear over conventional xx-40w oils. 5w30 and 5w20 oils are becoming the norm in NEW engines. And yes the oil pressure rule is out there. Additional oil pressure over whats is required, is wasted energy and non productive. So... lower pressure and thinner oils are the norm, BUT higher volume pumps may be at play here.


HOWEVER... in old engines, especially engines that have run oils from the 60s and 70s that were NOT good oils and have more wear, and NO oil coolers, and sludge build up,, I dont think I would be in a hurry to change to a thinner oil. Fuel economy is not nearly as important as keeping worn bearings lubricated and a lubrication barrier between excessive clearances.

In this case of high oil pressure, I would suspect the gauge first,,, and or blocked oil passages, and or bad relief valve. Or maybe running tar (cheap oil that has broken down) or 90 weight oil instead of fresh clean 15w40.

 

[Dalex]

"Motorist" Rodney King after the LA riots ....He died of a drug od years later .

 

[Bern]

Hey there Rusty....have you called Cummins yet? If so, what did they say? If not, are you afraid to hear what they'll tell you?

You seem rather upset that we'd rather "disagree and fight over providing help". I'm sorry, but you're not much help implying to Larry that his series 60 Detroit would be "just fine" running 15 PSI at 1500 RPM in his semi. If Larry were to believe you and keep on running his engine down the highway at 15PSI, he'd be buying a crankshaft (and a whole lot of other parts) in a short period of time. Then, he'd be REALLY upset. So, what's more important here, that guys like me let your advice stand and keep a smile on my face, or correct an obvious error? You can't make a blanket statement like what you did for all engines.

I'm not trying to be a puncture wound here Rusty, I'm simply trying to tell you that your "rule of thumb" would make Cat, Cummins, Detroit, Mack, JD, International, Volvo, Mercedes, Ford, and on and on, CRINGE. And if you don't believe me, then call any one of them. I dare you.

 

[Bern]

The 6.7L Fords do not need "super high oil pressure" to run. The 7.3L and 6.0L engines did, but not the 6.4L or 6.7L Fords.

 

[Rusty_S85]

(quoted from post at 10:45:42 05/11/16) The 6.7L Fords do not need "super high oil pressure" to run. The 7.3L and 6.0L engines did, but not the 6.4L or 6.7L Fords.

The high oil pressure needed in 7.3 and 6.0 and 6.4 you do know the 6.4 still is a oil driven injector system right guess not since you are lumping the 6.4 and 6.7 together. Havent seen too many 6.7s with problems come in other than basic oil changes so I don't know if they are operated the same way.

But heres the thing, the high oil pressure is only on the high volume pump side of the system. That does not lubricate the engine which is what we are talking about. Quit comparing tomatos to oranges. Fact is they all have the same low oil pressure for lubrication of the engine which is what was being discussed, the high pressure system is fed by the low pressure oiling system which then drives the injector systems but does not lubricate the engine.

As far as calling cummings, have you bothered to even do a internet search for "10psi per 1000 rpm". Like I thought you did not because theres a lot of articles about the tests done that stated this is the ideal pressure needed for an engine. As far as me calling cummings goes, I am not going to do that as I have heard lies come from dealerships when you ask them for information. It is batting 100% on that when we call in to seek specs for something that alldata and identifix does not list yet.

 

[Tiger Joe]

the 10 per 1,000 rpm rule of thumb comes from Smokey Yunick and his racing history with small block chevy engines

 

[Rusty_S85]

Like wise you do comprehend that as oil pressure goes up oil volume goes down right? When oil volume goes down that now means the oil is not cooling nor lubricating the engine as it should.

High pressure is not always a great thing. That is where the 10 psi per 1000 rpm comes in. You can operate an engine off 10 psi of oil pressure at 1000 rpm driving down the road towing a load because you still have the volume of oil lubricating the bearings and cooling the bearings. Now take and put a thicker oil in and bumps the oil pressure to 70 psi at 1000 rpm, now you have reduced your oil volume and now your oil is not cooling nor lubricating the bearings as efficiency as it could be.

