Is it time to change oil viscosity?

[Ttype6]

I have a 1986 GN with around 108,000 miles on it. I'm using the factory suggested 10w-30 and have about 70 psi oil pressure when cold, but once it heats up the pressure drops to only about 17-18 psi. Should I switch to 10w-40 or 20w-50?

I don't know what oil you're currently running but I do know two things about it, it's much more expensive than Quaker State full synthetic 5W-30 when purchased at Walmart and it has less film strength. It's a no-brainer. Perhaps you're concerned about running a synthetic oil and having it cause an oil leak and that is a real concern. In that case, you might be interested in Quaker State all mileage 10w 40. It has an impressively high film strength of over 126,000 PSI and it's a conventional oil. It has the highest PSI strength of any conventional oil that 540 rat has tested to date. I don't recommend that you run a thicker oil, I recommend you run Quaker State 5W30 full synthetic. But I do understand there are some concerns about oil leaks.

 

[LANDAU LIMITED]

If you want to base your oil choice on some guy on the internet rubbing ball bearings together so be it. He's also the same guy who said if you run Quaker State you don't need to break in a flat tappet cam. Just fire it up and go with no break in lube on the cam. I just picked up a voodoo cam for cheap I'm thinking of trying that. If it works I'll jump on the 540rat bandwagon, until then I'm skeptical.

 

[turbocamino1]

If you want to base your oil choice on some guy on the internet rubbing ball bearings together so be it. He's also the same guy who said if you run Quaker State you don't need to break in a flat tappet cam. Just fire it up and go with no break in lube on the cam. I just picked up a voodoo cam for cheap I'm thinking of trying that. If it works I'll jump on the 540rat bandwagon, until then I'm skeptical.

Interesting take ..it is a very very long read..curious how much you read? Tests are test..they have results..some methods are more definitive than others .. deny all you like..but rocks are hard and water is wet. Some things ARE surely fact.

 

[LANDAU LIMITED]

Interesting take ..it is a very very long read..curious how much you read? Tests are test..they have results..some methods are more definitive than others .. deny all you like..but rocks are hard and water is wet. Some things ARE surely fact.

I've been watching 540Rat go back and forth with many people over the last 20 years on many different forums. I've also read a ton of literature he has written. I just take it with a grain of salt, I actually use one of the higher rated oils on his list. I REALLY want to test his theory on flat tappet break in just for grins.

 

[Mr.Spool]

Again, that's not to say that you can't get a thick oil that has high film strength but you can't attribute its film strength to the viscosity, it's attributed to the additive package

So you don't believe viscocity

Engine builders and doctors like the rest of us are human beings and the thing that Hitler learned from Lennon is that a lie told often enough becomes the truth and we are all susceptible to that. Engine builders believe the same wives tales that most all of us do. Thick oils do not protect engine parts better than thin oils. Film strength is what does that and the higher that it is the more protection you have. They do allow the oil pressure to stay higher at hot idle but again if your oil pressure comes below something that you're comfortable with that's when you need a high volume oil pump. There's another thing that most all thicker oils tend to have in common and do better generally speaking than thinner oils and that is that they tend to have a typically much higher temperature at which the onset of thermal breakdown starts to occur. There is also a third thing that I can think of that thick oils consistently do better than thin oils and that is that when you run a thicker oil, the engine will burn less oil. Oil pressure, thermal breakdown, and oil consumption are the only three things that improve when you use thicker oils and they improve just about every time. Film strength is not improved by higher viscosity nor is it improved by zddp and the common myth is that both of those things improve film strength but it's just not true. Again, that's not to say that you can't get a thick oil that has high film strength but you can't attribute its film strength to the viscosity, it's attributed to the additive package. There's no reason why thicker oils couldn't be some of the most protective oils but in real life when you measure their film strength most all of them fall short except for one, amsoil 10w50 dirt motorcycle oil which has a film strength of 134,968 PSI and is the number six oil in 540 rats oil film strength list. The number 11 highest strength oil is Quaker State full synthetic 5W30 with a PSI reading of $133,302. The next highest 50 weight motor oil on the list comes in at number 35 and it's amsoil signature series synthetic 5w50 with a PSI strength of 118,543. In the 249th position on his list is mobile one synthetic 15w50. I don't know if this is the same one that you use but it has a film strength of 70,235 PSI and that's not good. And of course the 10w50 amsoil dirt motorcycle oil is 18 or 19 dollars a quart. It will do all the things that a thick oil does for you currently but it also has incredible film strength.

