Forged Engine - Which Oil?

[androo007]

Hi Guys,

I did have a search but couldnt find the answer I need.

What oil do you guys that have a forged block run? I'm just finishing up on running in miles and need to switch over to fully synthetic.

I think Pete recommended 10w/40, but the guy tuning the engine said 10w/60 (which seems a little thick?)

Interested to see what you guys puffing out 350-400hp are using.

thanks!

[ashley]

The answer depends on how hot you plan to operate the engine at, if you are expecting 120c+ oil temps consistently then 10-60 would make sense.

If you are expecting peak oil temps of up to 120c, but normal operation 90 - 110c, then 10-40 is probably a better bet (in my understanding anyway).

FWIW I'm on Millers CFS 10-40

[androo007]

Im not looking at oil temps

no track use, weekend car good old fun car but no long periods of sustained boost etc I'd imagine 10w/40? Is that what Pete recommends? I can't remember.

You're a car boff so I'd agree with you

[Martin F]

I asked the same question to opie oils, Fuchs Titan Race Pro S was the recommendation, 10w 60w IIRC but I cas check what's in the shed later to confirm

[ashley]

Hi Guys

Would appreciate your view on engine oil for my new engine please.

Toyota 2.2l turbo charged engine
5S block
3SGTE head
High lift cams
Remote oil filter (using the Toyota Camry v6 oil filters)
Oil cooling will be plumbed in if required
Forged CP pistons/ Carillo rods
Morosso baffled sump
HTA3579r turbo

Prior oil temps were peaking at 102c (with oil cooling, this has now been removed), target peak oil temps now 110 - 120c (all measured at the sump)

Water temps typically stable at ~90c

Target power up to 600hp (max rpm 8k)

Car use: fast road and track

Prior oil used: Millers CFS 10w60 Nanodrive

I suspect the 10w60 is too thick for the temperatures I am seeing, so was proposing going to a 10w40 instead (same brand).


Also- I have a standard Toyota MR2 1995 gearbox, with increased final drive ratio and a Quaiffe ATB. I was planning to continue using Millers CRX 75w90 NT in it.


Does this all sound sensible, and what (if different) would you recommend please?

Thanks

Hi Ashley

With the oil getting to 120C, a quality 10w-40 is ideal and the Millers CFS 10w-40 is one of the very best.

http://www.opieoils.co.uk/p-60217-mille ... e-oil.aspx

The CRX NT 75w-90 is ideal for the box with a Quaife.

http://www.opieoils.co.uk/p-60230-mille ... n-oil.aspx

Regards

Tim

Cool- so basically go with my current plan then.

What is your view on the Miller's Nano Drive? I'm surprised not to see it available in 10w40

http://www.opieoils.co.uk/p-73733-mille ... e-oil.aspx

Thanks for the advice

Hi Ashley

Nanodrive oils are very good, we're getting very good customer feedback from them. The CFS NT 5w-40 would probably be fine for your car, but a 10w-40 is a bit more stable and with the sort of build that you have, you might find the 5w-40 would burn off a little quicker.

Regards

Tim

[androo007]

Only question i'd have then Ashley, is do you think with your setup, the oil is cooler than a convential 3S setup?

would 60 be more beneficial for me? I'm never sure on this.

[kirk]

Taking this slightly off topic, sorry!, I also run Millers CFS 10w40s but on day to day I rarely see 90c (usually around 85c) The only time I see that is when I spank it a bit. Now I don't know whether that's down to the placement of the sensor or not but I do find it a bit odd.

[ashley]

I'm measuring oil temps in the sump, which is a larger than stock sump. The remote oil filter does give some cooling for sure, and I have no stock oil cooler fitted at all.

That said- when I was on a 3S block with no oil cooler, oil temps very rarely got above 105 - 110c...although I wasn't racing it/ on track.

[ashley]

Only question i'd have then Ashley, is do you think with your setup, the oil is cooler than a convential 3S setup?

would 60 be more beneficial for me? I'm never sure on this.

I would go with 10-40 mate, honestly- unless you are absolutely spanking it I can't see you ever getting the whole oil system over 120c...and if you do, then I'd be looking at a remote oil filter for cooling purposes, not thicker oil

[androo007]

Perfect, thanks Ashley.

Really excited to get it mapped at last!

[gnzyza]

As Ash said 10-40 is Ok going on oil temp range.

It gets to 110 when driving relatively hard and 120 when really gunning it.

[C35Rob]

my oil temps (measured from sandwich plate with a Greddy Gauge) usually sits at 95-100 degrees when cruising, up to about 110 degrees when pressing on and I have the warning on the gauge set to 115 degrees, which I've hit a few times when really going for it. I use 5-40 Fuchs Titan pro race S oil which is a quality ester synthetic oil

Oil pressure (measured at sandwich plate) is are 2 bar hot idle, obviously rising with revs.

I'm certain a quality 5/40 or 10/40 would be what you need, but the best idea is to go with what the engine builder recommended.

[Race Idiot]

I was seeing max temps of around 130 at Bedford Autodrome after about 6 laps. Other tracks it's hovering around the 125 mark.

This is with a weenie little TD05-16g at about 13psi on a rather high miles unopened rev3 motor.

