lowest oil pressure for engine to survive

[alanwoodieman]

1942 Mercury engine, starts out with good oil pressure 50#, slowly decreases to about 15# as it is being driven, 20w50 oil, added some lucas extender and op went to 18# driving. Worn bearings? bad oil pump? bad relief spring? other wise runs great. no blowby. oil pressure was done with mechanical gauge

[David J]

Not really an answer to your question but those readings are quite good for a used 33-34 motor . NO CAM BEARINGS 32-34 and that does not help oil pressure .

[Mart]

You don't say about the age or condition of the engine, or your intended usage.

If an older higher mileage motor and you're not going coast to coast those figures sound ok to me.

The 59a in my truck and my crusty flatty both have similar or lower numbers than that.

Mart.

[G.M.]

That sounds about right for 20/50 when it warms
up. You are going to get "stories" of 3 or 4 lbs is
OK but don't believe them. It takes a fair amount
of oil to get a good flow into the bearings. A good
flow also cools the oil when it splashes off the crank
shaft. With an oil temp gauge on an open highway
you can watch the oil temp go up as the engine works
going up hill and cool down as it comes back down hill.
Had fun watching it in my motor home on long trips. G.M.

[rockfla]

I'm fighting sort of the "same" issue.......I'm running straight 40 here in Florida and this is strictly going by the pressure gauge on the car as I have not plumbed in a manual gauge at the block YET!!! SO that would be my first suggestion is to plumb a manual gauge at the block for a more confirmation and possibly accurate information. My next move is on the "next" oil change, drop the pan and maybe work the spring in the oil pump to see IF it will increase the pressure any OR possibly go to a higher pressure pump!!! Mine starts out at around 20lbs but once warm and running I get about 7ish going around 45 -50mph and "0" at idle!!! It runs spectacular!!! We have a "long time" friend who has been an engine mechanic going on 60 years now and as he told us a long time ago...."IF" its running good and has oil pressure when you are "rolling" down the road, run it till you either "have" to pull it OR until you can afford to pull it and rebuild it!!" SO following others comments and or suggestions here!!!

[51504bat]

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I've always heard 10 pounds per 1,000 RPM. Don't know if that's just some old wives tale or not. I do know that I had an 8ba in a '40 big truck and when it got warm it had 10 pounds or less at warm idle. Didn't have it long enough to really know how the low idle pressure affected engine life but it made me nervous looking at the gauge at warm idle.

[Talkwrench]

are you talking at idle and hot? you should be closer to 60 on start up but its not bad, I think the main thing is when you rev you see the oil pressure go up.

[deuce_roadster]

It could be a combination of all the things you mentioned. How many miles on the motor? If this is an older or un rebuilt engine it could have run a significant number of miles with old parafin based crap oil and just have a lot of wear. If it runs quietly I wouldn't worry.

[Brendan]

i used to work in a Body shop in High School, they has a 1964 Ford F350 Tow Truck with a 292, on a cold start it would have 50 lbs, after it wormed up the gauge would drop to 0 lbs. there was oil flow because it did that for a long time

[Ronnieroadster]

Its best to have at least 10 pounds of pressure per 1000 RPM. Theres certainly an issue inside the engine however what on your list is causing the issue is impossible to pick. A low reading like you have will work fine around town since your not really turning very high RPM. Just go easy until the cause is determined which will mean getting inside the engine.

[flatheadmurre]

Since you get a higher reading at start relief spring is probably ok...what you lack is flow.
So either worn so flow needed is higher then pump can deliver when hot...or pump worn.
A new pump may take you up to a level you can push on for a few more years...

[alanwoodieman]

there is a mechanical gauge on engine and the old electric gauge ran about the same pressure at the same time frame. think we need to pull oil pan and inspect the pump for wear and plastigauge the mains. the engine is of unknown mileage/lineage, runs smooth, does not over heat more than normal, good compression, good vacuum reading. relief spring is under intake.

[G.M.]