 

[Rusty_S85]

(quoted from post at 10:52:54 05/11/16) the 10 per 1,000 rpm rule of thumb comes from Smokey Yunick and his racing history with small block chevy engines

Yes, and Chevrolet as well as others have done testing on his rule of thumb and found that there is truth to it. Lower oil pressure means more volume which means more oil is being applied to the bearings for lubrication and cooling.

But there is a down side to this, down side is too much flow and you have erosion of the bearing surfaces but this does not happen till you start hitting 6,000 rpm or higher with the use of a high volume oil pump. Running a thinner oil for lower oil pressure and naturally higher oil volume would not result in bearing erosion.

This all stems from the race track which is where all engine advances have came from when it comes to efficiency.

 

[Rusty_S85]

And sure we are talking about tractors not high speed high performance race engines, but a engine is an engine and 80 to 90 percent of engine wear starts at start up. Oil is cold and does not want to flow which results in oil quickly hitting the pressure regulator limit of the pump and gets bypassed back to the pan vs going to the mains and the bearings.

Thinner oil how ever will flow better when cold but you have to find a good balance between cold flow capabilities as well as good hot flow. Tractors of the 50s and 60s be it diesel or gas called for in 40* or warmer weather to run straight 30 weight oil. I run 20w50 in my gas as its a flat tappet non hydraulic cam and in the diesel I run 15w40 diesel oil for the better cold flow vs straight 30 weight. This reduces pressure when cold as well as hot but not so much that it will harm the engines.

 

[Bern]

Agreed, 80 PSI is on the high side. However, it would not be enough for me to fret about and make me pull the oil pan. I can think of funner and more productive things to do.

 

[souNdguy]

Oil pan? Naaa, not untill I had a reference gauge on it and saw what it did thru a range of rpms and temps.

If it settled to anywhere near relief pressure on a warm throttle, I'd be ok with it.

That's also assuming not some odd oil like straight 50, or a crank as full of stp ir Lucas stabilizer.

 

[souNdguy]

Agreed, you can't blanket statement this stuff.

When I got my case vac, I thought it had low oil pressure (20 max rpm ) till I read the manual and saw it was designed for pressures around 22 and lower.

Lots different than this red tiger gasser, a power stroke, or a big truck engine.

I'm with Bern, check the gauge and state what oil is being ran, go from thete

 

[Bern]

Rusty,

You are all over the place here - where do I even start...

First off, the 6.4L engine uses the common rail fuel system, not the HEUI fuel system, so you are incorrect there. If you wish to call me argumentative and unhelpful, I'm sorry, but I have to correct your mistakes.

Second, I was never talking about the high pressure injection system to start with. YOU are the one who brought it up, not me. I've been talking about the low pressure lubrication system all along.

Third, it's "Cummins", not "Cummings".

Fourth, you don't wish to call Cummins because you say that the dealerships will lie to you. OK, I'll buy that, dealership personnel have been known to lie. How about we do one better, and go straight to the Cummins service manual?

I hope the attached screen shot from Cummins QuickServe, the official Cummins service manual, will put your theory to rest, at least for diesel engines. As you can clearly see, Cummins wants a minimum of 25 PSI @ 1200 RPM on the N14 (a very popular truck engine), which is over twice what your "rule of thumb" calls for.

Sure, I could get on the Google and do the search you requested. However, I always turn my "BS filter" way up whenever I do so. If there's one thing I've learned in my long career, it's that it's almost ALWAYS better to trust the OEM over someone you don't know on the internet.

 

[Bern]

"Lower oil pressure means more volume which means more oil is being applied to the bearings"?

Really?

 

[Rusty_S85]

Wrong on the 6.4. Have one in the shop right now that has low volume pressure but no high volume pressure. It will not run without high volume pressure as it is not a common rail system. That came in the 6.7 the 6.0 and 6.4 are nearly identical.

As far as trust goes, you must have a hard life to sit and be a internet warrior. You think im lying go ahead i dont care but you sure seem to be going out of your way to prove what i said is wrong. In doing so youve made it clear to me you dont know what you think you do especially with the manure claim the 6.4 and 6.7 are common rails even though i have one torn down at work that is a 6.4 that needs a high volume pump.

