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The Goods On Oils

PHaT MR30

By PHaT MR30,
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djr81 Grand Master

djr81

Posted
Posted
Pressure is directly proportion to viscosity, the thicker it is the higher is the pressure. This also mean higher pressure will have lower flow rate. You need both flow rate and pressure to fully optimize the operation of the oil system. IMO 50wt oil is just too thick for most application except racing or autocross....

Rather than start an argument I would rather pose a question.

First things first what you have said is partly correct. A higher viscosity fluid will create a larger pressure difference when measured from one end of the pipe it is being pumped in to the other. This means a higher output pressure at the pump is required to achieve the same flow rate.

BUT

There is more than one type of pump. For a centrifugal pump (like your water pump) the output pressure has a huge effect on the flow rate of the pump. For a positive displacement pump it has ABSOLUTELY no effect.

So what type of pump is your oil pump?

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scotty nm35
scotty nm35

Any brand will work fine, some just last longer than others. I still believe you are better off using a cheaper ($50) oil and changing it every 5k rather than spending twice that and trying to strin

Kinks
Kinks

Royal Purple 10W-50, warm it between your hands for a few seconds then apply it to the area at the base of your shaft between your balls ..about as valid as any other opinion in this thread

scotty nm35
scotty nm35

F1 still use monograde 10 weight oils, hence the need to get the engine warm before starting it. Nothing stone age about it...

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Cubes Grand Master

Cubes

Posted
Posted
Rather than start an argument I would rather pose a question.

First things first what you have said is partly correct. A higher viscosity fluid will create a larger pressure difference when measured from one end of the pipe it is being pumped in to the other. This means a higher output pressure at the pump is required to achieve the same flow rate.

BUT

There is more than one type of pump. For a centrifugal pump (like your water pump) the output pressure has a huge effect on the flow rate of the pump. For a positive displacement pump it has ABSOLUTELY no effect.

So what type of pump is your oil pump?

It does when the bypass is wide open; in essence the thicker oil creating high pressure also causes a huge effect on the flow rate of the pump as it has to dump a lot more oil to hold its specified oil pressure.

With a 5w40 I see ~90-95psi of oil pressure over 3500rpm.

LatinR33 Experienced

LatinR33

Posted
Posted

Nah i'll never take the odometer reading as gospel hehe. I just want to know if its a safe things to use. Ive been going through this thread and man ive got a headache and I just want to know what oil to buy tonight when i go down to supercheap. I just want something good quality and something quietens down my lifters abit during start up thats it. any suggestions for my 1996 R33?? Im sure its not rocket science but after reading a few pages im like damnnn oil choice is a massive decision.

SS8_Gohan Grand Master

SS8_Gohan

Posted
Posted

yeah, you've asked quite a few times :(

I've answered with Mobil 1 a few times as well :P

0w40 in my car, took a little less than 5 litres i think. As i've said before, RB lifters are fairly noisy anyway, but the Mobil 1 did quiet them down a little, for me. NEO R34, don't know if that makes a difference.

i can't say anymore than what i've already said. I've got 0w40 in my car, and yes it made the lifter less noisy.

can't answer your question any more straight forward than that. And if people like Trex101 are telling you it's fine, that it's 100% cool. They're the sorts of people in this thread that i made my oil choices from. Trex101 and khunjeng, etc...

SS8_Gohan Grand Master

SS8_Gohan

Posted
Posted

that's cool :(

mate, i was exactly the same, worrying about which oil to put, concerned about this and that. But some of guys in this thread REALLY know their oils. Mobil 1 is a good starting point, at a reasonable price and having 0w40 is fine. Then you can go German Castrol, Redline, Motul after that if you're keen.

i know exactly what it's like to be paranoid bout the car, especially with the oils. I also did my gearbox and diff at the same time, so i was 3 times as paranoid! haha

Maybe just PM Trex101 or khunjeng with your EXACT concerns and worries, and grab their opinion :P

adzR34 Collaborator

adzR34

Posted
Posted
nope, will still be cheaper i'm pretty sure :rofl: Even melb people have to pay for postage. The difference isn't that great between posting here or interstate.

ah okay yeh ive found those rates they aint that bad...

Pretty keen on the royal purple stuff for that price, anyone using this in theyre cars?

Hotwire Veteran

Hotwire

Posted
Posted

Guys,

Was just enquiring about gearbox oils at the Outlaw Speed Shop here in Adelaide, and got to talking about engine oils too. I was passed on this article to read/keep and had to share with everyone as it has some REAL eye openers.

I will more than likely be using the Royal Purple next, far and above the others for value for money I reckon. Almost makes me want to dump the Motul 8100 excess in there now!. However got to say that the Valvoline shocked me!

Cheers

Lee

Oil_Compar.pdf

Hotwire Veteran

Hotwire

Posted
Posted (edited)

Well I didnt get a price from Outlaw, but the listed price in the comparo is $79.99 compared to $92.99 for the Motul 8100 Excess, which you can get for cheaper than that.

By value for money, i meant for similar dollars to Motul, get far better protection for a full synthetic.

For a Semi synthetic, seems the Valvoline durablend is the go.

Its all in the PDF I attached to my post ;)

Edited by Hotwire
Trex101 Collaborator

Trex101

Posted
Posted
Guys,

Was just enquiring about gearbox oils at the Outlaw Speed Shop here in Adelaide, and got to talking about engine oils too. I was passed on this article to read/keep and had to share with everyone as it has some REAL eye openers.

I will more than likely be using the Royal Purple next, far and above the others for value for money I reckon. Almost makes me want to dump the Motul 8100 excess in there now!. However got to say that the Valvoline shocked me!

Cheers

Lee

This article from StreetCommodore is very misleading, this Timken test are only good for grease, not oil. The editor has admitted the test is flawed and not representatives of actual engine condition.

StreetCommodore reply:

http://www.streetforce.com.au/news/01_oils_aint_oils.php

Trex101 Collaborator

Trex101

Posted
Posted
Wow,

Thanks for pointing that out. So the verdict is still out then LOL

You know, i can get better wear reading with head and shoulder shampoo then all these oil tested. The chorine in there are a very good extreme pressure additives, it just that when you include it in your engine oil combine with moisture, you will form hydrochloride acid.

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