Originally Posted by rockfla

I'm fighting sort of the "same" issue.......I'm running straight 40 here in Florida and this is strictly going by the pressure gauge on the car as I have not plumbed in a manual gauge at the block YET!!! SO that would be my first suggestion is to plumb a manual gauge at the block for a more confirmation and possibly accurate information. My next move is on the "next" oil change, drop the pan and maybe work the spring in the oil pump to see IF it will increase the pressure any OR possibly go to a higher pressure pump!!! Mine starts out at around 20lbs but once warm and running I get about 7ish going around 45 -50mph and "0" at idle!!! It runs spectacular!!! We have a "long time" friend who has been an engine mechanic going on 60 years now and as he told us a long time ago...."IF" its running good and has oil pressure when you are "rolling" down the road, run it till you either "have" to pull it OR until you can afford to pull it and rebuild it!!" SO following others comments and or suggestions here!!!

Look up a couple posts I did a few years ago that describe how to
build a little test fixture and using a 1/2 inch electric drill and a
mechanical gauge test the oil pump and relief valve to see where
it dumps. Some will slowly drop and not come back up until the
engine is increased. This way when you install the pump you know
it works. I wouldn't put any pump in without testing first. G.M.

[Automotive Stud]

While those numbers aren't very high, my '47 has similar numbers and has been that way for years. Startup I get close to 70# but after warmed up going down the road I might get 20lbs, it drops down to about 5 at a slow idle warmed up, that's with 15w40 oil. I've driven the car from NJ to MD three times, I wouldn't hesitate to drive it anywhere. That said, at some point I plan to go through this engine.

[rockfla]

Originally Posted by G.M.

Look up a couple posts I did a few years ago that describe how to
build a little test fixture and using a 1/2 inch electric drill and a
mechanical gauge test the oil pump and relief valve to see where
it dumps. Some will slowly drop and not come back up until the
engine is increased. This way when you install the pump you know
it works. I wouldn't put any pump in without testing first. G.M.

Would that be the one you did with the "plastic tube" and "100psi Gauge"???

[Lawrie]

GM, you are right about the oil temp, for a long time I hade one on the 33,it would get to over 100deg C on long uphill pulls , ran around 75-80C on the flat in summer here.
Lawrie

[philipswanson]

Hey, old Chevies of that era didn't even have any oil pressure. Strictly splash!

[petehoovie]

This, from Ron Bishop's book "Rebuilding The Famous Ford Flathead" - Page 51 - "Ford used 40 non-detergent oil (Summer) in all of the flathead motors. The flathead oil system ran between 10-15 pounds of pressure, but is not considered a pressurized system by today's standards."

[tubman]

Originally Posted by petehoovie

This, from Ron Bishop's book "Rebuilding The Famous Ford Flathead" - Page 51 - "Ford used 40 non-detergent oil (Summer) in all of the flathead motors. The flathead oil system ran between 10-15 pounds of pressure, but is not considered a pressurized system by today's standards."

I find this to be an amazing statement and quite hard to take seriously. I think I have Bishop's book (I bought every flathead book I could ever find) and have not looked at it in years. I guess this helps explain why.

My rebuilt 258" engine with a stock Ford pump runs 55 psi at anything over 2000 RPM. My 1967 L79 Corvette 327 runs at it's factory specification as well. That specification is 45 psi.

[fortyonerag]

Originally Posted by philipswanson

Hey, old Chevies of that era didn't even have any oil pressure. Strictly splash!

The ol' 'Lucky Dip'.

[flathead4rd]

I run a 286 CI 8-BA with 20-50 oil. Runs about 50 psi at start up but when hot about 10 psi at idle. Have not had any problems in 10 years or more. I've been told that it isn't about oil pressure with a flathead it's about flow. Just my experience and I run it hard.

[Aarongriffey]

Old chevies of that area had 14 lbs. to the mains and to get oil up to the rockers.
The rods had dippers that were dipping into puddles that were full and running over with oil.
My dad had an old Oliver 70 farm tractor with a Continental 6 cylinder ohv engine.
The shop manual said, “remove the little oil galley plug and with the engine running the oil should barley trickle out. We worked hell out of that tractor and it never did quit and never showed any oil pressure. But those are different engines. Our V8s need at least 20 lbs. at speed
I’d drop the pan and check or replace the inserts. I’d also install an 80 lb. oil pump.
These engines are getting scarce.
Aaron Griffey
Hayward, CA

[Tinker]

anything above 0 to quote Bruce Lancaster. 50 hot is interesting. 5-10 hot is not out of normal and good.


