I've never seen a GOOD engine with 10 psi at idle.
The engines I've built are between 30 and 45 psi at 900 rpm.
HV oil pump vs Stock oil pan
- Thread starter 512Stroker
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The engines I've built are between 30 and 45 psi at 900 rpm.
Dave_J
Well-Known Member
If the OP "512" has a fresh build and it was pushing well above 10 PSI before he yanked the Slider cam and put in this roller cam and lifters and now he has "15-18 psi at (850 RPM) idle while in gear. 10W-40 Dino oil", he is above that 10 PSI @ 1,000 RPM.
I do not know if he posted his pressure at 1,000 RPM, could be it is well above the 18 PSI at 850 RPM, but speculation here. ASSuMe.
Edited to remove the following words. OP is block oiling the rockers.
He is oiling the rockers thru the roller lifters and pushrods so, not much if any PRESSURE at the fulcrum of the rocker. Pushing more pressure to the rockers will not help, BUT more volume may.
You guys will argue about Buttermilk in the dinner rolls for tonight's dinner.
I do not know if he posted his pressure at 1,000 RPM, could be it is well above the 18 PSI at 850 RPM, but speculation here. ASSuMe.
Edited to remove the following words. OP is block oiling the rockers.
He is oiling the rockers thru the roller lifters and pushrods so, not much if any PRESSURE at the fulcrum of the rocker. Pushing more pressure to the rockers will not help, BUT more volume may.
You guys will argue about Buttermilk in the dinner rolls for tonight's dinner.
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Dale Davies
Well-Known Member
You have no clue. I have wrenched for 30 years on everything from MG Migets to 150 ton rock trucks and done lots of field service. Now 10# idle oil pressure is not optimal. A taxi that idles half the day waiting for fares and then putzing around town just fast enough for OD to engage will not produce long life. One advantage taxis have is they do not drive short distances, get shut off and allowed to cool down again in -35°F weather, like personal cars. Cold starts are tough on engines.
Next question, how many of those engines that you say had low oil pressure caused rocker shaft wear, also had a lot of miles on them. 90% chance most did. Many start with worn main and rod bearings which allows oil to leak out. Now oil to the cam bearings is reduced, allowing them to wear. At the same time the rockers are wearing on the shafts.
I have rebuilt a lot of engines and repaired a lot also, and have also seen all kinds of failures. I have also rebuilt automatic and powershift transmissions from TH200s to the 600HP capable Allison powershift that goes behind 750HP 12V92 mining equipment and also some big ZF gear boxes. I do have a clue.
Detroit Diesel had a problem with some of their Fuel Squeezer 8.2L V8 engines breaking the socket on top of the push rod. There would be a polished ring close to the top of the cup and part way up the adjuster ball. Some came off a different machining line with a slight difference in diameter. The bigger ball would eventually split the cup.
Freightshaker had a problem with the air system on new trucks yesrs ago when spinon air drier filter canisters came out. The compressor governors were not unloading the air check valves and pressure would go up to 250 PSI. The plastic line to the wet tank would get hot, swell like a ballon and rupture. On one in the middle of the night, the drier cartridge blew right through the fibreglass hood. Scared crap out of the driver on a long steep hill in the Roger's Pass on Hiway 1 in the Rocky Mountains near Golden, British Columbia. Try getting a heavy load rolling again on a steep hill. The problem was Freightshaker had plumbed the pressure sensing line from the governor into the wet tank, instead of the dry tank. This allowed moisture into the sensing line which froze up in the cold. Had a dilly arguement with the Freightshaker engineer sent up to see what the problem was. Funny thing was, when I plumbed it into the dry tank no more problems. On pre-delivery inspection after that we ran it to the dry tank and no more problems.
512Stroker
We are all here because we are not all there.
I am oiling the rocker shafts thru the head not thru the lifters/pushrods
Stock oiling for an 1969 LA 340
Edit:https://www.hughesengines.com/Index...&level2=Um9sbGVy&level3=U29saWQ=&partid=33868
Dave_J
Well-Known Member
512, can you tell us what the pressure is at 1,000 RPM HOT, just so we know?
Dale Davies
Well-Known Member
If the oil pump was inspected, end clearance and to the housing clearances are good and no big gouges, it is not likely the issue. Now the lifter style may be. If they pressure feed the rollers needles, that introduces another "leak". If they are splash lubed, that is not the problem. If you have the pressure fed roller needle style, a high volume standard pressure pump will help bring the idle pressure up.
