Oil Weight for built engine/Ideal oil pressures

Pennzoil motor oil
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Originally Posted By: Shannow
Theory eh ?

Exactly.
I stay out of your endless back and forth threads with Caterham for good reason; it's two opposing viewpoints with no 100% correct answer. No different really than two people arguing about whether or not God exists.

While others may gobble it up, posting tables, and then supplying your own interpretation and subsequent conclusions isn't impressive. But hey, it is novel to see you trotting out the Sommerfield (1904) solution, of which pressures are rarely encountered in real bearings.
Originally Posted By: Shannow
What we DO know is that the OP has lower then recommended oil pressure (for a stock engine, stock clearances, with OEM recommended grades)... from this, we can deduce that the clearances are opened up some.

In the rush to demonstrate what you believe, we do know that you got this one fundamental fact completely wrong. His oil pressure well exceeds the recommended level per the FSM data I provided.
 
Originally Posted By: Ramblejam
Originally Posted By: Shannow
Theory eh ?

Exactly.
I stay out of your endless back and forth threads with Caterham for good reason; it's two opposing viewpoints with no 100% correct answer. No different really than two people arguing about whether or not God exists.


Got to admit that ONE of us has an engineering background, textbook and experience (practical through having designed, built, and maintained bearings and their lubrication for a quarter century)...

there's science, and there's theology..."posits" and "beliefs" aren't science.
 
Originally Posted By: Ramblejam
Sure, but flow>pressure, as long as pressure is adequate.


OK, not misquoting you this time...what exactly about flow does the lubricating ?

Support that assertion with any data. PLEASE!

Not theory or conjecture.
 
Originally Posted By: Ramblejam
His oil pressure well exceeds the recommended level per the FSM data I provided.


Yes, it is above the minimum (it says 4.2psi or higher) oil pressure listed in the FSM. Any engine I've ever owned has been FAR above that figure. I think the one listed in the FSM for my 302 was like 5psi? It had 32 hot at idle on a 0w-20, 37 or so on a 0w-40 and that was with over 300,000km on it. This really isn't significant in any way other than acknowledging it is above the minimum. I've torn down engines that were above the minimum and had no bearings left in them (like the 302 my buddy owned) so I don't consider that an important point in this discussion.

What I DO consider important are two things:

1. Oil temperature
2. Power level

These are obviously related, but #2 also brings with it higher cylinder pressures which increase bearing load. So you have more load, with higher oil temperature, which both work to try and take the bearings out of the engine. You can install more oil cooling, increase sump volume....etc to bring #1 back down, but you still have #2 to contend with, so you would have to over-compensate with #1 to get you back to stock MOFT or, you can play it safe and just run a heavier oil, particularly if you aren't increasing oil cooling, which I have not seen any mention of from the OP.

It doesn't mean you need to run 10w-60, but if the OEM recommendation is 5w30, stepping up to something with a bit higher HTHS if you've increased power level above stock is the logical choice. This is the same reason my SRT-8 requires 0w-40 instead of the 5w-20 my wife's R/T specs, it is the same reason Ford did the 5w-50 thing with the Track Pack. Oil temperature is important, and increased power levels drive higher oil temperatures.
 
Originally Posted By: OVERKILL
so I don't consider that an important point in this discussion.

Nor do I consider discussing 302's, and what Ford or Chrysler are doing to be of any point here; these thick/thin debates that Shannow, Caterham and yourself get into always do this, and it's another reason why I avoid them.

The facts (not theory and comparison) are these.

Engine is a 4G63T
His oil pressure far exceeds minimums, and matches what most 4G63T guys are getting with 20w-50 (whether you place any importance on this is of personal opinion).
Clearances are .0018 rod/.0023 main

At these clearances, loads are well distributed (elastic journal deformation = bearing curvature). Subsequently, peak oil film pressure is low, and minimum oil film thickness is high.

Originally Posted By: Shannow
OK, not misquoting you this time...what exactly about flow does the lubricating ?

If a thinner oil still avoids asperity contact, but sees lower temperatures and less friction...
 
Originally Posted By: Ramblejam
Originally Posted By: Shannow
OK, not misquoting you this time...what exactly about flow does the lubricating ?

If a thinner oil still avoids asperity contact, but sees lower temperatures and less friction...


Again, that's the MOFT...all you know with more cylinder pressure, more bearing clearances and thinner oil is that the MOFT is thinner...there is no way of telling how far away you are from asperity contact, thus my recommendations to push things back in the direction of MAINTAINING MOFT.