Flatheads are not a high pressure oiling system. model A four bangers where just a oil delivery system.


If it's stockish... All that high pressure does nothing. Well it washes bearings. Relax it's all good.

[flatheadmurre]

Pressure and flow is what you need to get sorted out...as long as you have flow you usually get away with it.
With the exact same reading on a pressure gauge you can have very different scenarios...
You can have a good oilpump that is able to put out flow with a worn engine...it will run until the knocking and rattling scares the heck out of you no issues.
But the other way around a poor oilpump in fair engine will end up bad fast...
So just saying as long as you have a little pressure all is fine is a course diagnose.

[Tinker]

A gauge is a gauge it reads whatever. If you have a worn engine and a bad oil pump, well no flow or pressure.... If you have pressure you have some flow. Bearings help to create pressure... if the pump is bad as well... 0 is bad. But without pressure you have no flow.



Saying flatheads need more oil pressure then "we think they do". High pressure oil pumps are neat but not necessary. Hot oil pressure at a reading of 5-10 lbs is not a rebuild or bad motor scenario. It's just stock normal hot oil pressure.

[alanwoodieman]

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well we changed out the relief spring under the intake to NOS and also added a 1/4 washer this helped with the initial oil pressure but about the same running down the road, think we need to rebuild another engine--not sure a new op would help but at the cost of a gasket we might try. I do have a few used pumps ,including some 80 lb pumps, if I did this should we block off the reief spring under the intake or what?

[Mart]

What you just said makes sense. The 80 or 50 lb is a maximum. When warm, running down the road or at idle you are nowhere near the blow off pressure of the valve, so beefing it up makes no difference.

Personally I'd leave both valves in place so the oil feed to the timing chain area is regulated properly. But that's just me and I've never had to do it.

[flatheadmurre]

If it has the original pump putting in a 80 lb pump raises the flow so it will be able to maintain pressure better when hot.
The relief valve in the gallery should be left in place it serves dual purposes.

[G.M.]

Originally Posted by alanwoodieman

well we changed out the relief spring under the intake to NOS and also added a 1/4 washer this helped with the initial oil pressure but about the same running down the road, think we need to rebuild another engine--not sure a new op would help but at the cost of a gasket we might try. I do have a few used pumps ,including some 80 lb pumps, if I did this should we block off the reief spring under the intake or what?

I usually use a piece of 1/4" pipe 3/8" thick for a spacer. If it also
has a valve in the pump the valve with the weakest spring will
determine the pressure. G.M.

[alanwoodieman]

GM how did that 3/8" spacer affect the oil pressure?

[Kurt in NJ]

If you really want to know where your oil pressure goes use a pressure pot of oil to pressurize the oil gallerys before you put the pan on, then look where the leaks are, the bearings should drip, any missing plugs will make a big leak, and a steady stream out a bearing probably means too much clearance or a defect

I had to fix a Mercedes engine that the owner said had no oil pressure showing on the dash,that the gauge must be bad, it had 3 lbs at 2000 rpm on external gauge, it had been driven a month that way, I found 1/2 a bolt on top of the oil filter, upon removal of the pan 1/2 of the oil pump housing laying in the bottom,a windage tray bolt had been sucked in, no bearing damage, just a new oil pump

[Tinker]

So 80 to 50lb is normal, hot or cold...... hmmm

[V8COOPMAN]

Originally Posted by Tinker

So 80 to 50lb is normal, hot or cold...... hmmm

NO...…...80 or 50 lbs. MAXIMUM is normal, hot or cold. ALL words matter! DD

[Jack Shaft]

Is the hydrodynamic principle fulfilled?once that occurs oil pressure doesn't matter..model a engines relied on 3 inches of gravity to satisfy the bearing demand.



