TEOST or Noak...

[wemay]

A lower Noak vs a lower TEOST value. Is there now a consensus of which is more important concerning intake valve deposit formation?

Another question: Why isnt TEOST information as easily accessible as Noack?

 

[Nate1979]

I can't answer your question but I found these descriptions of the testing to be very interesting:
http://www.gf-5.com/the_story/testing/

 

[Quattro Pete]

For deposit formation, I'd say TEOST would be more useful as it actually measures the amount of deposits being formed during the test. Noack only tells you how much oil evaporates, but does not measure the amount of deposits left behind when this evaporation happens.

Ideally, you'd want both low Noack and low TEOST, of course.

It's also interesting that TEOST seems to be predominantly used in US specs (API/ILSAC). The Europeans seems to favor other high temp deposit tests.

 

[Quattro Pete]

Then again, TEOST MHT-4 is meant for measuring piston deposits. TEOST 33C is meant for turbochargers. Not sure how well (if at all) this translates into intake valve deposits.

 

[wemay]

The reason i ask is because im trying to choose between Castrol Edge EP 5w30 (best TEOST score in Amsoil test) and PPPP 10w30 with a 4.7% Noack, for next oc. Leaning towards Edge.

 

[Swift101]

Originally Posted By: wemay
The reason i ask is because im trying to choose between Castrol Edge EP 5w30 (best TEOST score in Amsoil test) and PPPP 10w30 with a 4.7% Noack, for next oc. Leaning towards Edge.


Blend them together 50/50

 

[CATERHAM]

The oils with the best TEOST scores are synthetic and have reasonably low Noack values but not the lowest. Some oils with very low Noack percentages have very high deposit levels.
IMO the lighter fractions of an oil that evaporate off do not contribute significantly to intake tract or piston deposit, it's the atomized oil itself in conjunction with the by-products of combustion that get past the rings into the crankcase and the oil that are the main contributor to intake tract deposits.

That said, some DI designs are more prone than others to the problem. I wouldn't be overly concerned about it unless you have an engine that reportedly has the problem and then I'd consider using an oil like Castrol Edge with it's very low deposit score.
I'd also keep the OCIs short on the assumption that clean oil will leave less deposits than dirty contaminated oil.

 

[wemay]

Originally Posted By: CATERHAM
That said, some DI designs are more prone than others to the problem. I wouldn't be overly concerned about it unless you have an engine that reportedly has the problem and then I'd consider using an oil like Castrol Edge with it's very low deposit score.
I'd also keep the OCIs short on the assumption that clean oil will leave less deposits than dirty contaminated oil.


The max OCI we can go is 5K miles. I wouldnt go any further. I was touting the conventional oil/3K mile oci horn for about one year here but finally succomb to going synthetic due to too many factors... Timing Chain/Turbo/D.I.

 

[Swift101]

Wemay, have you thought about using PUE 5w30? Perhaps the European formula is tougher and more shear resistant.

 

[wemay]

I will probably end up trying everything under the sun...lol. I've had my eye on the Edge (gold bttle) for quite some time. The TEOST results being the main reason. I just put it on hold since first trying to decide if conv/blnd/syn would be my avenue. Now that syn is it, Edge and PPPP 10/30 have pulled out front for the reasons given. Not that i would'nt try something else.

 

[Shannow]

Noack is specifically designed to represent the evaporation that occurs around the piston ring lands and cylinder walls...that's why it's 250C, and it's largely for emission control protection as the oil volitalised in this area has straight access to the catalyst.

see
http://www.bobistheoilguy.com/forums/ubb...e_a#Post3372187

Oil in the ring belt is there for approximately a minute, at a couple hundred degrees C...in the test engine, 0.41ml per minute makes it to the rig belt, 0.36ml/minute makes it back to the sump (per cylinder on the test engine, based on the Vauxhaul 2.0 geometry).

That's the purpose of the Noack test, to establish behaviour in this extreme environment...it's got nothing whatsoever to do with evaporation from the bulk oil in the sump into the PCV, in spite of the strawman argument that it does.

If TEOST has actual deposits measured, not losses, then it's a deposit test, and more applicable to deposits.

 

[Quattro Pete]

Originally Posted By: Swift101
Wemay, have you thought about using PUE 5w30? Perhaps the European formula is tougher and more shear resistant.

Do we actually know what its Noack is? Or TEOST?

The old TDS shows 11% Noack, but that doesn't even make sense if this oil is to meet MB 229.51 spec.

 

[wemay]

That's true, i thought to meet MB 229.51, it needs to be at 10% or below.