Now as far as lower pressure equals more volume its true. Thats why lighter weight oil results in not just lower oil pressure but more oil thrown on the cylinder walls. Can get to be so much that it could overwhelm the rings and result in burning oil and smoking.

 

[Larry NCKS]

(quoted from post at 12:52:26 05/11/16) cummings.

Sorry! But that word right there tells me a lot about your credibility here!

 

[Larry NCKS]

(quoted from post at 15:41:57 05/11/16) "Lower oil pressure means more volume which means more oil is being applied to the bearings"?

Really?

Yeah! You betcha! It just gets there a day late and a few thousand dollars short! :lol:

 

[showcrop]

(quoted from post at 14:32:37 05/11/16)
Wrong on the 6.4. Have one in the shop right now that has low volume pressure but no high volume pressure. It will not run without high volume pressure as it is not a common rail system. That came in the 6.7 the 6.0 and 6.4 are nearly identical.

As far as trust goes, you must have a hard life to sit and be a internet warrior. You think im lying go ahead i dont care but you sure seem to be going out of your way to prove what i said is wrong. In doing so youve made it clear to me you dont know what you think you do especially with the manure claim the 6.4 and 6.7 are common rails even though i have one torn down at work that is a 6.4 that needs a high volume pump.

Now as far as lower pressure equals more volume its true. Thats why lighter weight oil results in not just lower oil pressure but more oil thrown on the cylinder walls. Can get to be so much that it could overwhelm the rings and result in burning oil and smoking.

Rusty, in addition to your above areas of lack of understanding, you are also a little short on knowledge of fluidics. I don't claim to be an expert but I can see where you misunderstand. In addition to an adequate pump, in order to get pressure you need restriction. You can have a pump that is capable of producing 100 lbs under normal conditions, but if you set it up so that it is pumping directly into an open atmosphere, it will not develop one pound of pressure. Oil pressure does not drive volume down as you stated. RESTRICTION will raise pressure and reduce flow. If there is not high flow to be impeded by restriction there will be very little pressure developed. Any beginner firefighter has to learn all of this. True, a thinner oil will pass through the restrictions better, but water, gasoline or fuel will not lubricate either. Rusty you have a lot of knowledge, but there are holes in you knowledge, and as I posted earlier, Bern has credentials here, which have been earned over many years and thousands of knowledgeable posts, helping many members here. You can't get out of this hole you are in unless you quit digging.

 

[Rusty_S85]

I know how to solve this real quick, I am digging a hole even though the person in question is stating false information as fact. I see where the loyalties lie and I am not going to hang around to deal with this manure.

I come on here for hard to answer questions I have and the kind of answers I get so far to this point has not been sastifactory to what I am seeking. I am still to this point waiting on someone to notify me of the part number or where to buy the power steering filter. But no one has decided to answer that question but boy are people quick to recommend rigging up a tractor vs fixing it properly.

So after all this drama which by the way was started and continued on by the liar that you are all defending I have to say I am through with this place. Should have never joined this place as Ive gotten more help from the clueless people at Napa than on here.

So have fun everyone, keep spreading false information and living in the past when it comes to the mechanical field.

 

[Bern]

Rusty,

Did I ever call you a liar? NO! A liar is someone who spreads false information INTENTIONALLY, and I do not believe that you have done so. I simply said that you stated some things that were in error. The 6.4L engines as used in the 2008-2010 Ford F-series pickups ARE IN FACT common rail, as is the later 6.7. The earlier 7.3 and 6.0L engines are in fact HEUI engines. I challenge you to prove me wrong here. Trust me, if I were wrong, someone here on this board would correct me, you can be sure of that.

On the flip side, you call ME a liar, when I provide evidence from the #1 builder of diesel engines that I am correct, and that your "rule of thumb" is wrong. Something is really wrong with that Rusty. Now, this normally wouldn't be that big of a deal, but when you make a blanket statement the way you do about oil pressure, someone might believe you and choose to ignore low oil pressure in their engine. If they do, they could spend thousands of dollars more than they need to to fix the problem.