.001 bearing clearance per inch of journal diameter,,10 inch diameter battleship crankshaft? .010 bearing clearance..any oil pressure beyond whats needed cools and cleans the bearing,but isn't necessary for function

[Tinker]

Originally Posted by V8COOPMAN

NO...…...80 or 50 lbs. MAXIMUM is normal, hot or cold. ALL words matter! DD

It's a unicorn. Most flatheads are low pressure oil. It's not right to say a motor at 10lbs hot is a goner. I have a tight rebuilt that runs 50 at start and hot idle at 20. It's a good rebuild and no I didn't put a high pressure oil pump in it.

[tubman]

Originally Posted by Tinker

It's a unicorn. Most flatheads are low pressure oil. It's not right to say a motor at 10lbs hot is a goner. I have a tight rebuilt that runs 50 at start and hot idle at 20. It's a good rebuild and no I didn't put a high pressure oil pump in it.

Are you kidding me? Factory specs say 55 lbs at 2000 RPM and 25 psi at hot idle. My engines meet these specifications. I can't help it if you have a bunch of worn out boilers.

I thought one of the the purposes of this forum was to promote quality builds. I hope I'm not wrong.

[Tinker]

Tub you first to get at me. In a perfect world you will be the first to put another motor in it. Sure you can tell me how to convert to 12 volt too.

Flatheads will always be a low pressure system. 10-20 at hot idle is normal.

[Tinker]

Originally Posted by tubman

I thought one of the the purposes of this forum was to promote quality builds. I hope I'm not wrong.

You are right. Share your rebuild. I've shared a couple rebuilds here and on the yblock forum. Have at it.

[tubman]

Originally Posted by Tinker

You are right. Share your rebuild. I've shared a couple rebuilds here and on the yblock forum. Have at it.

It was done by a guy named "Dave" who runs the machine shop at the NAPA in Baxter. He told me that he had never done a flathead, but had worked for a Ford implement dealer and had done a bunch of 8N's and 9N's. That was all I needed to hear. Everything went great (and it didn't break the bank, either).

[Tinker]

Ya stop telling me how it is, show me.

[V8COOPMAN]

Ya can't fix a flathead that ain't broke.....…..well, ya just can't! DD

[Tinker]

I think you are the next guy to tell me something. Like 3sp transmissions are stupid. If I cared about running like a modern car I would buy a camry.

[flatheadmurre]

Hey hey guys...remember we´re all here to enjoy and share...
And i thought i was the argumentative guy around here...i have to sharpen my skills

[Jack Shaft]

Electric oil pressure gauges are suspect.Mechanical gauges are closest to accurate at the center of the gauge needle sweep.The reason the factories went to idiot lights is thats all the operator needs,excess oil pressure in actuality robs power by loading the pump..idiot lights stopped idiots from wrongly assuming engine wear from a 5 dollar gauge.

[petehoovie]

From 'Roadrunner Engineering' > http://www.roadrunnerengineering.com/TechTips.html

"As many flathead owners have observed, the idling oil pressure for a warm flathead is often 10 psi or less. While 10 psi is sufficient at idle (it should rise approximately 10 psi per 1000 rpm) it is not very comforting to those used to the higher numbers from modern engines."


"Melling Engine Parts manufactures a high volume oil pump for the flathead designated the M-15 which delivers 25% greater volume capacity than their model M-19 which is the stock equivalent. Peak oil pressure is set by the oil pressure bypass valve (either in the pump or in the engine), however the higher capacity will produce significantly higher oil pressure at low engine speeds. To use the high capacity oil pump in 1948 and earlier engines, a truck oil pickup tube assembly, P/N 8RT-6615 is required. The 1949 and up engines can use their stock oil pickup assemblies. Some bending of the pick up tube may be required to assure adequate clearance (about 1/2in) between the oil pickup screen and the oil pan. The oil pressure relief valve in the center valley of the older engines is usually left in place even though the new pumps have a built in relief valve."