This is like science, you have to analyse all the factors and consider changes made. I hate throwing parts at a problem that are not fixing the problem.
cudamark
Well-Known Member
I never did much wrenching on big equipment diesels, but, in the 40+ years of working on car/pickup gasoline engines, I NEVER had an engine with 10psi at idle that had all good internals. There was always something out of specs....be it oil pump, mains, rods, cam bearings, etc. This includes some freshly rebuilt engines where the crank grind didn't match the bearing size, and various assembly screwups.
Dale Davies
Well-Known Member
I would expect his idle to be about 850RPM as per factory, or close. So I would expect 20 to 25# at 1000RPM.
Dale Davies
Well-Known Member
I agree. Repaired a number of farm pickups with the Ford 400 and about 100k miles on them. Their oil system is the same as the Cleveland. Oil light would ficker at warm idle at stop signs, so 3 to 5 PSI. The owners would come in asking if I could put a new oil pump in for them. Drop the pan and check the pump and measure clearances. Other than a couple of minot marks, they looked good. Pull 2 an 4 main caps and push the upper shells out. Copper all around. Pull a couple of rod caps and push the upper shells out. Copper all around. Then I would look up at the timing chain and bar it back and forth to see the wear. Yup, needs a timing set also. Phone customer to let him know the situation with a price. New rod and main bearings with a double roller timing set and good to go for another 100k. A couple of guys complained that I had not replaced the oil pump. I did shim the relief spring a bit to help the bearings last. Those that complained, I suggested that they drive it for a week. If they were not happy I would charge them for a new pump and not charge to install it. Never had to do that. One the crank was worn a bit so I got .001" undersize bearings for it. The standard bearings went in the next one. All had 100k miles or a bit more.
10# at idle would be a minimum with worn bearings. A new build has a problem. 15 to 18# is OK though.
Those old Detroit 71 Series were like the Timex adverts, take a licking and just keep ticking.
512Stroker
We are all here because we are not all there.
You have hit the nail on the head.
The current pump was inspected but not closely measured, not scored.
The current set of Comp roller lifters (junk) are pressure fed to the roller and the replacements rollers will have pressure feed rollers. Hence my upgrading to a HV oil pump. My only concern was using the stock pan. Many on here confirmed that the stock pan for a street applcation will work just fine.
Dave_J
Well-Known Member
OK, back on track of stock pan and a HV pump.
I think I had the older late 1970's Melling HV hit the pan on my 360 build. A quick dimpling with a socket and it cleared. I made the mistake of putting the Direct Connection High Pressure spring in the Melling HV pump and had over 110+ PSI at 2500 RPM and the older STP oil filter was "EXPANDED" a little bit too. Gauge only went to 110 PSI. This setup may pump the pan dry. It would shoot a stream of oil 20+ feet out of the sender unit threads if the sender was not on the block. OPPS.
Had to drop the pan and pull the spring out. Then had like 60 PSI at 2500 RPM.
I think I had the older late 1970's Melling HV hit the pan on my 360 build. A quick dimpling with a socket and it cleared. I made the mistake of putting the Direct Connection High Pressure spring in the Melling HV pump and had over 110+ PSI at 2500 RPM and the older STP oil filter was "EXPANDED" a little bit too. Gauge only went to 110 PSI. This setup may pump the pan dry. It would shoot a stream of oil 20+ feet out of the sender unit threads if the sender was not on the block. OPPS.
Had to drop the pan and pull the spring out. Then had like 60 PSI at 2500 RPM.
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Dave_J
Well-Known Member
When I was priming that 360 I had a Millwaukee Hole Hawg set on high speed of 1200 RPM. Mind you, the cam and oil pump drive is spinning half speed of engine RPM so this was like if the engine was running at 2400 RPM. That stream of oil hit the roof of my tall garage and oil shot everywhere. Hole Hawgs do NOT slow down fast when you take your finger off the trigger.
Dale Davies
Well-Known Member
With the pressure fed needle bearing rollers, the HV pump and stock oil pan will be fine. By the way, what is your oil pressure now at 30MPH and at 60MPH?
lead69
hopeless car junkie
Been following this thread and I have to say not one thing you posted above has anything to do with a hot street/strip engine. All I know is EVERY engine builder I know including those on this board use a high volume pump in everything that is semi performance period. Argue that fact all you want.
Dale Davies
Well-Known Member
Your choice. If not required by the chosen components, all you do is pump more oil which wastes HP and heats the oil. Your results may differ, but I go by experience.
