Bore scoring - do all engines have it to some extent?
#31
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=
#32
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=
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=
#33
Various oils
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=
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=
#34
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.
Cold thickness is irrelevant as bore scoring occurs on a warm engine, not a cold one.
#35
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=
#36
Rennlist Member
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
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
#37
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=
Agree with oil and oil starvation.
Cheers,
=L=
#38
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?
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?
#39
Drifting
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.
#40
More on Millers NT oils
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=
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=
#41
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?
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?
The following users liked this post:
jlert (11-03-2022)
#42
Race Director
Does anyone know how the p-dealer would determine that a cylinder is scored? Wouldn't they use a bore scope? And what do they look for(criteria?) to determine that the cylinder is scored or scored enough to warrant an engine replacement. Cylinder scoring does seem to occur... I considered purchasing an '06 C2S two years ago which had it's engine replaced under warranty due to scoring. Decided instead to purchase an '08 C2S with original warranty and CPO. I don't believe that my engine has any scoring. No smoke coming out the tailpipe nor any signs of oil consumption... but I'd like to baseline the images of my cylinders and compare as time goes by. Not to mention that if I find something wrong then I'd ask the p-dealer to address it before my CPO runs out next year.
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.
#43
Rennlist Member
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.
The following users liked this post:
jlert (11-03-2022)
#44
Drifting
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.
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.
#45