[40 Deluxe]

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This may be apples to oranges (at least it's Ford to Ford), but I drag race a Cougar with a 289. I shift about 74-7500 RPM and cross the line about 6500. I run a stock oil pump and stock relief spring. So around 45# max hot. When I built the engine in 1990 the crankshaft was standard and in good shape. I had it apart about 4 years ago to put in dome pistons and the crank was still in good shape and still standard. This is after many hundreds of runs. The main and rod bearings looked and miked perfect so back in they went. So why waste engine power churning oil through the relief valve with a high volume, high pressure pump??! If you like to overheat your oil why not just heat the pan with a torch? I was running 5W-40 oil until I couldn't find it anymore. Now running 10W-30. "80 lb. oil pump"? Egads! No way! There is no need for worry if a typical flathead idles at 10 PSI and cruises at 35-40 PSI.

[alanwoodieman]

40 deluxe you need to go back and reread oil pressure we have now. 12/15# at 55mph about half what it should be, idle 2/3 # as the song says "those statistic for a modern engine, don't impress me much"

[40 Deluxe]

Originally Posted by alanwoodieman

40 deluxe you need to go back and reread oil pressure we have now. 12/15# at 55mph about half what it should be, idle 2/3 # as the song says "those statistic for a modern engine, don't impress me much"

Point taken. I was responding to comments that seemed to recommend a need for extreme oil pressure, like 80 lbs., which is totally unnecessary.

[Ol' Ron]

This might not answer the question. but, I had an old engine that didn't have any oil pressre at Idle. I pulled it from the truck and set it aside. A few month/years later I installed it on a run stand and it still didn't have any pressure at idle. I removed the plug from the pump outlet on the block to see if it was putting any oil out, When I started the engine the oil shot out across the yard,. Not sure what happened to that engine, we were going thru allot of them back then

[Ronnieroadster]

Well this post is up to #50 now so after that many posts the winner I mean answer is?

[alanwoodieman]

40 deluxe, what we are think about is the high volume pump which happens to be the 80# variety, actually what we are looking for is more oil flow not necessarily a lot more pressure

[cadillac512]

Originally Posted by Ronnieroadster

Well this post is up to #50 now so after that many posts the winner I mean answer is?

In my opinion, you and murre had the correct answers and procedures in posts #10 and #11.



Terry

[Ronnieroadster]

Originally Posted by alanwoodieman

40 deluxe, what we are think about is the high volume pump which happens to be the 80# variety, actually what we are looking for is more oil flow not necessarily a lot more pressure

Heres some food for thought using the 80# pump will not give you more flow. If more flow is what your after than the Melling M-15 HIGH volume oil pump is the one to use. Now I know theres going to be a flood of comments that the M-15 pump should not be used however. The decision to try a pump for more flow will only be accomplished by installing the M-15. And to add to more comments heres what you should do with your front pressure relief spring area. Place a small ball bearing in the chamber doing this will close off that front oil leak complexly. Use the plunger {the stem will need to be shortened slightly so the cover can go on} and spring to hold the bearing in place. You should see a slight improvement in your pressure reading. And the answer is yes to the question have I tried this myself and I can say no flatheads were harmed in any way during those experiments. As a matter of fact they all have survived rather well.
Ronnieroadster

[petehoovie]

Good info in these PDF's from Melling >

https://www.melling.com/wp-content/u...re-vs-flow.pdf

https://www.melling.com/wp-content/u...lume-pumps.pdf

[flatheadmurre]

If the engine has the original longbody pump in it now changing to a shortbody #80 std pump actually raises the flow a bit since you are going from straight to helical cut gears.
If a fresh shortbody pump aint enough i would check the bearings and surfaces next.
If we start blocking the gallery oil relief spring the oilpressure gauge will probably peg for a long period...and it shouldn´t open until #50 is reached if in good shape.
There´s no simple answer to theese kind of problems...taking the pan off and checking bearings would be the best start.

[Tinker]

Originally Posted by flatheadmurre

Hey hey guys...remember we´re all here to enjoy and share...
And i thought i was the argumentative guy around here...i have to sharpen my skills

I'm not offended. or care. It's just banter to a solution. Totally not offended personally.

[Tinker]

Bearings limit flow. Better bearings better pressure. If you need to add more oil pressure I'd last to think the pump. But too much pressure is just that, same with flow. In my opinion on a flathead. 90% of us don't need 90 lbs of oil pressure. A few might. 10lbs is all you need hot idle. If you think you need more oil pressure on a flathead, add more fuel pressure to your carburetor to make it faster.

