Luxter

Most welcome. Happy to contribute.

Please let us know the impressions with CFS 10W-50. Temperatures and pressures in particular as compared to your previous oil selection (M1 0W-40, I assume).

I will have an UOA posted later this year, curious to see yours as well if possible.

Track use, I am assuming you will be using 10W-50 grade, right?
The PRO had a PDF of UOA's taken along several hours of racing in 996 engine and apparently the 5W-40 did not shear out of grade or otherwise degrade much beyond its initial properties.
Happy motoring!

=L=

Gibbo

Yes 10W-50 for sure when at track, even though 5W-40 probably be fine, the 10W-50 does offer some extra protection.

Luxter

I spent some time on Mr. Widman's web site plotting some oils (many thanks BTW):

http://www.widman.biz/English/Calculators/Graph.html

Here is a table that lists Mobil 5W-50, 0W-40 and Millers CFS 5W-40 and 10W-50 both NT up to 125*C = 257*F which seems to be fairly common oil temperature during racing and in hotter climates.

Here are the results:



I will let others interpret the numbers.
My daily driving typically gets me into about 95-100*C oil temp. range.
Cheers,
=L=

Gibbo

The CFS remains much thicker at high temperatures affording much higher levels of protection, equalling better cooling, less scoring.

Cold thickness is irrelevant as bore scoring occurs on a warm engine, not a cold one.

Luxter

To further clarify my previous statement on this subject, LN sells Whaler T-stat and Hartech offers AutoRad product.

Both, according to Baz Hart are equally good products.
Here is what Baz states in another forum:

"I have tested both types and they are slightly different in response times/damping but I don't think it makes any difference - either should be a great improvement.

Baz"

Cheers,
=L=

utkinpol

I run now on 5w50 mobil1 oil and it holds up fine all seasons long, summer and winter. there are also no issues to run 15w50 oil in the summer, as soon as temp goes above 50deg. in the winter 15w oil is too heavy and too thick for tiny passages that are not designed for this oil.

if you are in south states and track car in close to 100deg ambient temp then use 15w50 for sure.

with 3rd radiator in place low temp thermostat is not really needed. what you need, in case of a M96/M97 engine is this oil pan -
http://www.suncoastparts.com/product//FVD20798801.html

I think it is only one available now, cheaper one from 996 x51 kit is no longer there.

deep sump spacer kits do not prevent core issue of oil starvation as oil still get pushes aside in a sweeper, but, you can do either spacers or this pan. with spacers this pan will not work as it has to have its rubber baffles to fit tight against engine walls to prevent oil from spilling away from pickup tube

Luxter

That is not quite what Hartech recommends for daily driving. They (Baz) state exactly opposite with substantial explanations why on Pistonheads forums. Again, DD rather than racing.
Agree with oil and oil starvation.
Cheers,
=L=

BED997

I haven't read through all the replies, but are some of the symptoms of bore scoring typically consistent oil consumption, black smoke at startup or sooty tailpipes?

I'm not saying all cars doing these things have scoring but does a car with scoring issues exhibit identifiable signs of a problem - or does the engine just fail?

USMC_DS1

Smoke coming out of both sets of pipes may be a failing AOS. Smoke coming out of just the driver side pipes may be related to scored cylinders on bank 2(passenger) side.

Luxter

Hey Guys,
For those who are interested in Millers NT lubricants, here is an interesting discussion on BITOG:

http://www.bobistheoilguy.com/forums...99173&page=all

67 King also contributes to RL.

Cheers,
=L=

7500rpm

As USMC_DS1 said, my friend's driver side tailpipe accumulates black soot. I have since identified with a bore scope that his #6 cylinder has scored bores. Other symptoms, like you said , are heavier oil consumption, puff of smoke at start up, clicking engine noise and unhappy owner. He still drives the car around, though and the engine hasn't failed.

Macster

Based on my talks with various techs the general SOP is as long as the engine is not exhibiting any abnormal behavior, the CEL is off and any other info obtained from the car's DME doesn't show any issues, there is no problem.

Like I posted before while one can view the cylinder with a scope he can't measure the depth of the "score" marks nor make any judgement call as to the condition of or the integrity of the cylinder/rings/piston interface.

So, one has an engine with a suspected "scored bore". No continuous smoking. No CEL. No rough idle. No misfires. No other signs of any real issue. No problem.

If the engine is exhibiting any issues, serious issues, then the engine is replaced (if under warranty) with no real determination of what the problem is.

While this seems perhaps odd it makes sense. The engine gets shipped back to Porsche which can do an in-depth analysis of the engine and its failure and learn something from this.

What it probably learns most often, has reinforced, is occasionally an engine fails either from an assembly problem or a defective part. This is why there is a new car warranty.

utkinpol

lowering primary temp level with thermostat affects engine more as it gets to run overall cooler then it`s designed for and it affects it negatively.
proper way to affect 6th cylinder cooling is to drop down the motor, increase openings in the gasket and do other alterations good shops do to racing motors to optimize coolant flow.

simplest advice for drivers is to install 3rd radiator and drive car close to 3k rpm to have decent rate of coolant flow and cylinder should not be overheated much in such situation. for those who do drive a lot in traffic and spend a lot of time on idle not moving much - best solution is to move to DFI 997.2 engine and skip all that useless battle.

USMC_DS1

+1, I spoke to my SA a few wks ago re this... this is his assessment as well. It takes a lot of symptoms before Porsche would warrant any work on the engine. BTW, my p-dealer(only one in Austin) has never seen a scored engine. May be due to the smaller market/number of 997's here in Austin. Next time I replace my plugs I'll capture a few pics just as a reference. May try to run a probe of some type along the cylinder liners to get a feel of the depth of any score like marks if I see any. Cylinder 5 and 6 are the primary suspects... the real challenge will be catching the cylinders when they're in the proper position to allow me to inspect #5 & #6 w/o having to turn the engine.

7500rpm

Why don't you want to turn the engine? A couple of revolutions wouldn't harm anything, would it?