Less friction doesn't mean less wear, as the onset of boundary lubrication is the lowest friction regime, but definitely NOT the lowest wear regime.

Again...what exactly in "flow" does the lubricating ?
 
Originally Posted By: Shannow
Again...what exactly in "flow" does the lubricating ?

I've answered your question. You don't like the answer provided, and that's of no concern to me; continue the argument with Caterham for a few more years. You have your beliefs/theories, and no amount of discussion is going to sway you from those.

As I said, just like two people arguing about God...
 
Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
so I don't consider that an important point in this discussion.

Nor do I consider discussing 302's, and what Ford or Chrysler are doing to be of any point here; these thick/thin debates that Shannow, Caterham and yourself get into always do this, and it's another reason why I avoid them.


Engines are engines. Of course what Ford, Chrysler, Mitsubishi, BMW, Toyota....etc are doing is relevant. This is because they (the OEM's) ALL do the same thing: When power levels go up, they increase the viscosity of the oil and/or increase oil volume and oil cooling. That's what is in play here and that's why I've brought it up. You can dismiss it all you want but it doesn't make it any less relevant.

Originally Posted By: Ramblejam
The facts (not theory and comparison) are these.

Engine is a 4G63T
His oil pressure far exceeds minimums, and matches what most 4G63T guys are getting with 20w-50 (whether you place any importance on this is of personal opinion).
Clearances are .0018 rod/.0023 main

At these clearances, loads are well distributed (elastic journal deformation = bearing curvature). Subsequently, peak oil film pressure is low, and minimum oil film thickness is high.


At those clearances we know what his oil pressure is. That's all we know. We don't know whether this is an aftermarket high volume oil pump. We don't know what cylinder pressures he's running; how much higher than stock they are. We don't know what his oil temperature is, because he hasn't posted it. We don't know what his maximum oil temperature is, again, because he hasn't posted it. What we DO know is that the engine is modified and making MORE power than stock. More power means higher cylinder pressures, temperatures and bearing loads, which in turn means higher oil temperatures, which in turn requires more viscosity reserve to maintain MOFT. That's not theory, that's fact. I don't care what the minimum oil pressure spec for the engine is, I guarantee you if he runs it on WD40 until the bearings are worn that he can hit that magic number, but that doesn't a healthy engine make. Are you going to pay for a new engine if he embarks upon that experiment?

Viscosity is almost always increased when power is increased in OEM applications to deal with the POTENTIAL for failure due to elevated oil temperatures. That is, unless there are thermostatic devices in place to reduce power to compensate for viscosity loss. You are more than welcome to play Russian Roulette with your own engines but to advocate such an approach for a new member is reckless and irresponsible.

I find it somewhat comical that you have engaged in this discussion as you have, and aided in it getting as heated as it has, then indicating that this was something you were already wary of due to past feedback. Yes, these topics tend to get heated, and I generally skip over them too unless I see something that worries me, which is what I saw here. When dealing with an engine making higher than stock power levels, going up, even if only slightly, from the stock viscosity recommendation is the safe approach. I'm not advocating a heavy lubricant, simply one with a higher HTHS than the GF-5 stock spec, which should provide similar reserve to what the OEM-spec lubricant provided at the stock power level.
 
Originally Posted By: OVERKILL
Engines are engines. Of course what Ford, Chrysler, Mitsubishi, BMW, Toyota....etc are doing is relevant.


I'll strongly disagree with that opinion.

Originally Posted By: OVERKILL
You are more than welcome to play Russian Roulette with your own engines but to advocate such an approach for a new member is reckless and irresponsible.


Your "new member" has been here over a year.

Show me where I advocated for "such an approach"; I requested that an individual support an assertion with data.

Originally Posted By: OVERKILL
I find it somewhat comical that you have engaged in this discussion as you have, and aided in it getting as heated as it has, then indicating that this was something you were already wary of due to past feedback.

I'll entertain it for a little while (this evening). Then, I'm out, and as I said, you guys can continue the back-and-forth for years to come.
 
Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
Engines are engines. Of course what Ford, Chrysler, Mitsubishi, BMW, Toyota....etc are doing is relevant.


I'll strongly disagree with that opinion.


I see you did what you accused Shannow of and omitted the rest of my statement eh?

Originally Posted By: Ramblejam

If you're going to quote me, do so with the full quote...don't parse it in lame attempt to make it appear I said something I didn't.


Bravo on the above good sir, bravo. Nothing like an excursion in the hypocritical to really bring some credit to the discussion
wink.gif


Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
You are more than welcome to play Russian Roulette with your own engines but to advocate such an approach for a new member is reckless and irresponsible.


