Lifter & oil supply questions for anyone with *first hand* experience

[wes8398]

Happy New Year to anyone reading. I have some questions that the Google machine doesn't seem to be able to answer to my satisfaction, so I thought I would ask here. I'd prefer this doesn't turn into another arguement about what causes the lifter-eating-cam situations, but I guess we'll see how that goes. Anyway, my questions:

1) Does oil that's fed through the pushrods and into the lifter bodies make its way *through* the lifter and onto the rollers, or does it hit a dead end at the bottom of the lifter?

2) How much pressure is behind the oil in the galleries which contain the lifter bores?

3) Would oil that leaks between the lifter body and lifter bore more likely "drip" or "spray" out of the bottom end of the bores?

4) Does anyone have a good cutaway or schematic of the valve train oil supply on these G3 Hemi engines? (there's surprisingly very little in google image results)

 

[Mister Luck]

Found information in this thread

” Hemi Valvetrain Oil Flow Path “

 

[wes8398]

Found information in this thread

” Hemi Valvetrain Oil Flow Path “

Thank you. I've been there, but I either missed information or my questions weren't answered re: oil getting through the lifter, pressure of oil getting past lifter body/bore interface, etc. Those pictures were an awesome depiction to see, though. In the original thread they are posted in (a charger or challenger forum, iirc), the poster said he had all kinds of engines that he was going to do cutaways on, etc just for fun... Couldn't locate a follow-up from him though.

 

[Mister Luck]

Blueprinting information is going to be difficult to come by
but if you measure the volume of the passages and the pump pressure you’ll get a static number that will vary depending on rpm and oil viscosity this will also vary by the (engine year) , pump used and whether the rest of the engine uses the same or different sized oil transfer flow rates.
If you compare different published statistics and the manufacturer’s recommend viscosity changes you might save yourself some time if you’re just trying to be rational in choosing an oil type or weight.

 

[wes8398]

Blueprinting information is going to be difficult to come by
but if you measure the volume of the passages and the pump pressure you’ll get a static number that will vary depending on rpm and oil viscosity this will also vary by the (engine year) , pump used and whether the rest of the engine uses the same or different sized oil transfer flow rates.
If you compare different published statistics and the manufacturer’s recommend viscosity changes you might save yourself some time if you’re just trying to be rational in choosing an oil type or weight.

I'm really just trying to appease my own curiosity regarding oil supply to the rollers and cam lobes. I can't seem to find whether the lifter allows oil *through* them, or it's a dead end at the bottom, nor whether oil drips or sprays out of the bottom of the lifter bores. A "working" cutaway engine like the ones you see at big auto shows would be awesome! LoL

 

[blackbetty14]

As far as I'm aware the lifter do not have a bleed/oil lube port on the bottom of the lifter above the roller. Any oil lubricating is from splash or leakage around the lifter bore. Ive never seen a bleed port to pressurize oil onto the roller. Ive seen oil squirters under pistons but not for lifters.

 

[Wild one]

There is no pressurized oil fed to the cam lobe or the bearings in the roller wheel,they live on crank splash lubrication.
If your pockets are deep,you can spring for the high dollar Johnson lifters that do have a bleed hole to lubricate the roller and cam lobe,if you go for them,you'd probably also want to upgrade to the higher volumn Hellcat or Melling oil pump,as they do bleed off pressure
Read this article,it has a good picture of the 6.4's piston squirters.
You're not the first guy to bring up the idea of using something similiar as the squirters to spray oil on the cam lobe

We Scored a $400 Junkyard 392ci Hemi From a Ram Truck—and It’s the Mother Lode!

Our 392 BGE Hemi build-up journey starts with buying a mysterious junkyard Ram Truck 392 Hemi core. We crack it open and find the mother lode!

www.motortrend.com

 

[wes8398]

As far as I'm aware the lifter do not have a bleed/oil lube port on the bottom of the lifter above the roller. Any oil lubricating is from splash or leakage around the lifter bore. Ive never seen a bleed port to pressurize oil onto the roller. Ive seen oil squirters under pistons but not for lifters.

I assume this is because the inside of the lifter needs pressure to do its hydraulic thing. Although there are holes on the sides of the lifter body which push pressurised oil out into the bore, if I'm not mistaken, right?

 

[blackbetty14]

I assume this is because the inside of the lifter needs pressure to do its hydraulic thing. Although there are holes on the sides of the lifter body which push pressurised oil out into the bore, if I'm not mistaken, right?

