Avoiding the hemi tick?

[Wild one]

Aren't we playing with a delicate balance between oil being thin enough to get more coverage faster during startup versus sufficiently thick enough to improve surface adherence?

Do you believe that additives such as liquid moly or LubeGard maintain sufficient surface coating to negate the requirements to use a thinner blend for better oil dispersion during startup and that we're better off with the thicker 5W-30 to further enhance surface coating and reduce friction?

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They're both a 5W when cold,i ran lubegard in the wifes 6.4 when it was still getting dealer oil changes.I'd bring the car home,drop the mopar paper filter,and install a RP 20-820,then top off the oil with lubegard. Now that it's past the dealer changes,i've been running it on Redline 5W-30,and it really seems to like that combo,as it's noticably quieter on the 5W-30 Redline then it was on PUP 0W-40 with lubegard. I think if your not running HPL or Redline oil,the lubegard is definitely a benefit. If Redline or HPL are to pricey,i'd run 5W-30 PUP and lubegard as a stopgap oil combo

 

[Burla]

There is no such thing. Oil is reaching every part of the engine at the same speed regardless of viscosity, unless you go way out of bounds and hit the pressure relief in the system. Beyond that, increasing viscosity just gives a tiny bump in oil pressure.

Well, I dont know how you would explain the many guys running 5w30 redline in the cold and having cold piston slap, and then when they change that oil it goes away. Maybe you right in a warm area, but as you know the cold does crazy things to starting viscosities.

 

[ramffml]

Well, I dont know how you would explain the many guys running 5w30 redline in the cold and having cold piston slap, and then when they change that oil it goes away. Maybe you right in a warm area, but as you know the cold does crazy things to starting viscosities.

Piston slap doesn't go away (at least in my truck) for a good few minutes. If it's truly piston slap which is the piston slapping in the bore then it requires heat for the piston to expand and close the gap. It should just take a second or two for the engine to be completely pressurized with oil. Our hemis use positive displacement oil pumps, these pumps don't pump faster or slower or less or more depending on viscosity, they pump the same amount with the only change being the PSI at which it pumps. It's basically a lopsided gear sitting inside another gear and it forcibly squeezes the oil through the system, if you change the viscosity only the pressure changes but it's still squeezing the same amount through.

Piston slap was one of the main reasons I've tried a lot of different oils and viscositys. I've tried RL 5w-20, 5w-30, and 0w-30 and none of that had any effect. Neither did HPL's premium plus (which is their extreme cold weather oil) or "no vii". So far only HPL PCMO has made a difference, though even there it might be something else going on and just coincidental, I won't really know until I switch back to my batch of no vii for this summer.

 

[RamDiver]

There is no such thing. Oil is reaching every part of the engine at the same speed regardless of viscosity, unless you go way out of bounds and hit the pressure relief in the system. Beyond that, increasing viscosity just gives a tiny bump in oil pressure.

I noticed quite a remarkable difference during cold morning starts with my Tundra when I switched from 5W20 to 0W20 during the winter.

I'm referring to -20°C (-4°F) and below where it tended to crank a few times before starting with a bit of rattling sounds on the colder mornings.

Switching to the lower viscosity oil produced much easier and faster starts without any irregular noises. I can't imagine any other explanation other than reduced friction within the engine components.

I'm open to hearing any theories.

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[ramffml]

I noticed quite a remarkable difference during cold morning starts with my Tundra when I switched from 5W20 to 0W20 during the winter.

I'm referring to -20°C (-4°F) and below where it tended to crank a few times before starting with a bit of rattling sounds on the colder mornings.

Switching to the lower viscosity oil produced much easier and faster starts without any irregular noises. I can't imagine any other explanation other than reduced friction within the engine components.

I'm open to hearing any theories.

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I'm not suggesting that 0w doesn't work better in the cold, just that when it comes time to pressurize the engine, there is no difference in the amount of time it takes to do that with a positive displacement oil pump. This is according to the guys on bitog, I'm not just coming up with this myself. I'm not familar with the 5.7 in the tundra, I don't know what pump it uses.

 

[Burla]

My theory before the experiences on this board was the oil pump was a total equalizer as in it pumps at a certain rate and no difference between weights of oil. I no now believe that is wrong, I have no answer how this can be true and the manu experiences on this board with cold piston slap and how many of them solved it by going thinner.

 

[RamDiver]

I'm not suggesting that 0w doesn't work better in the cold, just that when it comes time to pressurize the engine, there is no difference in the amount of time it takes to do that with a positive displacement oil pump.

Our hemis use positive displacement oil pumps, these pumps don't pump faster or slower or less or more depending on viscosity, they pump the same amount with the only change being the PSI at which it pumps.

I'm no hydrodynamics expert but I would have thought that the increase in pressure resulting from using a higher-viscosity oil is a demonstration of a higher resistance to the flow through the engine cavity. This higher resistance might also contribute to a longer period of time before all surfaces are well coated.

I'm not saying this is the way it is but this is my understanding, right or wrong. Please share your thoughts on this concept.