Viscosity also determines film strength by the thickness
Your saying its not (unless thats a typo).
That alone effects the protection especially in the heat.
Which I believe is how these 15/20 50s oils are recommended for.
Not just extreme pressures but for heat as well

 

[Mr.Spool]

Again, that's not to say that you can't get a thick oil that has high film strength but you can't attribute its film strength to the viscosity, it's attributed to the additive package.

Think this is where people get hung up.
The additive package is the way to get higher on the vi scale that's why Dino oil has a lower number than a synthetic from how I understand it.
Think the hangup is where you don't believe viscocity increases film strength.
Thicker oils create a thicker film strength is how I understand it
I could be wrong but there are plenty of sources that acknowledge this relationship.
I feel I am no oil expert just throwing it out there
I've used alot of different oils over the years and I don't use high end fancy anymore the Walmart stuff works on big power.
The pure methanol cars do run the special green stuff lol and its far from cheap

 

[Mr.Spool]

higher viscosity

The engines resistance to flow is supposed to play a key role.
That's also why I run the 15/20w 50 oil

 

[Turbo6inKY]

The pure methanol cars do run the special green stuff lol and its far from cheap

Methanol draws in water and it gets really corrosive, and most pure-methanol builds run REALLY rich, so a lot of it ends up in the oil. It takes a special additive package to manage that.

 

[Mr.Spool]

Methanol draws in water and it gets really corrosive, and most pure-methanol builds run REALLY rich, so a lot of it ends up in the oil. It takes a special additive package to manage that.

I get it
I've lived it

 

[Ttype6]

If you want to base your oil choice on some guy on the internet rubbing ball bearings together so be it. He's also the same guy who said if you run Quaker State you don't need to break in a flat tappet cam. Just fire it up and go with no break in lube on the cam. I just picked up a voodoo cam for cheap I'm thinking of trying that. If it works I'll jump on the 540rat bandwagon, until then I'm skeptical.

He actually recommends using STP oil treatment as an assembly lube. If you're not being sarcastic and you do this you'll be one of many to find out the truth. Break in oils are oils that have very low film strength and they do it purposefully and the theory is to let all this stuff rub together and marry each other which has never made any sense to me. Why do you want pieces of metal to rub together and Gall each other?

Those ball bearing tests are just as stupid today as they've always been. They don't simulate anything that goes on in an engine and there's no engine oil that can prevent the damage that happens in one of those tests and you have no reason to say that he uses that kind of testing because he doesn't tell anybody how he measures film strength. He definitely doesn't measure it that way.
I would imagine just like everybody else and myself included that you've never seen a YouTube video where someone just puts oil in a flat tappet cammed engine that's been freshly rebuilt and starts it up and lets it idle, but you've heard over and over and over again about how important the break and procedure is and oh my God you've got to run the engine at exactly at 2,000 rpms. I always thought that was a bunch of crap and it is and it always will be and the worst part of it is using a very unprotective oil in the process. When you hear this procedure repeated over and over and over again you can't imagine even trying to start a new engine without break in oil and that ridiculous break in procedure. Propaganda is a very powerful thing.

 

[Ttype6]

Methanol draws in water and it gets really corrosive, and most pure-methanol builds run REALLY rich, so a lot of it ends up in the oil. It takes a special additive package to manage that.

Methanol draws in water and it gets really corrosive, and most pure-methanol builds run REALLY rich, so a lot of it ends up in the oil. It takes a special additive package to manage that.

The best additive packages in the best oils can only handle so much water carbon and alcohol and that's why we have recommended oil change intervals. As we put more and more of that stuff in our oils and we absolutely do in forced induction engines, we don't hunt for oils with different attitudes, we simply change the oil more often. It's one of the many ways that we motorheads waste money. I've said it over and over again, we're some of the most foolish people on the planet.

There is no quality that an additive package creates that's more important to film strength. Everything else takes a backseat to that and the very great majority of people have no idea what the film strength of their oil is.

 

[Ttype6]

Think the hangup is where you don't believe viscocity increases film strength.
Thicker oils create a thicker film strength is how I understand it

The real hang up is that people believe thicker oils create higher film strength and that is absolutely not true and the majority of motorheads believe that to be true because it's repeated over and over again. Film strength is created in the additive package, not the base oil as Brad Penn would have you believe and their oils have some of the lowest film strength. If thicker oils created More film strength then the oils in 540 rats blog with the highest viscosity would have the highest film strengths, but they don't. The thinner oils on his list, typically 5W-30 have the highest film strength. Can we say that the thinner the oil is the higher the film strength? Absolutely not. It's the additive package. The most powerful Corvette engine currently produced comes from the factory with thin oil.