Again, I'm really not trying to be a jerk here. I'm simply trying to correct the record. I show manufacturer's specs, and you point me to the internet. Sorry, but I'll trust the engine manufacturer over someone else's opinion.

 

[Rusty_S85]

(quoted from post at 18:54:34 05/11/16) Rusty,

Did I ever call you a liar? NO! A liar is someone who spreads false information INTENTIONALLY, and I do not believe that you have done so. I simply said that you stated some things that were in error. The 6.4L engines as used in the 2008-2010 Ford F-series pickups ARE IN FACT common rail, as is the later 6.7. The earlier 7.3 and 6.0L engines are in fact HEUI engines. I challenge you to prove me wrong here. Trust me, if I were wrong, someone here on this board would correct me, you can be sure of that.

On the flip side, you call ME a liar, when I provide evidence from the #1 builder of diesel engines that I am correct, and that your "rule of thumb" is wrong. Something is really wrong with that Rusty. Now, this normally wouldn't be that big of a deal, but when you make a blanket statement the way you do about oil pressure, someone might believe you and choose to ignore low oil pressure in their engine. If they do, they could spend thousands of dollars more than they need to to fix the problem.

Again, I'm really not trying to be a jerk here. I'm simply trying to correct the record. I show manufacturer's specs, and you point me to the internet. Sorry, but I'll trust the engine manufacturer over someone else's opinion.

Well you are calling me a liar. I tore down a 6.4L diesel for a high volume pump the same high volume pump found on a 6.0. It would not start because it had low volume oil pressure but not high volume oil pressure. The 6.4 is not common rail atleast not all of them. Maybe there were a few mid production ones that went common rail but all the ones Ive worked on used the same high volume oil pump as the 6.0. Now explain to me how could I be doing a job as per my bosses work order on a part that is not on a vehicle?

If I had access to Identifix right now I bet if I brought it up I could find a diagram easily of the 6.4 high volume system for the injectors. Another 6.4 we had just last week had a blown O ring in injector #4 resulting in drastically reduced high volume oil pressure.

In the end it doesn't matter I am through here. Life is too short and I am too old to deal with childish arguments and being treated like I am a liar or don't know what I am talking about when it comes to something I do for a living.

 

[Destroked 450]

The 850 that I grew up on held around 25-30 hot idle and 60 at pto speed hot, we used SAE30 and first cold start it would show 80 psi until it warmed up. Not sure what oil your using using but if it stays above 80 when it's at operating temp I'd think about dropping the pan and checking the relief valve.

Pressure relief on my 3 cylinder 4000 is 60-70 psi.

After reading through this thread I'm reminded of when I rebuilt my granddad's 550 Oliver, when I got it running he asked what the oil pressure was, I looked at the gauge and said 15 lbs, his remark was, well that's 3 more lbs than it had when I bought it new.

Where the gauge is connected has some affect on how much pressure you'll see. On my 5.9 Cummins if you have the gauge connected at the main oil galley near the inj pump (Dodge location) it shows 60 psi, if it's connected at the filter base (MD truck location) it shows 75 psi. The farther away from the pump the lower the pressure will be.

 

[sotxbill]

Start of wiki

Oil pressure

The oil pressure generated in most engines should be about 10 psi per every 1000 revolutions per minute (rpm), peaking around 55-65 psi.[2]

Local pressure (at the crankshaft journal and bearing) is far higher than the 50, 60 psi &c. set by the pump’s relief valve, and will reach hundreds of psi. This higher pressure is developed by the relative speeds in feet per second (not RPM or journal size directly) of the crankshaft journal itself against the bearing, the bearing width (to the closest pressure leak), oil viscosity, and temperature, balanced against the bearing clearance (the leakage rate).

All pump pressure does is “fill in the hole” and refresh the oil in the annular space faster than the leak expels it. This is why low-speed engines have relatively large journals, with only modest pump size and pressure. Low pressure indicates that leakage from the bearings is higher than the pump’s delivery rate.
Gauge pressure

The oil pressure at the pump outlet, which is what opens the pressure relief valve, is simply the resistance to flow caused by the bearing clearances and restrictions.

