Jump to content
SAU Community

Recommended Posts

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?

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.

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.

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...

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

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?

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

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
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

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.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Lucky man, who owns it in the family? Any pics? 
    • The engine stuff is Greg Autism to the Max. I contacted Tony Mamo previously from AFR who went off to make his own company to further refine AFR heads. He is a wizard in US LS world. Pretty much the best person on earth who will sell you things he's done weird wizard magic to. The cam spec is not too different. I have a 232/234 .600/603 lift, 114LSA cam currently. The new one is 227/233 .638 .634. The 1.8 ratio roller rockers will effectively push this cam into the ~.670 range. These also get Mamo'ified to be drilled out and tapped to use a 10mm bolt over an 8mm for better stability. This is what lead to the cam being specced. The plan is to run it to 6800. (6600 currently). The Johnson lifters are to maintain proper lift at heavy use which is something the LS7's supposedly fail at and lose a bit of pressure, robbing you of lift at higher RPM. Hollow stem valves for better, well everything, Valve train control. I dunno. Hollow is better. The valves are also not on a standard valve angle. Compression ratio is going from 10.6 to 11.3. The cam is smaller, but also not really... The cam was specced when I generated a chart where I counted the frames of a lap video I had and noted how much of the time in % I spent at what RPM while on track at Sandown. The current cam/heads are a bit mismatched, the standard LS1 heads are the restriction to power, which is why everyone CNC's them to get a pretty solid improvement. Most of the difference between LS1->LS2->LS3 is really just better stock heads. The current cam is falling over about 600rpm earlier than it 'should' given the rest of my current setup. CNC'ing heads closes the gap with regards to heads. Aftermarket heads eliminate the gap and go further. The MMS heads go even further than that, and the heads I have in the box could quite easily be bolted to a 7.0 427ci or 454 and not be any restriction at all. Tony Mamo previously worked with AFR, designed new heads from scratch then eventually founded his own business. There he takes the AFR items and performs further wizardry, CNC'ing them and then manually porting the result. He also ports the FAST102 composite manifold: Before and after There's also an improved racing crank scraper and windage tray. Helps to keep oil in the pan. Supposedly gains 2% power. Tony also ports Melling oil pumps, so you get more oil pressure down low at idle, and the same as what you want up top thanks to a suitable relief spring. There's also the timing chain kit with a Torrington bearing to make sure the cam doesn't have any thrust. Yes I'll post a before and after when it all eventually goes together. It'll probably make 2kw more than a setup that would be $15,000 cheaper :p
    • Because the cars wheels are on blocks, you slide under the car.   Pretty much all the bolts you touched should have been put in, but not fully torque up.   Back them off a turn or two, and then tighten them up from under the car with the wheels sitting on the blocks holding car up in the air.
    • Yes. Imagine you have the car on the ground, and you mine away all the ground under and around it, except for the area directly under each individual wheel. That's exactly how it'd look, except the ground will be what ever you make the bit under each wheel from
    • Yes, if you set the "height" right so that it's basically where it would be when sitting on the wheel. It's actually exactly how I tighten bolts that need to be done that way. However....urethane bushes do NOT need to be done that way. The bush slides on both the inner and outer. It's only rubber bushes that are bonded to the outer that need to be clamped to the crush tube in the "home" position. And my car is so full of sphericals now that I have very few that I need to do properly and I sometimes forget and have to go back and fix it afterwards!
×
×
  • Create New...