Your "new member" has been here over a year.


Yes, and has a whopping 7 posts including those made in this thread.

Originally Posted By: Ramblejam
Show me where I advocated for "such an approach"; I requested that an individual support an assertion with data.


You posted the MINIMUM acceptable spec for the engine as if this was a target (it isn't) and then took issue with a guy who advocated him running a heavier than stock lubricant. Taking issue with him in running a heavier than stock lubricant leaves us where exactly? At stock spec viscosity, no?

Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
I find it somewhat comical that you have engaged in this discussion as you have, and aided in it getting as heated as it has, then indicating that this was something you were already wary of due to past feedback.


I'll entertain it for a little while (this evening). Then, I'm out, and as I said, you guys can continue the back-and-forth for years to come.


This is entertainment potentially at the expense (literally) of a member soliciting advice. Again, this is why I took issue with your questioning of the heavier than stock recommendation. It doesn't have to be much heavier than stock, but it is certainly the safe direction to go when dealing with higher than stock power levels and a plethora of unknowns.
 
Originally Posted By: OVERKILL
I see you did what you accused Shannow of and omitted the rest of my statement eh?
smirk.gif
Well done.


The relevance is the same. You think you're right. I think you're wrong. End of story.

Originally Posted By: OVERKILL
Taking issue with him in running a heavier than stock lubricant leaves us where exactly? At stock spec viscosity, no?


I appear to be the only one here who actually listened to the OP and asked for supporting data for deviations, versus rushing to show everyone what I believe or draw analogies to what OEM's are doing for factory fill.

Originally Posted By: Only1Hockeytown
but I'm thinking that at 5w30, those oil pressures are pretty fine and I wouldn't want to go for a thicker oil, in fact I could almost go to a thinner oil.
 
Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
I see you did what you accused Shannow of and omitted the rest of my statement eh?
smirk.gif
Well done.


The relevance is the same. You think you're right. I think you're wrong. End of story.


Yes, but I'm not gambling with the life of his engine with my recommendation, you are. That's the difference. That is, your implication that he could go spec viscosity or thinner as per his posit is more dangerous than my recommendation that he run a 0w-40 or something that meets the common Euro lube >3.5cP HTHS spec, which will inherently have a greater tolerance for the higher oil temperatures his increased power level will generate, not knowing anything more about his setup than we currently do.

Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
Taking issue with him in running a heavier than stock lubricant leaves us where exactly? At stock spec viscosity, no?


I appear to be the only one here who actually listened to the OP and asked for supporting data for deviations, versus rushing to show everyone what I believe or draw analogies to what OEM's are doing for factory fill.

Originally Posted By: Only1Hockeytown
but I'm thinking that at 5w30, those oil pressures are pretty fine and I wouldn't want to go for a thicker oil, in fact I could almost go to a thinner oil.



He is assuming, and you basically supported, that, based on oil pressure, that factory spec is adequate, and that he could go lower. Again, this brings with it no mention of maximum oil temperatures, how much power more than stock he is making, whether he has a high volume oil pump (which would increase observed pressure)....etc. There are a lot of unknowns and based only on what we DO know, which is that he has a built engine with higher output and factory dimensions, the safe recommendation is always to increase, not decrease, viscosity.

IF he mentioned he had a massive aftermarket oil cooler, that would change my recommendation. Same with him increasing sump volume. Both of those things have not been mentioned however.

What the OEM's are doing is covering their behinds, which is why it is important to pay attention to them. They have done the testing and when they make a deviation from what they have been doing or change something out, there is a (financially relevant) reason for them doing so. And it usually has to do with higher failure rates, which cost them money. They don't go around changing out specs (particularly to heaver oils due to CAFE) because it is the fun thing to be doing.
 
Originally Posted By: OVERKILL
Yes, but I'm not gambling with the life of his engine with my recommendation, you are. That's the difference.

Because as everyone knows with the Evo9 (be it stock, or "built")...

SAE 30 - Boom
15.gif

SAE 40 - Nirvana
grin.gif
 
Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
Yes, but I'm not gambling with the life of his engine with my recommendation, you are. That's the difference.

Because as everyone knows with the Evo9 (be it stock, or "built")...

SAE 30 - Boom
SAE 40 - Nirvana


See more recent edit please for greater clarification.

However, if he ends up needing an HTHS of 3.3cP to keep parts separated under high boost and elevated oil temperatures and the GF-5 5w30 is 3.0, then yes, that would be the difference. That's the gamble of not knowing enough about the setup. That's the difference between a safe recommendation and one that isn't. That's what I've been driving at here and where the intentionally conservative OEM recommendations point us.
 
