MMX Hemi Lifter Tech Video
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- Опубліковано 3 тра 2020
- Our engine builder and HEMI Tech, Byron, reviews some commonly used lifters.
Shop MDS delete kits: www.modernmusclextreme.com/CSe...
Shop Comp Cam 15820-16 link bar lifters: www.modernmusclextreme.com/p-1... - Авто та транспорт
Thanks Byron, this was very informative, keep giving us motorheads the info we need.
New subscriber! This was probably a hard video to make but I'm so glad u did because I got a lot of answers to questions I had. Again, great video. Keep it up
Thanks for giving your experience & knowledge
great video - thanks!
Great info. Thanks MMX
Please shoot another video with a better mic. From what I could understand, this was great info. Just wish I could have heard it all..
it sounds like you're under water and using a reverb pedal.
Better production. I didn’t need to see you pump your garden sprayer!
Should also should have mentioned metallurgy, lifter weights and design of roller needle bearings and axle diameter. .
Thats what I got from Summit racing and it caused me to spin a rod bearing and oil pressure was low, rebuilding now with Johnston Lifters!
Really good video
The comp lifters seem pretty sweet..
great video great infomation the comp lifters you used there can they be used in a 05 or newer 5.7 hemi.?..
Thanks for the video me and my daughter are rebuilding one right now have a great holiday👍
Lot of info!!! Will have to watch a few more times but for now 3 questions: how does the Comp Cam bar get lubricated? How/where are the lifter cubicles (lifter valley) oil drain back holes? And are the 2019+ hellcat redeye engines considered Gen 3? Thanks
Have you tested the comp 15821-16? That’s what I’m looking to buy very soon if I could get a response that would be awesome. Thank you guys for the great video. I knew those TSP lifters were junk
The problem with the "demo of competitors" is there is no springs returning the lifters to stop dumping oil pressure, and no oil pump maintaining pressure.
One of the main failures of the lifters is the rollers not being oiled well at idle. Once the roller bearings fail, so goes the camshaft.
Great video and demonstration of the flaws of the lifters. Thanks for posting this.
I would like to replace the 5.7 non-VVT MDS HEMI on my Durango with an MDS delete kit. I am not sure which parts to buy, and not able to get CS on MMX to respond to email or phone. Can you post the lifter part numbers or the weblink here? I would much appreciate it. Thanks.
So that was a static test. Question-Doesn’t that oil hit and wash over the cam (good) and pressure/flow refilled by the pump over and over when the engine is running? Pressure is good but so is flow. Also, does your lifter support cam lubrication as well? Just curious. Thanks.
do the last set of lifters have holes over top of the rollers? also what brand? us 3rd gen HEMI owners might need band aids for our cam/lifter problems.
Did you test the Comp Cams 856-16 & 15821-16 lifters?
When you delete the MDS solenoid the Lifters are feed from both, the Pushrods and the passage off the Heads feed.
Most cases the mds solenoid is left installed and just tuned out.
@@fuzzball94 Is there a tuner that turns off MDS? If so, please let me know and TIA.
I saw your reply to another person but I want to ask to be clear, if you could help me out i would aporeciate it, im having a mds 5.7 put in my 2013 GRand cherokee. I do not care about the mds. I care about lifespan. If i use the block off plugs and tune out mds am I doing the best thing? Its a jasper reman and they use the newer hellcat lifters. I cant afford a cam and stuff plus I want to keep the 3 year warranty. I can leave the solenoids in if thats just as good but I think you said plugs is making more oiling for the lifters. Thanks if you have time to reply, you seen very knowledgable.
Hi. I have 2012 6.4 manual so no Mds. Just had a lifter collapse and getting new cam and lifters. The shop recommended stock lifters but is there something better that is less prone to failure? Comp cams?
Please improve on audio and more close up engine and lifters demonstrations.
I know this vid is three years old, but in your opinion what lifters and cam brand should i buy to keep MDS and replace the stock cam and lifters. I`m not looking for any performance gains at all....just a good quality direct replacement
what are your thoughts on the new comp short travel lifters??????
So, are you compressing air?
I would like to see how the crower lifters do
What about Johnson lifters?