On the mds lifters there are hole and pins that when mds is engaged oil is pressurized in the lifter bore which forces those pins inward and allows a piston inside to collapse and thus deactivate that cylinder. On a normal lifter the hole pressurizes the lifter to remove slack and preload and the oil in the lifter bore is to lubricate the lifter so it moves up and down.

 

[wes8398]

There is no pressurized oil fed to the cam lobe or the bearings in the roller wheel,they live on crank splash lubrication.
If your pockets are deep,you can spring for the high dollar Johnson lifters that do have a bleed hole to lubricate the roller and cam lobe,if you go for them,you'd probably also want to upgrade to the higher volumn Hellcat or Melling oil pump,as they do bleed off pressure
Read this article,it has a good picture of the 6.4's piston squirters.
You're not the first guy to bring up the idea of using something similiar as the squirters to spray oil on the cam lobe

We Scored a $400 Junkyard 392ci Hemi From a Ram Truck—and It’s the Mother Lode!

Our 392 BGE Hemi build-up journey starts with buying a mysterious junkyard Ram Truck 392 Hemi core. We crack it open and find the mother lode!

www.motortrend.com

I'm well aware that this has been discussed ad nauseum for a decade (not century! LoL) or more. As I thought I made clear in my OP, I'm not trying to be the one to find the answer or start another debate on metallurgy vs oiling vs whatever other theory. I'm just asking these questions for my own purposes.
It seems too easy to just repeat the line that "there's no pressurized oil fed to the cam lobe", which is what everyone in this camp seems to do. I'm just looking for some kind of proof, I guess. Because the oil that reaches the inside of the lifter is pressurized (to some degree, I have to assume), and the oil fed to the galleries wherein lie the lifter bores is pressurized (or so they say)... So does that pressure lead to oil *spraying* from the bottom of the lifter bore and potentially meeting the cam/roller interface? Or is it unpressurized to the point that it only drips/seeps from the bore? I still haven't heard or seen unequivocal evidence that the bottom of the lifter is a "dead end", either. I believe it is, but I want to *know*, because I've seen depictions of 5.7 Hemi lifters that show oil paths which include going through the bottom; and both of those things cannot be true at the same time.

 

[Mister Luck]

I assume this is because the inside of the lifter needs pressure to do its hydraulic thing. Although there are holes on the sides of the lifter body which push pressurised oil out into the bore, if I'm not mistaken, right?

I found an old link I forgotten about for more detailed oiling information its a great armchair read
(If you haven’t already seen it )

You might want to see about an apprenticeship with chrysler or an affiliate to really satisfy your interest.

 

[wes8398]

I found an old link I forgotten about for more detailed oiling information its a great armchair read
(If you haven’t already seen it )

You might want to see about an apprenticeship with chrysler or an affiliate to really satisfy your interest.

If it paid the bills as well as my current career, I'd totally do this! LoL Seriously, though. I'd love wrenching (and learning) all day. I'm afraid I wouldn't do well with the time constraints, though... I'm just a tad detail-oriented (among other labels). Ha!

Thanks for the link... Look forward to the read!

 

[wes8398]

On the mds lifters there are hole and pins that when mds is engaged oil is pressurized in the lifter bore which forces those pins inward and allows a piston inside to collapse and thus deactivate that cylinder. On a normal lifter the hole pressurizes the lifter to remove slack and preload and the oil in the lifter bore is to lubricate the lifter so it moves up and down.

Right, and this is part of why I question whether the oil from the lifter bores actually does only "drip" out of the bottom of the bore - because there's enough pressure there to push those MDS pins in, I have to wonder if that is enough pressure to cause the oil to *spray* from the bottom of the bore and actually reach the cam lobes (to some degree).

 

[Wild one]

The oil past the lifter is more a drip then a spray,and the flat plain the lifter sits on,means the majority of the drips don't actually migrate onto the lobe face or the roller.The hemi still gets it lobe lubrication basically the same way every V8 engine has for the last 65+ years,by the oil flung off the crank aka crank splash.One of the reasons why you want to up the idle rpm from the lowly 550/570 range it idles at stock,to at least 725 or more,and another reason why you don't want to baby a hemi.Driving one like grandma is the worst thing you can do to the hemi.So your theory of jumping in your truck and babying it when it's cold,instead of letting it get a bit of heat in the oil probably isn't doing your engine as much good as you think,as the oil isn't flowing past the lifter bores or being flung off the crank as much as you think.Number 1 reason to run an oil pan heater in Canada,instead of a block heater,as it's not cold pistons that make it hard to turn over,it's cold oil that takes power to pump