 

[LANDAU LIMITED]

He actually recommends using STP oil treatment as an assembly lube. If you're not being sarcastic and you do this you'll be one of many to find out the truth. Break in oils are oils that have very low film strength and they do it purposefully and the theory is to let all this stuff rub together and marry each other which has never made any sense to me. Why do you want pieces of metal to rub together and Gall each other?

Those ball bearing tests are just as stupid today as they've always been. They don't simulate anything that goes on in an engine and there's no engine oil that can prevent the damage that happens in one of those tests and you have no reason to say that he uses that kind of testing because he doesn't tell anybody how he measures film strength. He definitely doesn't measure it that way.
I would imagine just like everybody else and myself included that you've never seen a YouTube video where someone just puts oil in a flat tappet cammed engine that's been freshly rebuilt and starts it up and lets it idle, but you've heard over and over and over again about how important the break and procedure is and oh my God you've got to run the engine at exactly at 2,000 rpms. I always thought that was a bunch of crap and it is and it always will be and the worst part of it is using a very unprotective oil in the process. When you hear this procedure repeated over and over and over again you can't imagine even trying to start a new engine without break in oil and that ridiculous break in procedure. Propaganda is a very powerful thing.

Hopefully I'll do that test. The first time I heard that and saw everyone go off on him I thought this isn't that hard to confirm. I gotta do this someday. I have most of the parts now just no time...some day. I'll have to remember the STP thing.

 

[Ttype6]

Hopefully I'll do that test. The first time I heard that and saw everyone go off on him I thought this isn't that hard to confirm. I gotta do this someday. I have most of the parts now just no time...some day. I'll have to remember the STP thing.

Absolutely something I would love to do as well. And even though the evidence says it will work, because of the effects of propaganda I'll be very nervous because propaganda without evidence affects everybody and that's why so many let Democrats violate their constitutional rights which are crimes that have gone unpunished. Apparently it is a violation of the highest law of the land for politicians to stop you from exercising your constitutional rights but it's not against the law for you to freely give them up. It is propaganda and the fear it causes without evidence from politicians who were formally referred to as a necessary evil and are some of the biggest liars on the planet that caused people to get the covid vaccine which isn't actually a vaccine but don't you worry, more facts come out everyday about what actually happened which was predicted by many but we still have the same problem in that the Democrat news media will not report on it. If you want to find out about what actually happened and has been recorded / AKA evidence you can find it just like you can find the truth out about engine oils but you have to look at the evidence and real life results and not believe unproven theories and the great majority of people won't do that, but if you do this thing you'll know the truth and the truth shall set you free. I have a block, crank, rods, oil pan, a front cover and a flywheel. I feel like I'd be in a much better position if all I had were Pistons and a cam and some lifters especially since the prices are so high now.

 

[LANDAU LIMITED]

Absolutely something I would love to do as well. And even though the evidence says it will work, because of the effects of propaganda I'll be very nervous because propaganda without evidence affects everybody and that's why so many let Democrats violate their constitutional rights which are crimes that have gone unpunished. Apparently it is a violation of the highest law of the land for politicians to stop you from exercising your constitutional rights but it's not against the law for you to freely give them up. It is propaganda and the fear it causes without evidence from politicians who were formally referred to as a necessary evil and are some of the biggest liars on the planet that caused people to get the covid vaccine which isn't actually a vaccine but don't you worry, more facts come out everyday about what actually happened which was predicted by many but we still have the same problem in that the Democrat news media will not report on it. If you want to find out about what actually happened and has been recorded / AKA evidence you can find it just like you can find the truth out about engine oils but you have to look at the evidence and real life results and not believe unproven theories and the great majority of people won't do that, but if you do this thing you'll know the truth and the truth shall set you free. I have a block, crank, rods, oil pan, a front cover and a flywheel. I feel like I'd be in a much better position if all I had were Pistons and a cam and some lifters especially since the prices are so high now.

Damn, that took a RIGHT turn real quick!

 

[Ttype6]

Damn, that took a RIGHT turn real quick!

Damn, that took a RIGHT turn real quick!

Not at all, it's added comment on the consistent theme of propaganda and it's influence without evidence.

Damn, that took a RIGHT turn real quick!

Have you ever started up a freshly rebuilt engine with a flat tap at cam in it?

Damn, that took a RIGHT turn real quick!

Tappet

 

[LANDAU LIMITED]

Not at all, it's added comment on the consistent theme of propaganda and it's influence without evidence.

Have you ever started up a freshly rebuilt engine with a flat tap at cam in it?

Tappet

It's called a joke, going from flat tappet cams to Democrats.

Yes I've started up plenty of engines with flat tappets.