What lifters do you recommend for the comp cam?
so any oem non mds lifter will work like came in my 2004 truck
From perusing the internet, it seems that the roller bearing axle, surface and cam lobes are splash lubricated. I’ve seen that in multiple places from different people. Assuming that is correct, the first set of lifters, while poor quality, caused oil to drip down on the crankshaft. Not great for high RPM racing motors. But a lot of the lifter cam failures have supposedly been on engines with a lot of idle time. That leaking, in a more controlled fashion, would definitely cause more splash lubrication that might be beneficial in those cases. Engineered into a higher quality lifter. With MDS inactivated. Please let me know where that thinking is incorrect?
Always remember that oil pressure, while important, must be accompanied with high flow for proper lubrication and heat removal.
Don’t refer to them as “Hellcat” lifters, as I was told by a couple of idiots on a certain forum! Even though the lifters I was referring to were coming out of a 19 Hellcat engine that had an exploded supercharger.
Its the same lifter... the AD part number
Will the comp lifters work in my 06 6.1 hemi?
Has anything changed in the lifter world for the gen 3 hemi to date? This video is 3 years old.
Would like to see mic #’s
I bought those cheap lifters with hole in body and installed them in my truck. At idle the oil should be hitting the spinning crank and splashing oil onto the cam. If had bought the oem hellcat lifter it still doesn't fix the oiling issue with block. The cam still doesn't get oil properly at idle hence the premature failure of hemi lifters.
When the MDS solenoid is installed (and not activated) the Lifters are not getting any oil around the body of the lifter. When the MDS plug is installed it pressurizes the oil galley under the lifters and allows oil to flow around the body, and drip oil onto the roller/camshaft.
No the gen 3 hemi cam and crank are not open to eachother the cam gets absolutely no splash from the crank. It’s a part quality issue not oiling issues.
When deleting mds is necessary to replace the mds solenoids with the non mds plugs? Also, wouldn’t that throw an open circuit code if I leave them unplugged to nothing? Or does the diablo predator tuner remove all inputs/outputs related to the mds system?
they turn it off.
I went with Crower performance lifters when I deleted mds on my 5.7, good or bad ? I can tell you the hemi tick that I had with the factory lifters is completely gone !
Glad to see there's hope for mine. It just started ticking slightly at idle when its warmed up.
But wait? Are you saying all MDS lifters dont dump? The MDS non deactivating lifters are made to dump? and that dumping keeps the cam lubricated?
Nope the non mds lifters dont have the holes.... aftermarket guys are adding those(he called them cheap off shore made). But they added those extra lubrication holes.
dude get a mike please way too much good info on here!!
We have
Thanks
So would i be safe turning off MDS with my tuner and leaving it at that? Or will I need to replace the cam and/lifters with the hellcat lifters and the COMP lifters? Thanks.
Replacement is recomended
Are your pricings in American
When you do the mds delete with the hell cat lifters can you still use stock pushrods?
Lalo Grove yes
Thanks for your insight. However I just installed a set of Johnson 2356 lifters in my 5.7 and I have no oil pressure issue. So I’m not sure how to take your demonstration.
Any updates on this?
I put those same Johnson lifters in my hemi and they work great,iam not putting much stock in this demonstration with the bug spray jug pumper
I hope i didn't make a bad purchase on my non mds Johnson lifters,they were very expensive,you never mentioned Johnson so i hope all is good,they seem at the moment to work fine.
What type of engine brotha? 6.1,6.4? Also did you have to get a longer pushrod?
@@G6.1 no,it’s just the little 5.7 L all stock,Johnson lifters still working great
Great info thanks mmx. This might be a stupid question but out of curiosity, with this test taking place at stock lift numbers, at what amount of lift would the comp lifters experience the same issue as the other aftermarket pieces?
Greg Drimmie they will work for entire range of lobes available
Upon further review; The culprit will escape most if not all Old School hot rodders...The oil
galley that has historically supplied ample lubrication to the Lifters, FUNCTIONS differently
on MDS equipped Hemi's....
According to MDS system descriptions available on line, the
lifters associated with cylinders # 1, #4, #6, and#7 are deactivated by applying PRESSURE
to a pin, retracting it from a locking position joining the internal components from the external
lifter -roller shell....Meaning that when NOT in economy mode, the lifter galley is Not at line
pressure......Let that sink in.....In order for the pressure to rise fast enough ( less than 0.4 seconds), that galley must Not leak out....
Sooooooo, the minor oil flow past the lifter does Not appreciably lube the roller......
Any roller Lube must (as UT said) come from splash....
Splash is much less likely in the Gen III than prior designs.....