I run whatever 10-60 oil and change it fairly regularly, I'd probably go with a 40 grade if I wasn't using the car on track. The new motor will have an external oil cooler so I can run for longer on track without hitting those high temps.

[Gullzter]

I use 10w60 nano drive on my build as recommended by the builders and tuners of the car and I've never seen temps above 110..
Normal temps sit around 80-90.

Would be good to find out more about it as I'm going to do another oil change in next couple of weeks.
There doesn't seem to be a consistent answer to this and who do you listen to.. Oil experts or engine build experts?

[ashley]

Yep- I'll be honest, the only reason I was using 10-60 was because Rogue suggested it...but I think that was on the assumption that I was racing the car....which I'm not. That's why I checked with the guys at Opie before changing to 10-40.

You could always ask Tony for his advice, he did build it after all...

[C35Rob]

Go with the engine builder, only he knows what he specced the bearing oil clearances at, if he's gone a bit slack (as many big power engine builders do) then he will probably want you to use a thicker oil. With stock bearing clearances on a street engine then there's no need for a 10/60

[gnzyza]

So with stock oil clearances, would 10-40 still be used on track? Or better to go thicker.

[ashley]

With stock clearances it all depends on what oil temperatures you are seeing

[C35Rob]

With stock clearances you will find that oil will heat up quicker on track as tighter clearances mean greater shear stress on the oil (oil doesn't simply 'slide' on bearings, there is a boundary layer on both the shell and the journal which are stationary and the oil has to shear as the journal rotates and rides on the oil wedge) which in turn means greater heat, this obviously is greater with more viscous fluids. you want to run the thinnest oil possible while still maintaining oil pressure.

There's a reason that modern engines use tight clearances and water-thin oils, and that's primarily to reduce friction and pumping losses in the motor that reduce power, simply dumping in 10/60 cause your oil gets hot isn't the right way to do things because it's thicker across the whole temperature range than a 5/40 or 10/40 would be.

A much better approach would be to use an external thermostatic oil cooler to keep your oil temp in the ideal range. Especially on something that sees street use.

This is a good post from "the oil guy" @ opie oils, which pretty much tells you what you need to know

Let's get one thing clear, I supply 10w-60 and recommend it where it is appropriate for the engine or the application but conversly I caution against it's misuse!

I have debated this many times on many car forums and I know there are some that do not agree with me however I have never had a reasonable technical explanation why 10w-60 is in fact suitable, it's certainly not mentioned in the handbooks of many modern highly tuned performance cars, with the exception of some Alfa Romeos for "spirited driving" whatever that is meant supposed mean.

Explaining this is diffucult so there may be questions but I'll try my best to explain it in plain English!

Lets look at what oil specs actually mean and particularly the higher number which is in fact the oils SAE number (the "w" number is in fact the cold crank viscosity and measured in a different way) The SAE number is measured by the oils viscosity at 100degC.

Your cars require according to the manufacturers specs, sae 30, 40 and in some cases sae 50.

To attain the relevent sae number the oil has to be at 100degC (no thinner than)

SAE 30 11cst approx
SAE 40 14cst approx
SAE 50 18cst approx

Centistokes (cst) is the measure of a fluid's resistance to flow (viscosity). It is calculated in terms of the time required for a standard quantity of fluid at a certain temperature to flow through a standard orifice. The higher the value, the more viscous the fluid.

As viscosity varies with temperature, the value is meaningless unless accompanied by the temperature at which it is measured. In the case of oils, viscosity is generally reported in centistokes (cst) and usually measured at 40degC and 100degC.

SAE 60 is in fact 24cst viscosity at 100degC!

This is 33% thicker than an sae 50, 70% thicker than an sae 40 and over 100% thicker than an sae 30!

So, what's the problem with this thickness?

Well, this is measured at 100degC and at lower temps (70-90degC) all oils are thicker than at 100degC so the problem is compounded to some extent.

The downsides of such a thick oil (when not specified) are as follows:

Additional friction, heat and wear.
A reduction of BHP at the wheels
Lower fuel consumption

The thicker the oil is the more friction and drag and the more power the engine needs to move it around the engine which inevitably translates to less at the wheels.

So, when do we spec a thicker oil?

Well, you will probably have seen us on occassions recommending a 10w-50 but only in these circumstances.

1. If the car is heavily modded and heat/oil temperatures are excessive.
2. If the car is used on track and heat/oil temperatures are excessive.
3. If it's required by the handbook.

Our criteria for this is based on oil temps as an sae 40 semi-synthetic can handle around 110degC for limited periods whereas a proper synthetic sae 40 can hande 120-130degC for prolonged periods due to its thermal stability.

Once you see more than say 120degC for prolonged periods an sae 50 is adviseable as it is 18cst at 100degC and still 11cst at 130degC! This is in fact the same as an sae 30 at 100degC.

More importantly at 90degC an sae 40 is 15cst, an sae 50 is 20cst and an sae 60 is 30cst!

In a worst case scenario with thick oils (when not required) is that you will experience air entrainment and cavitation inside the bearings at high RPM. Not clever stuff!

I know this is technical stuff but oil is a combination of science and engineering and few people know enough about it to make an informed choice. Just because your mates use it and have had no problems is not a good enough reason to use it, your engine would prefer and benefit from the correct oil.

Cheers
Simon

[androo007]

What a reply! Thanks Rob.

10w-40 fully for me it is then