The oil pressure gauge, or warning lamp, gives only the pressure at the point where its sender enters that part of the pressurized system – not everywhere, not an average, nor a generalized picture of the systemic pressure.

Despite the frequent comparison to hydraulic engineering theory, this is not a “closed system” in which oil pressure is balanced and identical everywhere. All engines are “open systems”, because the oil returns to the pan by a series of controlled leaks. The bearings farthest from the pump always have the lowest pressure because of the number of leaks between the pump and that bearing. Excess bearing clearance increases the pressure loss between the first and last bearing in a series.

Depending on condition, an engine may have acceptable gauge pressure, and still only 5 psi pressure at one connecting rod, which will fail under high load.

The pressure is actually created by the resistance to the flow of the oil around the engine.[5] So, the pressure of the oil may vary during operation, with temperature, engine speed, and wear on the engine. Colder oil temperature can cause higher pressure, as the oil is thicker, while higher engine speeds cause the pump to run faster and push more oil through the engine. Because of variances in temperature and normal higher engine speed upon cold engine start up, it’s normal to see higher oil pressure upon engine start up than at normal operating temperatures, where normal oil pressure usually falls between 30 and 45 psi.[6] Too much oil pressure can create unnecessary work for the engine and even add air into the system. To ensure that the oil pressure does not exceed the rated maximum, once pressure exceeds a preset limit a spring-loaded pressure relief valve dumps excess pressure either to the suction side of the pump, or directly back to the oil pan or tank.

High oil pressure frequently means extremely high pressure on cold start-up, but this is a design flaw rather than an automatic consequence of high pressure. The observation “if you raise the maximum pressure, the cold pressure goes too high” is accurate, but not intentional.

Even the stock pumps (regardless of brand and model) do not have enough relief valve capacity: the relief port is too small to handle the volume of cold oil. This is why there is a significant difference between cold & hot oil, high & low RPM, &c., but it’s typically not a problem with stock engines. A correctly designed relief port (which is not found in production engines) will flow any oil volume the gears will pass, regardless of oil viscosity or temperature, and the gauge reading will only vary slightly.

The oil pressure is monitored by an oil pressure sending unit, usually mounted to the block of the engine. This can either be a spring-loaded pressure sensor or an electronic pressure sensor, depending on the type of sending unit. Problems with the oil pressure sending unit or the connections between it and the driver's display can cause abnormal oil pressure readings when oil pressure is perfectly acceptable.

Low Oil Pressure

Low oil pressure, however, can cause engine damage. Low oil pressure can be caused by many things, such as a faulty oil pump, a clogged oil pickup screen, excessive wear on high mileage engines, or simply low oil volume. Indications of low oil pressure may be that the warning light is on, a low pressure reading on the gauge, or clattering/clinking noises from the engine. Low oil pressure is a problem that must be addressed immediately to prevent serious damage.

The leading cause of low oil pressure in an engine is wear on the engine’s vital parts. Over time, engine bearings and seals suffer from wear and tear. Wear can cause these parts to eventually lose their original dimensions, and this increased clearance allows for a greater volume of oil to flow over time which can greatly reduce oil pressure. For instance, .001 of an inch worn off of the engine’s main bearings can cause up to a 20% loss in oil pressure.[5] Simply replacing worn bearings may fix this problem, but in older engines with a lot of wear not much can be done besides completely overhauling the engine.

Particles in the oil can also cause serious problems with oil pressure. After oil flows through the engine, it returns to the oil pan, and can carry along a lot of debris. The debris can cause problems with the oil pickup screen and the oil pump itself. The holes in the oil pickup screen measure about 0.04 square inches (0.26 cm2).[5] Holes of this size only pick up bigger pieces of debris and allow a lot of smaller pieces to flow through it. The holes in the screen are so big (relative to debris) because at low temperatures and slow engine speed the oil is very viscous and needs large openings to flow freely. Even with these large holes in the screen, it can still become clogged and cause low oil pressure. A .005-inch-thick (0.13 mm) coating on the screen can reduce hole size to about .03 square inches (0.19 cm2), which in turn reduces the flow of oil by 44 percent.[5]

Even after passing through the oil pickup screen and the oil filter, debris can remain in the oil. It is very important to change the oil and oil filter to minimize the amount of debris flowing through your engine. This harmful debris along with normal engine wear in high mileage engines causes an increase in clearances between bearings and other moving parts.