On Non MDS or MDS delete engines, the solenoid plugs are replaced with plugs that allow full line pressure to the lifters 100% of the time.....However, the oil flow past the lifter even though it may be higher than the low / no pressure is still inadequate to lube the roller .....
Hence I purpose that a Small slot (0.010" deep by 0.050" wide) be ground connecting
the Galley recess on the "Top" of the lifter to the Inside edge of the roller support arm....
DON"T do this if you want to continue with the MDS system, real bad things will happen...
Please comment if I have perceived the system incompletely, I'd rather have the thing
correct than avoid an Oh Sh** moment.....
Is there a descent oil galley with the stock mds cam and lifters?
yes a big one... ua-cam.com/video/PAuNSYqOQjk/v-deo.html
I have a 6.4 in a 2500 and having lifter issues having trouble getting stock ones what’s your thoughts on the enginetech lifters?
Stick with the OEM Hellcat Lifters
I just have a question can I take a 5.9 magnum engine out of a 1999 truck and put it in a 1996 truck with the same 5.9 magnum? I was told some connectors and sensors may be different? Need help please
completely different
So the lifter oil galley isn't drilled all the way through? Where's it fed from?
plunger is fed from the head through the pushrod. the sides of the lifter is fed from a separate oil gallery.
Your Fucken Awesome dude" Thank you for this demonstration and hard work
👍👍 Will definitely buy the cam & lifter kit from you guys. When my Hemi finally blows 💣
so, do you guys know if the TSP lifters are any different? and would a hellcat oil pump help to keep pressure up?
These are the lifters TSP uses. Yes a Hellcat pump will help with pressure, however masking a known problem is definitely not the right way to go about building and engine. We have personally had a couple catastrophic engine failures due to using axle oiling lifters and a stock 5.7 pump. It's only a matter of time before this becomes more of an issue. 👍
thanks for the information guys
Kinzie, Jason the owner is talking abiut his 2 personal engines that failed back to back using Johnson lifters. There is zero documented engine failures in hemi's from using texas speed lifters.
7k rpm on nitrous with tsp stage 4.
A book of time slips, zero bearing material in filters or oil. 15,000 miles on the cam and lifters. Is it isn't an issue now, it won't be.
Wish I would’ve found this comment a week ago....
So my question here is are the original style lifters found in the 06 through 10 6.1L better to use than the updated, which has the oiling hole in the oil groove of the lifter and a slightly larger roller, lifters found in the 11 through 19 6.4L? There are two reasons I’m asking. First, I’m a Chrysler service advisor who sees this failure multiple times per week and the lifter you were showing is what comes out of anything from 11 to 19 from the factory. Second, I am personally rebuilding my engine (6.1l based 392 from Arrington) because of my 3rd set of failed lifters, all of which have failed on the #5 cyl! I’m tired of this shit as it’s not a cheap repair and I’m praying to God the the spun cam bearing didn’t destroy the cam journal of the block! Anyway any info is appreciated!
bmf572 is best to eliminate it
Period
Eliminate what? The engine (😆) or just stick with the original style of lifter? I wish I could afford the comp cams lifter but due to eye surgery in 2 days and the amount I have to pay after my insurance ($5l) it’s just not possible at this time.
@@bmf572 Whos rebuilding your engine? No way it should happen that many times... thats absurd. I think he thought you meant MDS lifters. I compare lifters here, and I show the Enginetech "leaky lifters" If your rebuilding get the latest design... they are rock solid... 503 8787 AD... Which fits the 6.1 It is the "updated" part number for all 2008-2019 Hemi challengers(5.7, 6.2.6.1, 6.4) Hellcats, redeyes, scats... RT all cars. Search on the part number on a mopar parts seller. The 6.1 came with that wierd AF lifter, and was replaced by the AD lifter... ua-cam.com/video/u5MGGl_5tl0/v-deo.html&
What do you guys think about Melling 689-JBK-7521? IMHO Melling is a top notch factory with affordable prices
Have not tested
hi I thought the problem is the splash dont hit the cam at idle. So I think there should be a small hole in the bottom of the lifter to supply the roller so it can lube the needle bearings and cam all the time.or the bottom of the lifter should have some kind of noch so when it comes up to gally it get the oil from gally pressure and pushes it down on roller and out onto cam all
the time.
Where does the Roller of those lifters get their oil???....If there is NO oil flow down
the lifter body that runs through the roller and on to the Camshaft Face, there is Only
Splash oil flow which apparently is insufficient in to guarantee roller lubrication.....