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[Wild one]

I'm no hydrodynamics expert but I would have thought that the increase in pressure resulting from using a higher-viscosity oil is a demonstration of a higher resistance to the flow through the engine cavity. This higher resistance might also contribute to a longer period of time before all surfaces are well coated.

I'm not saying this is the way it is but this is my understanding, right or wrong. Please share your thoughts on this concept.

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Bearing clearances determine oil pressure more then the size of the oil passages,you're still forcing the same basic volumn of oil to the bearings. Piston slap is basically a non issue other then being slightly annoying,just listen to an engine running forged pistons and proper cylinder wall clearances ,they'll rattle till the piston gets some heat in it,and the clearances tighten up. I'd worry more about lifter rattle then i ever would about piston slap

 

[Wild one]

Johnson Lifters​

·
Gen3 Hemi PSA:
There is a counterbore at the top of SOME engine blocks, that caused an issue with our original design. This was brought to our attention a few years ago, and I changed the body to accommodate. First popped up on 6.2’s, then eventually 5.7’s and 6.4’s. I don’t necessarily understand why they did this…but that’s neither here nor there.
If you have one of these engine blocks, be sure you are using our latest design. If you use the old design you will have low oil pressure.
We’ve phased the old body out years ago, but thousands of sets had been sold prior to the change. If you wind up with the old design from one of our distributors, contact us and we’ll swap it out free of charge.
The pictures below show the lifter bore counterbore, as well as both old and new designs. The new design is on the right, with the lower seat height and oil feed oil detail. The latest design will also require a longer pushrod

 

[RamDiver]

Bearing clearances determine oil pressure more then the size of the oil passages,you're still forcing the same basic volumn of oil to the bearings. Piston slap is basically a non issue other then being slightly annoying,just listen to an engine running forged pistons and proper cylinder wall clearances ,they'll rattle till the piston gets some heat in it,and the clearances tighten up. I'd worry more about lifter rattle then i ever would about piston slap

Regardless of where the added pressure is created, would it not still be adding resistance to the oil flow and slowing the complete coverage of all surfaces?

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[Wild one]

Regardless of where the added pressure is created, would it not still be adding resistance to the oil flow and slowing the complete coverage of all surfaces?

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I don't know if that's the case.If 5W-20 creates 40 psi,and 5W-30 creates 45psi,wouldn't both be flowing the same volumn of oil to the bearings and the rest of the engine.

 

[ramffml]

My theory before the experiences on this board was the oil pump was a total equalizer as in it pumps at a certain rate and no difference between weights of oil. I no now believe that is wrong, I have no answer how this can be true and the manu experiences on this board with cold piston slap and how many of them solved it by going thinner.

I still believe your original theory is correct. I'm far from an expert, just going off of what I hear in my truck. All the 0w-30, 0w-40 and 5w-30 have sounded worse than my current batch of 5w-20, but the RL 5w-20 also did not sound any better than the 0w-x I've tried.

I think there is something else going on with respect to piston slap, possibly the formula itself rather than the viscosity?

Just guessing. I know that this is the first time I'm running a group 3 oil since like 5 years ago and maybe that is playing a role, all the worse sounding oils have been group 4. But that's just a note from left field, probably nothing to do with it either.

 

[ramffml]

Regardless of where the added pressure is created, would it not still be adding resistance to the oil flow and slowing the complete coverage of all surfaces?

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Picture a steam roller driving over a ketchup bottle with the cap open; that stuff is coming out whether it wants to or not. Now replace the contents with thick mollasses, same steam roller and bottle, the PSI at the bottle cap will increase but it's still going to come out at the same speed.

 

[RamDiver]

Picture a steam roller driving over a ketchup bottle with the cap open; that stuff is coming out whether it wants to or not. Now replace the contents with thick mollasses, same steam roller and bottle, the PSI at the bottle cap will increase but it's still going to come out at the same speed.

That's an interesting concept and a great analogy.

Thanks, now I need to study more about hydrodynamics.

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[ramffml]

That's an interesting concept and a great analogy.

Thanks, now I need to study more about hydrodynamics.

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Pretty sure I've saved a few bitog comments on my disk talking about this, I will try and look them up again, more than likely they came from a member named "ZeeOSix". Here is quick google search:

https://www.google.com/search?q=site%3Abobistheoilguy.com+"ZeeOSix"+positive+displacement+oil+pump

 

[BlackSheepRebel]

So this is more a Hemi issue than other engines?

yes. most agree it's a lifter design flaw, although no worse than, say, chevy's dod (mds) design flaw...just something to be aware of and potentially fix/mitigate if you care and are keeping the truck a long time. mds delete, more frequent oil changes, keep idle times low...

look for "reignited" on youtube. everyone has opinoins, some will agree/disagree, but lots of good content on this and other hemi issues.

 

[Burla]

I still believe your original theory is correct. I'm far from an expert, just going off of what I hear in my truck. All the 0w-30, 0w-40 and 5w-30 have sounded worse than my current batch of 5w-20, but the RL 5w-20 also did not sound any better than the 0w-x I've tried.