[Brian]

Ok, so you've got an 80lb pump installed with a built in relief valve. Others have said you can 'regulate' the engine oil pressure through the relief valve at front of valve chamber. The engine will see pressure as regulated by the lower setting of the two r/v's Way I see it, the rear main which is fed directly from the pump can conceivably get higher pressure than the rest of the engine. Which adds to the rear main leak in engines not equipped with a rear seal. Or am I wrong?
You all know I play with 21 studders, always chasing that rear main leak...just because I run a 336 oil pump in it!! [Hi flow or what?!!]

[Tinker]

If you are going to regulate it with spring pressure, why do you need a high pressure pump? Just asking.

[flatheadmurre]

Originally Posted by Brian

Ok, so you've got an 80lb pump installed with a built in relief valve. Others have said you can 'regulate' the engine oil pressure through the relief valve at front of valve chamber. The engine will see pressure as regulated by the lower setting of the two r/v's Way I see it, the rear main which is fed directly from the pump can conceivably get higher pressure than the rest of the engine. Which adds to the rear main leak in engines not equipped with a rear seal. Or am I wrong?
You all know I play with 21 studders, always chasing that rear main leak...just because I run a 336 oil pump in it!! [Hi flow or what?!!]

The pressure isn´t going to be higher then the lowest relief spring dictates...only one pump so only one pressure within the engine.
That said oil lines restricting flow can make a difference....but not splitting into 2 oil lines with the relief spring in the end of one line.
The added flow is the issue for the slingers to handle...can only throw out and gravity feed back so much oil...

[Jack Shaft]

As long as the bearing requirement is satisfied additional oil pressure is nothing but a load on your engine.Insert bearings require additional pressure than whats needed to satisfy the hydrodynamic principle,this few pounds of added flow and pressure help keep the bearing cool and clean.Only a slight amount of flow/pressure is needed to accomplish this,your increasing the flow through a .0015 gap in a 2" bearing..Anything more looks good on the gauge,but isn't necessary.
Ford satisfied the bearing requirement on the model a engine with gravity,oil is pooled about 3 inches above the main bearing and flows down a tube to feed the mains. The model b engine with pressurized mains ran about 5 psi pressure,enough to do the job.
Companies that make high volume/pressure oil pumps are in business to make money,if the customer is comforted by high pressure then they will fill the need.

[40 Deluxe]

Originally Posted by alanwoodieman

40 deluxe, what we are think about is the high volume pump which happens to be the 80# variety, actually what we are looking for is more oil flow not necessarily a lot more pressure

Well, the extra flow from a high volume pump has to have somewhere to go (through loose, worn bearings) or else it just gets churned through the bypass (relief valve) wasting power and heating the oil. Since there is no need for 80# of oil pressure, just replace the relief valve spring with one that opens at a lower pressure.

[alanwoodieman]

we are looking for more flow-flow-flow using an high volume oil pump with the helical gears should do that and leaving the 50 # relief under the manifold should control our oil pressure. going to do this just to waste time and energy and a pan gasket plus get every one on this post the chance to add their two cents worth. we will see what gives probably next week. stay tuned for more fun on old ford flatheads!!

[Ol' Ron]

the bennafet racing gives to these engines is: A prolong period of time to observe the modifications you've made to your engine. This comes in two areas. One performance.Two reliability. To build an engine that has the power to run 200 mPh at bville and stay together for several runs. or a stock car engine that runs at least 50 laps every saturday night for several weeks, and beyond. oil pressure and cooling are the two things that make this possible, and we learn by our mistakes.

[alanwoodieman]

well better late than never--Monday/Tuesday we will know what an high volume 80# pump does for our problem

[F-ONE]

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The oil filter can rob some of the pressure if the wrong fittings are used.

[Brian]

So, how does oil being dumped by the relief valve get heated anymore than the oil flowing through the bearings, removing heat from the bearing as it does so? If the oil going through the bearing is removing heat from the bearing, it is doing so by absorbing that heat. Oil returning to the oilpan through the relief valve is doing exactly that; returning to the pan. So how is it getting heated? Surely it is at the same temperature upon leaving the pump as the remainder of the oil that circulates throughout the rest of the engine?