Did you even watch the video?
So my question is if you don’t sell these “bad” lifters then how do I have no oil pressure after buying a set from you guys? I’ll be calling you guys tomorrow morning
Edit: I should note I have absolutely no noise coming from the engine it is a quiet as it has ever been. Even at 10psi. I did not glitter the engine and trash a bearing I had absolutely no metal in the engine on tear-down. The only things changed were the chopstix cam,non-mds lifters,P-rods, and new stock springs. Mds obviously deleted with plugs installed. Headers. And a HP tune. All the valve train came from MMX. I’m pretty pissed right now. 5,500 dollars into this and I did a second teardown to put in a melling HPSV oil pump to achieve the exact same pressures. Unbelievable they can sell you shit that doesn’t work right. I’m no stranger to how an engine works and how to install everything on one. This isn’t making any sense to me unless you sent me faulty parts like you said you don’t do. We will see how much you stand behind your business.
My guy, if you need an audio engineer to clean up the audio before releasing these highly
Information packed videos about my particular engine, im willing to do the work for free my guy. I’d love to see the channel grow more. Thank you for putting out great content
As a audio engineer I agree. It hurt to listen to.
First thing I thought as well.
I would like to see a real running engine demonstration.
Being new to the "new" Hemis, im learning and researching before building my first one. Ive read much about lifter failure and destroyed cams. One opinion ive heard is that its due to lifter roller bearing failure because of insufficient lubing. Is that accurate?? And if so, then I see the point behind the cheap overseas lifter since it dumps oil onto the roller. Obviously its a bit extreme, and dumps lots of oil/pressure, but with maybe just one smaller hole it would be useful??? You mentioned "axle oiling lifters" also... Do any exist for the Hemis?? Just trying to get to the bottom of cam/lifter failure before I build this thing....
That’s what I was wondering, some oil leakage would be desirable to lube the needle bearings.
My ram does not make the famous ticking sound any advice if it does start
Start repairs immediately
@@ModernMuscleXtreme what lifters do I buy the hellcat ones
How is it a “hellcat lifter” when the part numbers are the same
All current lifters are superseded to the hellcat lifter
Would these lifters fit a 5.7 hemi
yes they are all the same
Dude, it’s gallery, not galley. A galley is the kitchen on a ship or boat that has a place to prepare food. Just saying
CAN"T HEAR YOU ! this is good info but ....
What is wrong with your audio?
It sounds like your talking from inside a hollow log.
if the lifters are getting oil from the rockers threw the push rods .... whats the gallery you are pressurizing for ... sounds back ward to me
its to lubricate the needle bearing and cam lobes... the dripping out the bottom does that.(he shows it slowly dripping out the bottom). ua-cam.com/video/ckIl1vuiXC8/v-deo.html
So it's best to use the hellcat lifters
Whoa Weezy in 99% of applications, Yes
I like the comp cam results better. The fourth one.
Hellcat lifters have been in all hemis cars since like 16-17 part number ends in AD
THE AUDIO IS VERY BAD
other than crower. who else makes a shaft oiled lifter?
Johnson possibly
Not sire on Crower but some aftermarket leak oil at max lift
@@ModernMuscleXtreme
I called crower. Their edm shaft oil lifters come from Michigan and are backordered indefinitely due to rona. Looks like i’m going to get the shrouded comp cam lifters and have a machine shop drill a 0.03 hole in them to connect the oil gallery to the top of the roller pocket.
Okay those "cheap" lifters are MADE to dump more oil on the cam, The only way to tell is build and engine and see if there is an "oil pressure" drop. I bet the oil pump can keep up... The cam spins btw :) so yes more oil is splashing on the cam. They call this an enhancement not a build quality issue. I would be very worried about the top of the lifter not getting enough oil... I don't see it having a long life at all.
What about johnson st2326 ??
another snake oil lifter... The new Mopar AD part number is going out in all hemis and they are good.
Hi, wich lifters do you recomend for a Hemi 5.7 345 non MDS. Pickup 2014 Stock mopar camshaft?
OEM Hellcat Lifters
Wtf I just put these in mine. I did not realize lifters were such a fuck show. My truck has always idled at 20 and still is but it’s Time to trade in the truck
I'm looking for some information about comp cams 856y-16 lifters that are advertised as being even better than the hellcat 700 HP oem lifters, I've not seen any reviews on these can someone tell me if they use them and whats there opinion please and thank you
Better than Hellcat are a stretch
Good lifter not superior
Looking to change platforms, this video didn't address the elephant in the room and how I found it....