Originally Posted By: OVERKILL
See more recent edit please for greater clarification.

However, if he ends up needing an HTHS of 3.3cP to keep parts separated under high boost and elevated oil temperatures and the GF-5 5w30 is 3.0, then yes, that would be the difference. That's the gamble of not knowing enough about the setup. That's the difference between a safe recommendation and one that isn't. That's what I've been driving at here and where the intentionally conservative OEM recommendations point us.


Again, you're relying on theory, guesswork, and analogies as the basis of your argument; this is the fundamental flaw.

There is no concrete evidence (running through used oil analysis over on evolutionm.net) to support the notion of needing a thicker oil in stock, or "built" Evo9's; this is why I requested data from you here that would run counter to what's presented there.
 
Originally Posted By: Ramblejam
Originally Posted By: OVERKILL
See more recent edit please for greater clarification.

However, if he ends up needing an HTHS of 3.3cP to keep parts separated under high boost and elevated oil temperatures and the GF-5 5w30 is 3.0, then yes, that would be the difference. That's the gamble of not knowing enough about the setup. That's the difference between a safe recommendation and one that isn't. That's what I've been driving at here and where the intentionally conservative OEM recommendations point us.


Again, you're relying on theory, guesswork, and analogies as the basis of your argument; this is the fundamental flaw.

There is no concrete evidence (running through used oil analysis over on evolutionm.net) to support the notion of needing a thicker oil in stock, or "built" Evo9's; this is why I requested data from you here that would run counter to what's presented there.


First off, I wouldn't consider needing a heavier oil in a stock engine, so we can dismiss that one. Secondly, I wouldn't consider used oil analysis "data", we would need tear-downs, if you have tear-down data, I would love to see it. Thirdly, this is not guesswork, this is standard process in the industry which can be readily observed by looking at any of the OEM's who build performance engines, as their goal is longevity first and foremost; they don't want warranty claims. This (increased viscosity) also aides in dealing with viscosity loss through fuel dilution, something also present in factory (conservative/safe) tunes. Show me an OEM who builds a performance engine that spec's a lower viscosity than its pedestrian sibling. There are GM owners manuals that tell you to step up to a heavier oil if you intend on partaking in track time with your vehicle.

The flaw in your logic is you think I'm making an argument, I'm not. This is how the industry works. Performance engines; engines that develop more power than their non-performance oriented siblings, generally spec heavier oil, sometimes have increased sump volume and usually have increased oil cooling. Often there are a combination of these things. You can play contrary to your heart's content, and I welcome it, but at the end of the day, there is example after example of this playing out in the industry where this stuff is actually tested and we aren't dealing with forum nonsense. Where warranty claims are important and they don't want engines blowing up. I don't want the OP's engine to blow up, so I suggested something conservative; something slightly heavier than OEM spec, factoring in the ambiguity of his application; the significant lack of data presented on his build. All you've done is post a table for the minimum acceptable oil spec and taken others to task over recommendations that, while not ideal, are not going to cause harm to the OP's engine either. I certainly hope that's not your idea of a successful evening, as you've branded this as entertainment and it seems that, by extension, you'd rather just stir up faeces for no reason other than to get the attention of a few key members, not actually aide the OP in any way.
 
Originally Posted By: OVERKILL
I certainly hope that's not your idea of a successful evening, as you've branded this as entertainment and it seems that, by extension, you'd rather just stir up faeces for no reason other than to get the attention of a few key members, not actually aide the OP in any way.


LOL, I think you've picked it...

Originally Posted By: Ramblejam
Caterham


Originally Posted By: Ramblejam
Caterham


Originally Posted By: Ramblejam
Caterham


Given that he hasn't posted in the thread, and been brought up by the same guy 3 times

Is it like saying BeetleJuice three times and he appears ?
 
I've built a few engines in my day. Not this specific one, but plain bearings are pretty much the same up to about 8,000 RPM... Are you going above that?

With the clearances you provided I'd start at 40 grade oil. Mono, multi, whatever floats your boat. Then I'd be looking for bearing metal indicators in used oil analysis or any sign of non-magnetic sheen in the oil on drain. I'd keep the change intervals short, like 2,500 miles, until I had a lab tell me that all is well.

5W-40 ~ 15w40 makes no difference to me. It's the hot viscosity I'm concerned about.

How is this motor at aerating oil in the sump? What have other machinists of similar built engine indicated works best?

Is this motor going to see short bursts of power like in drag racing, or hours in the high HP zone like track days?
 
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