Low oil pressure may be simply because there is not enough oil in the sump, due to burning oil (normally caused by piston ring wear or worn valve seals) or leakage. The piston rings serve to seal the combustion chamber, as well as remove oil from the internal walls of the cylinder. However, when they wear, their effectiveness drops, which leaves oil on the cylinder walls during combustion. In some engines, burning a small amount of oil is normal and shouldn’t necessarily cause any alarm, whereas burning lots of oil is a sign that the engine might be in need of an overhaul.

END of wiki

So.. If one reads through it... cold high pressure is a huge problem and limits the design in one extreme... AND bearing wear means the pumps needs more capacity for longer life,, but that very design will give it more pressure than needed in early life. And relief valves are not designed large enough in current pump design to fix this over capacity design.
So we have higher oil pressures in older designs as a result.


Also.. on new vehicles, since the 100,000 mile mark is being reached and far exceeded, now mpg is more important and extending the engine life. Govenment "CAFE" Corporate Average Fuel Economy goals are pushing the required mpg requirements, so yes... thinner oils and lower oil pressures are the new design critieral.


But.. I dont know if I have seen the HD diesel world move this direction yet... I cant afford new diesels so I cant say. My 2013s still requires 5w40 or 15w40.... And the red tiger was an industrial design.

Sources.....
https://en.wikipedia.org/wiki/Oil_pump_%28internal_combustion_engine%29

 

[cdmn]

There's hydrostatic lubrication and hydrodynamic lubrication. The first is provided by the pump forcing lubricant
into the bearing. The second is developed by the journal spinning in the bearing, and is much higher than the first.
It is a fact that Fordson tractors had no oil pumps until 1952. (Since 1917, and earlier in Ford cars). The Fordson
worked, but not for long. But exchange engines were cheap. Maybe lasted 2 or 3 seasons, if worked hard. In the meanwhile,
Hudsons and Chevies came with splash lubrication until 1954. The Nash engineer preferred splash lubrication. He didn't
trust oil pumps to not pump debris into the bearings. He claimed if one bearing started pounding out, the others would not be affected. But then oil filters weren't that good back then.

 

[Bern]

http://diesel.org/nozzle/powerstroke-6-4l-engine-and-fuel-issues

Straight from ADS, the Association of Diesel Specialists. They clearly state that the fuel system is common rail.

You're right, if we can't agree on what kind of a fuel system a 6.4L Ford (International) engine has, then we might as well stop right here.

 

[Larry NCKS]

(quoted from post at 22:59:59 05/11/16) http://diesel.org/nozzle/powerstroke-6-4l-engine-and-fuel-issues

Straight from ADS, the Association of Diesel Specialists. They clearly state that the fuel system is common rail.

You're right, if we can't agree on what kind of a fuel system a 6.4L Ford (International) engine has, then we might as well stop right here.

I have a 6.4L International in my '08 Ford F-350. I'll guarantee you it has a common rail fuel system.

 

[Bern]

The article does not say anything about diesels, which, as I have maintained from the start of this conversation, will not tolerate the "10 PSI for every 1000 RPM" rule.

I will grant Rusty this much...that theory might hold out with most gas engines, but not diesels.

 

[Destroked 450]

I have a 5.9 Cummins in my 04 F-450 and it's not common rail or high pressure oil injected for a reason.
12 valve Cummins are easy to maintain and cheap to repair.

 

[ErnieD]

We bought a 851 with about 600 hours on it in the early '60's it carried 80 cold and 55-60 hot. Also had a NAA and it carried the same pressure when it was rebuilt at a Ford dealership. At the time we ran straight 40 weight Cen Pe Co oil year around; got 9000 hours on the 851 before the compression got to where it would not start. It plowed, baled and chopped forage; our "big tractor" at the time.

I have a 871 now with unknown hours, it carries 40 hot and cold. I replaced the rod's, mains, and oil pump (plastigaged the bearings and they were within spec) for what I now believe to be wrist pin knock. Just acquired a 851 with 4000+ on a non-working clock and it carries 80 hot and cold.