I think there is something else going on with respect to piston slap, possibly the formula itself rather than the viscosity?

Just guessing. I know that this is the first time I'm running a group 3 oil since like 5 years ago and maybe that is playing a role, all the worse sounding oils have been group 4. But that's just a note from left field, probably nothing to do with it either.

Not really, guys were getting massive relief 5w30 redline to 0w30 redline with near identical additive packages pre new forumula, and 5w30 redline to PUP anything. Mind you this is about cold piston slap and not hemi tick which is oiled different. I am doubting additives can correct something that far out of tolerances, with exception to perhaps something like mos2 which would actually fill in the gaps. No testing that I am aware of mos2 and piston slap, in theory perhaps? But thinner oils have worked since the first guy who reported this 2016hemiram or something sorry I forget the members avatar had this issue with 5w30 redline, which has been proven many times a suspect in cold piston slap. The bottom line, different oil strategies for different situations have proven effective for many or most rams, sadly not yours bbrother.

Fix hemi tick best you can is goal one, and "try" and avoid cold piston slap if you can. For each ram this might be a different product. Redlines decision to redo 0w30 really hurt the easy answer. Many reports new 0w30 redline ain't it. Maybe mixing redline 5w30 and some of their thinner stuff 0w20 or 5w20 is the "best" chance at getting both piston slap and tick away, kinda sucks if this is true, but it is what it is.

 

[ramffml]

Not really, guys were getting massive relief 5w30 redline to 0w30 redline with near identical additive packages pre new forumula, and 5w30 redline to PUP anything. Mind you this is about cold piston slap and not hemi tick which is oiled different. I am doubting additives can correct something that far out of tolerances, with exception to perhaps something like mos2 which would actually fill in the gaps. No testing that I am aware of mos2 and piston slap, in theory perhaps? But thinner oils have worked since the first guy who reported this 2016hemiram or something sorry I forget the members avatar had this issue with 5w30 redline, which has been proven many times a suspect in cold piston slap. The bottom line, different oil strategies for different situations have proven effective for many or most rams, sadly not yours bbrother.

Fix hemi tick best you can is goal one, and "try" and avoid cold piston slap if you can. For each ram this might be a different product.

That's what makes these noises so fun, everyone has different results. I really wished thinner oils worked for me, they don't which is why I've tried so many different variations. I solved my noisy valve train with the first batch of Redline I used, every oil change after (6 or 7 since then) has been a different brand and/or viscosity with the hope that it would fix the piston slap but nothing has worked until my current oil which is 5w-20. I've used RL 0w- 30. Not a single bit of difference.

It's even possible that the reports we're hearing on the board here are different noises. We all know how often "tick" is referred to for different things, possibly one or more of us are using "piston slap" for different noises as well.

But in any case, my original point was that a different viscosity won't change the speed at which the engine is pressurized and lubed or reaching the bearings (and piston slap isn't a bearing thing in the first place, it's just the piston contacting the cylinder wall). The time it takes to pressurize an engine is measured in seconds, but it can take 5+ minutes of idling before that noise clears up in my engine.

So if it was purely a viscosity thing that was helping because it reached a critical part of the engine sooner with thinner oil, then why would it still take 5+ minutes for the sound to go away when the engine is fully pressurized after a second or two? There is no way it's taking 5+ minutes for oil to reach some critical part?

 

[Burla]

If I had cold piston slap, my answer would be redline 5w30 plus a sump blanket. I would opt out of going thinner, I just believe for what it's worth the thin oil spec is responsible for many issues. No I don't have proof and acknowledge the many trucks that run 5w20 for 500k miles, but what we don't know is how many cam fails could have been prevented with a better strategy. We will never know that, just up to each guy and what makes sense to him.

 

[ramffml]

If I had cold piston slap, my answer would be redline 5w30 plus a sump blanket. I would opt out of going thinner, I just believe for what it's worth the thin oil spec is responsible for many issues. No I don't have proof and acknowledge the many trucks that run 5w20 for 500k miles, but what we don't know is how many cam fails could have been prevented with a better strategy. We will never know that, just up to each guy and what makes sense to him.

Like Wild One suggested, I don't think piston slap is a terribly destructive thing despite what it sounds like. GM's are known for this and they seem to run a long time despite it. If I did a lot of short trips I'd be more concerned, but I have < 100 idle hours and already at 60,000 miles so by my estimates it will wear out faster due to mileage than cold starts. It just bugs me, pay all that money for a new truck and it just ticks and knocks and clatters and pings its way through life. Drives me nuts.

Agreed though, I'm not planning on running 5w-20 forever. This was requested by my mechanic who was trying to help me fix my pinging issue. He said to try and run the "factory spec" and get back to him, well I got back to him and it's not fixing my ping so 5w-30 is going back in a month during my next change. But I'll probably stay with the same brand/formula I'm running now, might make a nice test next winter after my last "no vii" is used up, see if the piston slap comes back.