The wearing of cam lobes due to lack of oiling both in orientation to the cam centerline and direct pressure axle oiling.
On my normal platform I've been running morel dual pressure fed lifters a long time....ive observed them create a sheet of oil on the lobe itself and with various bleed off rates/oil viscosity, travel and spring rates; they done a tremendous job of protecting my BBCs at idle and carry power out on an otherwise terrible factory geometry layout that usually lays over at 6200ish rpm in hydraulic design.....
We compensate for the loss of oil pressure by simply using more bypass spring pressure in our HV/HP melling pumps...tall decks even have a secondary oil pressure port across the front so i was indeed able to confirm the difference in pressure drop for similar lifter to bore clearances using pressure fed lifters and that part of the assertion in this video is for sure real....but isn't that the point?
My local Dodge dealership of which I ordered a 1320 and canceled after it didn't come in for 5 months, now looking again at scat packs....has stacks of cams that have been eaten up in the back of their service area.....
This video shows us what each lifter does under this test, but completely skirts why they tried to modify the original design aka cam lobe failure especially with cars in the city idling....( for us is was more of a handling of higher spring pressure protecting the rollers and lobe materials) a second cam on the lobe to see where the excess oil was going would be beneficial...
As I am new and SEEKING knowledge on this platform, I cannot assert the test was wrong however its my opinion why, even the comp lifter that was endorsed, are lifter redesigns attempting to add more oil to both the bore, axle wheel and cam lobe in the absence of proper cam windage....the fact the hemi non mds lifter doesn't leak any oil pressure would certainly indicate that its machined well and tight in the bore but is precisely what I'm reading ( as a newbie to gen 3 mopar ) is the cause of premature lobe fair aka lack of oiling at the lifter bore, axle, and cam lobe....
Without further examination of the endorsed comp lifter design ( why are they all trying to add more oiling?), this video would actually be an endorsement FOR pressure fed oil lifters to eliminate cam lob failure....id rather have some windage eating hp at the crank, than my lifters eating lobes.....
Again as a newbie seeking to understand ( especially after my rude introduction to the gen 3 coyote and its mismatching of cast pistons that have no hope of matching the thermal expansion characteristics of the plasma bore they are now housed in 3 engines in 8k miles)....
I was simply looking at buying a 6.4l new or used and quickly doing a cam lifter swap, possibly drop ins ( been 20 years since I didn't have boost ), precisely because I see video after video and post after post along with a stack of ate up cams at my dealer and ASSUMED they solved that issue like we did sure enough it landed me here....i also tried super expensive dissimilar metal bushing lifters as well. At least when they failed they didn't dump needles in the pan hehe......
Since text communication can come off wrong, I am not combative or mopar bashing I'm actively looking to join the club....the eating of lobe issue seems to be real and was seeking a remedy before I jumped...I assume that's what lifters with additional oiling are trying to do....if MMX thinks this is the wrong approach do you offer warranty on your lifter/lobe combos? I see how they are different but what were the manufacturers trying to do and why is important as well and the 800lb gorilla in the room to an outsider.
Is there a year model that has this issue solved ive seen some indication post 2016 ( same for hellcat blower )....looking to join the club ( like I was when I ran out of patience on my 1320), just don't want to jump in like I did with ford on a new engine generation and take it in the rear...lol.this boosted a10 mustang is nuts fast but my big ass prefers the styling and room of a Challenger...also miss the sound of a cam ;)
Thanks
BlueCollarDaily nice post
Not today but soon would love to chat
Dave Weber 276-340-3941
Text me your info so I can add to contacts or you could end up filtered
@@ModernMuscleXtreme I agree with BlueCollarDaily. The question that needs to be answered is why are the new designs adding oil supply to the lifter bores? Is this the cure for the lifter failure/cam damage the occurs due to a design flaw? See Uncle Tonys Garage video on that subject. You didn't show a close up of the "Hellcat" lifter (no such thing) . Does it have an oiling port too? If adding oil to the lifter bore is the solution then what is the optimum location of the oil port in the lifter so that oil pressure loss is mitigated?
