ayousef

well im trying to find a relation here, but im clueless and would like to save the trial and error for someone with more experience who can theoreticaly explain the correlation between oil grade/brand/viscosity and oil temp, and temp recovery on turbo'ed applications.

So what oil should I be using in the Dubai heat without overheating like crazy. I recently installed dual oil coolers instead of the fog lamps, but physically looking at the oil passage cores are very thin and would probably like the thinner oil and would allow for increased flow at the expense of less oil pressure etc...

Im currently using 20w-50 non synthetic (temp), but before I switch to another oil brand, im interested in knowing what should enable me to run the best oil temps, I also have some oil additives that "claim" to reduce oil temp, would have to try that out sometimes.

OUTLAWZ RACING

iTrader: (9)

The sythetics wil show a lower pressure due to less pressure to move it versus the non synthetic. As far as heat I would look for a oil with maxium heat coking resitance. Somthing around a heavy duty oil that tow trucks and big rigs use. Mobile one full synthetic works great, even that castrol edge works I run that **** in my honda that dosent tick any more lol. But I would want a high flowing oil in that heat to get to the turbos and the coolers. Less friction= lower oil temps I would look at mobile one and castrol edge, or Quaker state Q 4#4 suv blend.

VINCE

iTrader: (1)

I run Amsoil 5w-30.... My oil temps dropped going from 20w-50.

Inspector12

iTrader: (29)

Yeah Vince is seeing the same thing that I have been telling people about the thick oils and tight bearing clearances etc... It is not a good idea to run the heavy oils when you have most machine shops running a lot tighter clearances that what was the norm 20yrs ago. I wouldn't run anything thicker than a 10W40 I have been using the Mobilone 5W40 turbo desiel oil with great success in my S/C car and my turbo car. And I am not brand loyal really my friend from Royal Purple showed me the data and ever since I've been running either a 10W30 and now the 5W40. Also run the older versions of there synthetic oils as they haven't removed a lot of the additives and zinc from the oils like the government is making them do. Such as the Mobile One Extended Performance which is basicly there original formula. GL! That is all I can tell you and you can believe me or call some of the oil manufactures and ask these same questions and I am sure they will support most of what I have told you.
Jeff

ayousef

im going to switch to mobil 1 5w-30 which is the oil thats used stock for the C6 Z06's instead of this crap temporary nonsynthetic 20w-50, I know the thinner oil would work better with my cooler but should I have any hopes of seeing a "reasonable" difference, something id NOTICE at least or would I be wasting my time.

Ill see what happens to my oil pressure though.

ayousef

anyone else?

BigRich954RR

iTrader: (1)

I would do a mobil 10-40 or a Amsoil 10w-40. not sure how cold it gets there. IF it stays above 60 *F do a 15-40. All synthetic. DO Not put any additive to cool the oil down its all lies. could cause issues.

The brand and type of oil has very little to do with temp.

As long as your oil temp stay around 220 to 250 it wont matter cooler side use 30wt hotter side use thicker weight.

What oil pump are you running ?

ayousef

how about it never gets cold

however I dont think you are right about saying oil viscosity doesnt effect temp, it effects pressure and thus flow, and should in turn have an effect whether positive of negative on temps.

BigRich954RR

iTrader: (1)

It will have a affect on the temp but its so small doesnt matter much.

the lowing number has no meaning if you dont live in a cold place so id get a 15w which will help with thinning and shear of the oil. A 40 weight oil at 250* will flow like a 30 weight oil at 220 * so the weight changes with temp. THis is a rough number ill look up the right numbers in my book when i get to work .

Inspector12

iTrader: (29)

Thicker oil will be cooking as you try to force it though the clearances of todays machine work and cause the temps to rise and break the oil down faster, thus the thinner oil we are talking about will drop your temp and your presure will not change a lot, and oil presure is some what over stressed 20-40 at idle is fine and a general rule is @ 10lbs per 1000 RPM under WOT. GL! I am confident these recomendations will help the hot oil issues.

VINCE

iTrader: (1)

My oil pressure per my gauge did not change.

ayousef

Im putting this to the ultimate test, DUBAI SUMMER HEAT.

Just a few days away lol, ill report my findings.

Zombie

iTrader: (2)

I run 20-50 in summer when it's ridiculously hot 40-47 degrees and 15-40 in winter when it can get as cold as 0 degrees.

I've tried lower weight like 10-30 oils in summer and as the engine heats up the oil pressure plummets on my car. 30-40psi at 7000 rpms in summer with 10-30 vs 50-60psi on thicker weight oil.

BigRich954RR

iTrader: (1)

The oil will not be cooking because of it being a heavier weight. It wont break down more either. The only time a oil will break down faster is when its in a gear box and is being sheared and that will only break down the long chain polymers. which will make a 15-40 act like a 15 30 over time. and with enough time a 15wt.
So its still better to start off with a thicker oil to factor in it breaking down a little bit.

With every oil hotter it gets the thinner it gets. He starting off in a hot area with a higher hp car which makes the oil run hotter. the first number is the oil cold pour point. Which doesnt matter here cause it wont be getting that cold to matter. Wider the spread 0w-40 vs 15w40 the more long chain polymers are added to make the oil work in different temps ranges, but the easier they break down.