 

[blackbetty14]

Agree with wild on the oil spray from the lifters. I would suspect a drip at most. If you had a spray you would be loosing a massive amount of pressure due to bleed off. Then you would have to think that every mating surface would also spray oil like crank, rod and cam bearings plus the tops of the lifters around the pushrod cups. On the old school SBC and fords you could prime the oil pump with a drill and you could see the oil leak out which is where my brain gets this data from. That oil leakage was not a lot at much heathlier oil pressures than the Hemi puts out (60-80psi) easily. The bores and clearances are tight so oil leakage is at a minimum.

 

[wes8398]

Agree with wild on the oil spray from the lifters. I would suspect a drip at most. If you had a spray you would be loosing a massive amount of pressure due to bleed off. Then you would have to think that every mating surface would also spray oil like crank, rod and cam bearings plus the tops of the lifters around the pushrod cups. On the old school SBC and fords you could prime the oil pump with a drill and you could see the oil leak out which is where my brain gets this data from. That oil leakage was not a lot at much heathlier oil pressures than the Hemi puts out (60-80psi) easily. The bores and clearances are tight so oil leakage is at a minimum.

This is helpful to my noggin; thank you. I have to ask, though... If the tolerance between lifter body and bore were *that* tight, then why do lifters seem to fit in place so easily? And do we *know* that the pushrod cups, etc don't spray all over the place due to the constant pressure behind the oil? Also, if the pressure were to bleed off at the bore/lifter, would that really matter given that this is pretty much the end of the oiling line anyway? And given that the pump is constantly making more pressure...?

It's frustrating to me that people seem to have had this figured out for years and years; yet there are still so many others that are absolutley convinced that it's something *other than* an oiling issue (metallurgy, hardening, etc). Particularly, one YouTuber fella that I judged as spot on early on in my "research" - "Uncle Tony" - gets absolutely roasted quite frequently simply because he's not a "Hemi expert", although his general knowledge and common sense drew him to the conclusion of insufficient oiling.

 

[Mister Luck]

Most the problems encountered with oiling systems are returns to the pan for redistribution.
Competitive engines reserves are tested to beyond extreme conditions redundancies are made and then more are still imagined 7qts is a lot of oil and most V8’s I grew up with only used 5.

Tolerances are refined to allow for interaction between dissimilar metals and materials that support longevity (dependability) and serviceability.

The refinement in manufacturing processes and testing is giving us a product that is only appreciated by those with experience an knowledge of engineering aspects and the history of what has been successful, even more what has been unsuccessful.

But if a pencil pusher (accountant) gets in the way (of a rendering, a recipe or formula)
that’s another story.

 

[Wild one]

This is helpful to my noggin; thank you. I have to ask, though... If the tolerance between lifter body and bore were *that* tight, then why do lifters seem to fit in place so easily? And do we *know* that the pushrod cups, etc don't spray all over the place due to the constant pressure behind the oil? Also, if the pressure were to bleed off at the bore/lifter, would that really matter given that this is pretty much the end of the oiling line anyway? And given that the pump is constantly making more pressure...?

It's frustrating to me that people seem to have had this figured out for years and years; yet there are still so many others that are absolutley convinced that it's something *other than* an oiling issue (metallurgy, hardening, etc). Particularly, one YouTuber fella that I judged as spot on early on in my "research" - "Uncle Tony" - gets absolutely roasted quite frequently simply because he's not a "Hemi expert", although his general knowledge and common sense drew him to the conclusion of insufficient oiling.

The engineers originally spec'd a billet cam for the re-designed block in 09,which means they had an idea there'd be oil issues with the raised cam tunnel and the extra oil passage for the VVT. Cam issues do manifest themselves when manufactures decide to go cheap on materials and hardening processes,just look at GM's fiasco's with cams in their 305's and 350's in the 70's and 80's when they went cheap on the cam cores.Billet cams are fairly common in the high end performance engines including the hemi,for the lowly daily driver those are out of the question,along with re-designing the block to put more oil onto the cam lobes,so for the most part they're stuck with a good oil strategy including shorter oil change intervals and a good quality moly based oil

 

[blackbetty14]

This is helpful to my noggin; thank you. I have to ask, though... If the tolerance between lifter body and bore were *that* tight, then why do lifters seem to fit in place so easily? And do we *know* that the pushrod cups, etc don't spray all over the place due to the constant pressure behind the oil? Also, if the pressure were to bleed off at the bore/lifter, would that really matter given that this is pretty much the end of the oiling line anyway? And given that the pump is constantly making more pressure...?