@@alandingman4046 Uncle tony was drunk.. he didnt even know those oil galleys existed... Hellcat lifters are the latest lifters(AD) all hemis get them now. The failures are real though, I think its more and more quality control on lifters since they simply swap a new cam and lifters in the car.. Higher lift requires perfect lifters... A competent builder using AD lifters, removed MDS, you should be rock solid...No oiling port needed, Chrysler would have added it if they needed it. ua-cam.com/video/PAuNSYqOQjk/v-deo.html
Im right with you on this... If its lack of lube to the rollers that cause cam destruction, itd seem that the overseas lifters would actually be a potential fix. Admittedly the large amount of oil pressure loss and harmonics is an issue and problematic too... Just want to know what we can do to avoid eating a cam...!!!
Horribly distorted audio - fix the audio - make it over again, and pressurize an oil tank with a regulated compressed air line!
Hey man have u guys devoloped a bolt on kit for the hellcat supercharger to go on an 07 jeep srt with the 6.1l?? Ive been looking around and haven't seen much.
Francisco Gastelum there’s kit in mmx and there’s someone in UA-cam try the kit and hellcat supercharger on vvt 5.7
TSP sold me a “OE style lifter” and sent me this FN trash.
Yup
@@ModernMuscleXtreme no worries. You guys will be sending appropriate lifter to me. You should read these email battles they are having with me. Trying everything they can to not refund me. I guess it’s what I get for thinking a Chevy company can have any knowledge else where. I wonder how many people have bought from them and shoved these into their engines. Sad
More oil is better. Complete fail.
Dodge/fiat = phucking GARBAGE. Blame it on the quality of lifters all you want! STILL GARBAGE....
Did you go spray your lawn with that too? Very "professional" setup.
That isnt a claim to fame. Federal Mogul makes those lifters also. Dramatizing what is going on is very low quality jabs.
And "your competitors" use the Made in USA version. They are knocked off by the aftermarket, but you know that.
You're spreading fake news to boost your failing sales.
Since when did MMX lose credibility and integrity.
gectek dramatizing? They are showing why the majority of lifters are not benefiting anything. If you have zero comprehension on valve train dynamics and harmonics, you should keep your comments to yourself. Even if this happens at such a fast rate, you are still producing a leak that is not necessary. Also having ANY oil leak into the crankcase and getting whipped by your crankshaft isn’t good either. And having a litter that is fighting back the oiling process isn’t good either.
@@samuellaforest3048 harmonics? All they talk about is oil pressure loss. You sure dont know me bud or what I know. But I know all I need to about you when you just ASSUME.
They are overdramatizing by leaving BOTH lifters open at whatever lift they say. That never happens in real life. Its physically impossible. They even admitted on fb their test was overly dramatic. But also do you know how long that lifter is in that position. At idle, another guy posted .02 seconds. You can't even comprehend OR react that fast physically to show how much pressure is "actually" lost
They also described the wrong way for lifter oiling vs what they are showing. Which is what all professionals do right?
Where are your facts? Because i brought all mine to the table.
And how do you know where that oil is going anyway? It does actually oil the roller and axle. They cant show that because they want to pump their failing numbers up. So they show what they want. Again, integrity in question.
@@gectek just a question here. You said the lifters are never in that position, physically impossible. How about when the engine is turned off? Could lifters be left high enough exposing the oiling hole that the pressure bleed off happens making for a noisy start and low pressure situation in at least one lifter / bore?
tia
yeah this "omg" oil pressure is gone stuff, is splashing on the cam is EXACTLY by design... The non activating MDS lifters HAVE that same hole... All this does is peg the pressure relief valve in the oil pump... That lifer is moving rapidly and oil is seeping out at the bottom onto the lifter and cam... The one guy said he has the holes and his oil pressure never waivers...
@@brett9736 no engine will hold oil pressure after it is shut off, as the oil has many places to go (main/cam bearings, piston squirters, etc). an engine maintaining oil pressure after being turned off would require a total absence of oil flow in order to maintain pressure, and I'm sure the implications of that to a running engine are slightly more than obvious.
also keep in mind that pressure is not a measure of flow but rather a measure of restriction.
there are the newer engines with the start/stop system that kills the engine rather than idling when you are in stop&go traffic, they have lifters which are designed to not bleed down, which enables the very quick restarting of the motor when the driver takes their foot off the brake to begin moving again.
i read up on the design once but it was a while ago so I remember exactly nothing about it. I'm not sure if the stop/start system is a feature on any pushrod engines though, or if it is just on overhead cam engines.