Now im pretty sure hes pushing a good amount of hp cause im running the same engine with 15 psi to. Now there alot of psi in the cylinder all that pressure is pushing down on the connecting rod to the bearings on the crank. Thinner oil gets pushed out of that area faster and has a greater chance of metal to metal happening. So to start off with a thinner oil with hotter oil temps is just a bad comb= make even thinner oil when at temp.

Whats the oil temp any ways i dont remember what people are thinking to hot is ?

This is what i got from team honda when i was asking around 5 years ago
(The oils of well known firms...are so far advanced today that even at a temperature up to 320 the oil film in the bores does not break down and you can still consider the lubricating ability to be sufficient... The maximum oil temperature that our motors can be expected to sustain without serious damage is 280).

This is for my 14k rpm Race bike it made close 185 RWHP. I know its not a ls motor but I ran this thing in the 280 range alot and a few times into 300 hell the headers would glow bight red at the end of a long straight. Never had a oil issue and ran a 15w 40wt

crashly

i would be MORE interested in the clearances of the engine, when it was assembled....
THEN make a desision on the weight of oil to be used, with the hp of engine to be added to the answer of the oil vis answer...


also,
is the oil cooler a full flow, or bypass type ???

Inspector12

iTrader: (29)

Cooking is an analogy cause I am not an oil expert nor do I know all the terms they use in the industry when talking about API rateings bla bla bla etc... And I understand exactly what you are saying about oil getting thinner as it gets hotter, but there is a breaking point for that and I am in Texas so we don't have much of a winter hear although we don't get as hot as him either, well unless you factor in out outragous humidity lol. And the first number the one you say is the cold pour does affect how fast a car gets lubrication to all the parts during cold start up where, and is where most cars get most of there wear, although I wouldn't know how it affects it breaking down with a chain of polymers as that is over my head and never cared to get that technical with it. All of my info is from what I was shown to me by a friend that works for Royal Purple and well trial and error from my own cars. And as far as it breaking down I am speaking of more heat will cause oil to break down faster.

MY99TAWS6

iTrader: (3)

I am thinking since drive car from about april 1 to nov 1 here and it gets a bit cooler at the end or beginning of the driving season that should run maybe 10/40 synth or possibly 20/50 synth.
Currently in my 91 race talon with stock engine just running amsoil 10/30 they had no 10/40 in town and figured since it was stock motor with stock clearances 10/30 is fine for now. The 408 in the 99TT figured bigger clearances and still running the lower pressure slp spring so thought 10/40 or 20/50 synth would be fine for that. But also worried a bit that the heavier oil might not go thru the turbo oil feed lines as well especially when colder out.
Running non synth 10/40 just until end of season in the 99TT. Was going to run 20/50 non syth but dont think will. Non syth really doesn't flow well when cold even with numbers like 10/30 or 5/30. Just go put out some non synth oil and test that theory sitting in the container.

ayousef

Guys, my engine builder doesnt mind me using 20w-50 or 5w-30 as long as engine temp and pressure stay intact, now my problem is the follows:

I dont really freak out when oil temps go high, but the coolant temps are the ones that seem to freak out and get pulled upwards with the oil temp no matter what i do. Now on a speed density (ONLY) vehicle, you're getting into a range where the ECU is pulling a good deal of timing on a vehicle that already runs low timing, so imagine pulling 7-8 degrees of timing and the consequences of AFR changes. I cycled through a few plugs because my car was tuned at the 90-100 degrees CELCIUS water temp range, but because of the oil issue, water temps go as high as 110+ under normal cruise, pull timing, ends richening up the mixture so much, the plugs literally die...

Now what I did was put it a set of oil coolers and trashed the front fog lamps, mounted them in an engine >> cooler1 >> cooler2 >> engine config, although I should have thought of doing two seperate engine >> cooler 1 >> engine AND engine >> cooler 2 >> engine but for the time being whatever.

Yes temps were better definitely, but on a highway cruise at night with the ambient temps at about 37 degrees Celcius, the oil temp didnt stop climbing "Slowly" - instead of dropping or hanging in there. The oil used was some trashy temporary non synthetic 20w-50, and im wondering if shifting to mobil1 super synthetic 5w-40 would help, any lower and id suffer low oil pressure issues I GUESS.

The other problem is the my plate and fin oil cooler features very narrow plate openings and my educated guess is it will respond better to a quicker flowing oil as opposed to oil that would have to cook itself through etc...

Zombie

iTrader: (2)

ayousef, what compression is your engine and what kind of timing are you running in vacuum? If the timing is too low in the vacuum area it will cause the engine to produce excessive heat. Most people don't notice it, but in hot climates it's more sensitive. BTW, what are the highest temps where you live? I'd imagine it's similar to Las Vegas unless you guys have the humidity too.

I have trouble keeping my water temp down with the a/c on when it gets over 40C here in vegas. My water temps will go 115C.

ompong

50 is too tick means creating more friction therefore creating more heat. try using lower grade people here in dubai usually using 40 but if your car is not so old you could use the 30. the __W is not so importand because we are not going less that 0 here. i would suggest liquio molly 5W30 fully synthetic thats stable in any temperature.