512Stroker
We are all here because we are not all there.
Cruz'n speed @ 65 mph is around 3000 rpm oil pressure is 50-55 psi
Never really drive at 30 mph so I cant commit.
Dale Davies
Well-Known Member
Good. I would say no worries as it is.
Hmmm, 3000 eh. I would think consider an OD transmission might be a good investment if you put a bunch of miles on. I can not see fuel costs going down. An OD trans would bring the revs down to the 2100 to 2200. Less wear and a little quieter. Just a thought.
lead69
hopeless car junkie
It's been proven many times that the hp thing is a myth, I also go by experience-my own as well as alot of guys much smarter than me. The argument seems to be if you can "get by" with something at the bare minimum it's good enough, that may work on a stock engine but when it comes to a performance engine it's a great way to find out the weaknesses.
Dale Davies
Well-Known Member
Well, discuss the "HP thing" with the factories. They have the money and facilities to test these things and more. This be their finding.
As to a HP engine, that depends on the extent of modifications. As the build gets more extreme, more ancillary parts need upgrading.
Rat Bastid
Dunamis Metron
This is as a kind as I can say this. I don’t care. Anything with 10 psi at idle is junk. It may say that’s ok in the FSM but it’s not good enough for anyone that can use their head. If a diesel has 400 psi idle I wouldn’t care either.
If you think 10 psi at idle is great that’s fine. You are wrong and all your words won’t make you correct. I’ve seen the damage first hand. Get over it.
Rat Bastid
Dunamis Metron
So you have tested this theory? You think rockers grabbing the shaft doesn’t eat horsepower? You think the cam getting driven into the cam bearings doesn’t eat horsepower? You haven’t tested anything. And you are wrong. Because it can happen, it does happen and it should never happen.
Rat Bastid
Dunamis Metron
So you agree with Uncle Tony, who on his video produced as much evidence as you have about how much horsepower it takes to run an oil pump. It doesn’t take what you think. This has been tested so many times it hurts. On virtually every brand of engine. On a well tuned, scienced out small block Chevy it’s worth about 5 hp at 7,000 rpm. And that was with needle bearing rocker arms. I can tell you that as I said above that you will kill way more than 5 hp with the rockers eating the shafts. And again, your 10 psi at idle will be ZERO at the shafts. Prove me wrong. Hook a gauge up to the end of the shaft and learn for yourself.
Dale Davies
Well-Known Member
Do you read and comprehend what you read. You seem stuck on the 10PSI business. IMHO that is a minimum for a high milage engine that is still running. If I had a new rebuild with 10# at idle, I would be concerned and start looking for why. Idle for short periods is one thing, but I would look more at the driving pressure. If that is good, the engine will continue running for quite a while. With that statement I refer to an older engine and as long as it is not using oil.
I know this is a different engine, but look at the problems the Gen 3 hemi's are having with the roller rockers because of the low oil pressure at idle. The fix is put the hellcat oil pump in to increase the pressure to lube the lifters. Some poor engineering there on Chryslers part. It seems pressure is your friend in any engine.
Dale Davies
Well-Known Member
I worked on and for Detroit Diesel for years. When I lived in Regina, Saskatchewan, I would frequently get sent to a coal mine outside Estevan in the south east corner of the province to work on the 12V71 haul truck engines or the Allison powershift transmissions. One time I got sent down and told I did not need the usual parts. When I got there I was asked to tune up a 2300CID Cummins V12 in an Easyminer. The radiator is about 12 feet by 12 feet. All hydraulic drive, 4 Cat D8 undercarriages with hydraulic motors. Under it is a large drum with carbide cutters to chew up the coal which then gets on a conveyor into the haul trucks. The shop manual was in their library. Now Cummins hiway truck engines were 855CID. They also made a larger inline 6 of 1150CID. Then they had a 1710 cube V12 which was more or less 2 855 engines in one block. They did the same to the 1150 to get the 2300 V12.
The next week I got sent down again to tune it up again. I asked if I had made an error the week before. No, you did goodbut we had 4 other guys out to tune it up and liked the way it ran best when you did it. 2 mechanics from Cummins and 2 independent mechanics. The week after that I had to go down to tune up a Detroit 12V71 which always invariably involved an inframe overhaul as they worked too hard coming out of the pit. The radiator was out of the Easyminer. A welder had caught it on fire which with coal dust, diesel fuel and hydraulic oil all soaked up burned like crazy. But the engine ran good when they got it all back together.
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