[Ol' Ron]

Brian The relief valve has a spring, which must be overcome to open, allowing oil to escape. When building hydraulic power supplies for the machintool industry OSHA required us to reduce the noise of the supply. We inclosed the supply and installed a cooling system. We installed sensors on all the components in the unit and the relief valve was one of the hottest.

[JSeery]

Originally Posted by Brian

So, how does oil being dumped by the relief valve get heated anymore than the oil flowing through the bearings, removing heat from the bearing as it does so? If the oil going through the bearing is removing heat from the bearing, it is doing so by absorbing that heat. Oil returning to the oilpan through the relief valve is doing exactly that; returning to the pan. So how is it getting heated? Surely it is at the same temperature upon leaving the pump as the remainder of the oil that circulates throughout the rest of the engine?

It takes energy to move the oil. The higher the pressure and flow rate, the more energy required to move it. I think the biggest issue is the energy losses. The energy loss can be in the form of heat. But the main activity going on is more resistance in the pump to move more oil. And a lot of that energy is being dumped out the relief valve.

[Mart]

All I know is that when as a kid I used to put my finger over the end of the bicycle pump, when I pumped it got hot really quick.

[alanwoodieman]

installed 80# high volume oil pump, 20w50 oil, started up at 60# at idle, warmed up the engine, drove about 20 miles, goes down the road at 30/35# ( compared to 7/10# before) at 50 mph, idles at 7/10# hot (compared to 0# before) guess we will see how long this last. told owner to save his pennies for a rebuild

[Karl]

Isn't flow just as important as pressure ? I had a friend who rebuilt his Austin ( Bantam) 7 He narrowed the oil feed pipe to the dipper wells . On the dash he had great oil pressure at the dipper wells he had less oil and he ran a bearing -Karl

[GB SISSON]

Originally Posted by fortyonerag

The ol' 'Lucky Dip'.

We always called the 216s a babbit beater. Of course it was 54 when gm went to a full pressure 'real' system.

[Tinker]

...

[russ40standard]

Originally Posted by alanwoodieman

installed 80# high volume oil pump, 20w50 oil, started up at 60# at idle, warmed up the engine, drove about 20 miles, goes down the road at 30/35# ( compared to 7/10# before) at 50 mph, idles at 7/10# hot (compared to 0# before) guess we will see how long this last. told owner to save his pennies for a rebuild

80# high output oil pump replacement by alanwoodieman was successful (I'm the owner). Added 1/2 quart of Lucas per recommendation, and the oil pressure is now good on this million mile engine. I have no history on the engine. A side benefit of replacing the oil pump is that a new rear seal has reduced the oil leakage when parked in the garage by 90%. Down to "normal" leakage now.

[Zeke3]

Welcome aboard. Glad to hear the update is working out for you.

[Mart]

Glad you have reached a solution.

[Tinker]

So lucas oil is thicker... higher oil pressure? You can run straight 30w to do that. Friction cases heat, the thicker the oil the higher the temp... but higher gauge pressure..... High Oil pressure is hype.

[Tinker]

OP Be happy....

[russ40standard]

I was running 20W50 Kendall before the oil pump replacement, with as much as 1.5 qts of Lucas mixed with the oil....Pressure was way low, under 8 lbs at speed, zero at idle. Also, I tried straight 40 weight before the oil pump replacement....No difference. After the pump replacement, I was getting pretty good readings on 20W50 Kendall before adding the Lucas. Picked up maybe 3-5 lbs extra oil pressure with the 1/2 qt Lucas. The new high volume pump was the solution to this issue. Lucas was icing on the cake. Thick icing for an old engine with an unknown history.

[Adam/Mill Valley CA]

Trying to resurrect this old thread, any update as to how this tired old motor has done after replacing the oil pump with a #80 high output pump a couple of years ago?


Adam

[Karl]

Originally Posted by philipswanson

Hey, old Chevies of that era didn't even have any oil pressure. Strictly splash!

Yep but the oil flowing into the dippers created 70lbs pressure in the rod bearings.

[Tinker]

Pretty sure it blew uo and he had to resort to getting a nova.