I do recall reading Smokey Yunick's column in Popular Science in the late '60's where he quoted 10 psi/thousand rpm for a Chevrolet engine as minimum.

We had a Ferguson TO-30 (Continental engine) that ran for years at 8 psi wide open and zero at idle. When it hit 5 psi/0 idle it would knock at idle. Filled silo 3-4 seasons with it wide open on the blower.

My personal opinion is I like to see oil pressure (hot) at least 25 at idle and 45 going at power.

 

[Hobo,NC]

Good post Thumbs up... I picked up a few thangs that will serve me well

 

[BBq-Bob]

Hey folks, on my 650, it will knock for about 5 long seconds when I first crank it up from cold. Once the oil pressure gauge needle starts to move, it quiets right down and shows good pressure.

I have no idea how many hours it has on it. Should I be worried about this knocking?

 

[Tall T]

BBqBob,

I had a '58 Austin 1500 engine that gave me 7 or 8 knocks until oil pressure was up . . . drove it for a few years and sold it about 8 years ago. AFIK it is still running fine.

Elsewhere in this thread, Rusty said that light oil would overwhelm the rings resulting in burning oil. I found the opposite with one engine. I went too heavy on viscosity too soon and the oil control/scraper rings couldn't deal with the heavier film and so it was burning oil. I cut back to a light oil and the consumption immediately ceased.

Innocent Bystander

 

[Tall T]

Bob,

Start your tractor at the lowest rpm you can get away with till you get past the knocking.

 

[Hobo,NC]

Its talking to ya... That's a fair enoufh warning for me. If were a woman then yes I would not pay any attention to it...

My question is "what do you think it trying to tell ya"

 

[NoNewParts]

agree with Hobo.....stage 2 conversation

stage 1, an erratic gauge or just a whisper of a strange noise from your engine. "What [i:da29ac8850]is[/i:da29ac8850] that?"

stage 2, in a calm clear voice, your engine is asking for your assistance

stage 3, In a loud, frantic voice, your engine is yelling for your help.

stage 4, silence, as you are sadly loading your deceased engine into your truck to go to the scrapyard.

 

[Tall T]

About the faint knock . . .
Don't get me wrong, it bothered the heck out of me. As you know I am a mechanical worry wart about the slightest thing.

I was just saying that if you baby it, you can use it [b:3220000272]until you get around to rebuilding or dealing with the offending rod[/b:3220000272], which should be your ultimate intention.

In my case, I sold the car cheap to a couple who came all the way out from Alberta to trailer it home. They wanted it because they had gotten married in the identical car. And yes, I told them about the faint, muted knock which they couldn't even hear.

So don't go telling me I have the mechanical sensibilities of a woman. That is if you don't want me thinking that people here relish the chance to subtly call someone a fool.

 

[Hobo,NC]

(quoted from post at 23:11:22 05/14/16) About the faint knock . . .
Don't get me wrong, it bothered the heck out of me. As you know I am a mechanical worry wart about the slightest thing.

I was just saying that if you baby it, you can use it [b:4304d29fa2]until you get around to rebuilding or dealing with the offending rod[/b:4304d29fa2], which should be your ultimate intention.

In my case, I sold the car cheap to a couple who came all the way out from Alberta to trailer it home. They wanted it because they had gotten married in the identical car. And yes, I told them about the faint, muted knock which they couldn't even hear.

So don't go telling me I have the mechanical sensibilities of a woman. That is if you don't want me thinking that people here relish the chance to subtly call someone a fool.

If that post was directed to me I wuzz not talk'N to you... If you feel I wuzz then so be it and think whut you may I could care less...

 

[Tall T]

Hobo,

O.K. I believe you.
No big deal.
I've always found you to be helpful and respectful.

T

 

[Hobo,NC]

8)

 

[BBq-Bob]

Good info. I will start budgeting for a rebuild. That is if I can get the hydraulics right. Waiting on delivery of a 2500 psi pressure gauge currently. Thank you. Didn't know if the noise was typical or no.