It's frustrating to me that people seem to have had this figured out for years and years; yet there are still so many others that are absolutley convinced that it's something *other than* an oiling issue (metallurgy, hardening, etc). Particularly, one YouTuber fella that I judged as spot on early on in my "research" - "Uncle Tony" - gets absolutely roasted quite frequently simply because he's not a "Hemi expert", although his general knowledge and common sense drew him to the conclusion of insufficient oiling.

My response would be, are you removing cold lifters from a cold engine and is that how your determining clearances? I doubt your tearing apart a hot motor and all the metals inside the motor are expanding at different rates (iron block and steel lifters). I have no idea what the clearances are on a hot motor but crank bearings are say 0.022" on a basic 2.200" crank rod bearing. Push a 5w20 or 5w30 oil through that thin of a clearance at say 28-60psi and do you think its going to "spray" out? I know there is some "loss" as that's why there are chamfers on rod/crank bearings and they are likely lubed from oil bleeding out but i don't think they are spraying out. The top of a lifter is not sealed and it bleed out through the cup then up the pushrod to the rocker which lubes the rocker tip and that slow stream of oil cools the valve springs (traditional v8 engine design). On a hemi that changes as you have rockers in the upright position. Now how do those receive oiling (see pic) so does that mean the pushrod is not flowing oil to the top as well? The oil pump is a fixed flow pump, at given RPM it pumps given GPH or GPM, that flow doesn't change really. You have things like pressure bypasses and cavitation but essentially the flow is the flow and its likely a linear curve. At 550rpm it pumps X and at 2500 is pumps X... it will be the same (except bearing and clearance wear) 5 years from now. The pump doesn't constantly make pressure it continues to flow more oil which once its meets a restriction it creates pressure. Oil pressure is just a measure of oil restriction. Since the restriction is constant and the oil pump continues to flow more as RPMS increase it increases pressure till the bypass in the pump opens and once that is overwhelmed you can't really reduce pressure unless you have a bypass afterward (some have them integrated into the oil pan). Also leaks affect pressure and drastically affects capacity of the system. A leak at the end of the system still affects the rest of the system before the leak. Another thing to consider is how much oil pressure/volume is required to "float" the crank, rods, lifters and keep oil flowing to everything else (up to the top of the engine). You don't want to affect the oiling system where It can not float what needs to float. Also where you measure oil pressure is important... is it at the pump or is it after the crank... before the cam? On a LS engine pressure gauge sensors are at the back of the engine which is basically before anything and it measures the system as a "whole" but clearly you can see where it isn't exactly accurate.




To get more specific on the lifters, the bore clearance is a range of .012-.030". I would assume similar materials similar clearances across diff platforms. Roller lifters can absorb more clearance due to the roller design and remember it still needs to "float" in the bore.

How And Why: Checking Lifter Bore Clearance With Erson Cams

It doesn't matter what kind of lifter you run the correct bore tolerance is critical to avoid issues. In this video from Erson Cams we learn how to check lifter bore tolerance.

www.dragzine.com

For arguements sake a drop in pressure wouldn't be an issue if you can provide enough flow/pressure to float what needs to be floated. Creating more leaks would reduce pressure and could require a higher flowing pump to provide enough flow. I don't think the lifter bore is the way to go tho its horizonatal to the cam basically. A squirter on top would make sense as you want to direct it onto the roller.

 

[Mister Luck]

Right, and this is part of why I question whether the oil from the lifter bores actually does only "drip" out of the bottom of the bore - because there's enough pressure there to push those MDS pins in, I have to wonder if that is enough pressure to cause the oil to *spray* from the bottom of the bore and actually reach the cam lobes (to some degree).

There are a few tried and failed methods of pressurize oiling that exists for example pintle holes with caged bearings were used instead of spring loaded directional oil squirters on blocks , but either after neglect and or “extreme service” they would clog with coked up residue.

In other rarer examples of a factory assembled engine that was equipped with a crankshaft that had been processed and installed without oil holes amazingly it lasted around 10,000 miles is a reminder of what is unusually possible.

Engine blocks with half their capacities filled (with concrete) to reduce the amount of fluid circulation in order to increase its volumetric effectiveness , I suppose you could use motorcycle and oil cooled and 2 strokes in this example because those also have proved to be successful through the philosophy of less is more.