Revving your engine

[modularv8]

Cruised through the UOA section this morning, analyzing the different viscosity grades for a given engine for the past 6 years. And several have posted racing/pegging the tachometer a few times (5000 rpms) and in every instance the UOA has shown significant wear (Fe, Cu, Pb, Al); especially bearing wear Cu/Pb.

I know this is common sense, but it didn't matter if they ran a 20 wt or a 50wt oil. Hard accelerations create high shear and pressures that lead to metal to metal contact, causing high wear.

 

[finalyzd]

When I did my uoa with PP I had two 120mph runs. And a lot of revving. Results came back great viscosity stayed within grade. Run was little less than 5k maybe from such a short interval it came out like that? All engines are different

 

[silverrat]

I must be really killing my oil then? I drive consistently in the 5-6000rpm range on my 22 km daily commute.

 

[Gary Allan]

Quote:
I know this is common sense, but it didn't matter if they ran a 20 wt or a 50wt oil. Hard accelerations create high shear and pressures that lead to metal to metal contact, causing high wear


This is not common to all who engage in racing either organized or Fast & Furious. Now you get some engine with 2-3x the normal output ..that's another story, but some raced production engine doesn't necessarily see that type of relationship between usage and wear indicators.

In the past we've seen tracked Corvettes that have pushed 290F+ oil temps show near totally normal UOA's using the OEM approved 5w30 M1. Something that would have me real nervous.

I would think that towing, at or beyond capacity, should simulate the same conditions. Yet all who do heavy towing do not see inordinate higher wear indicator rates. At least to some level of significance.

 

[Johnny]

Sure glad I did not do UOA's when I was a kid. Poor cars, I abused everyone of them.

 

[Gary Allan]

Agreed. Fast as you could in the space allotted.

 

[Johnny]

Yes sir, all with no seat belts, drum brakes, bias ply tires, and metal dash boards. How in the world did we survive?

 

[Craig in Canada]

Originally Posted By: modularv8
Cruised through the UOA section this morning, analyzing the different viscosity grades for a given engine for the past 6 years. And several have posted racing/pegging the tachometer a few times (5000 rpms) and in every instance the UOA has shown significant wear (Fe, Cu, Pb, Al); especially bearing wear Cu/Pb.

I know this is common sense, but it didn't matter if they ran a 20 wt or a 50wt oil. Hard accelerations create high shear and pressures that lead to metal to metal contact, causing high wear.


I drive a BMW with stick and I often hit or exceed 5000rpm in "regular" driving. Torque has fallen off somewhat by 6000rpm but I exceed that from time to time as well. My UOAs have all been great with M1 0W40 and GC, winter or summer. Remember it's stick, not auto, so "5000 rpm" doesn't equate to WOT. Oh, my car sees a decent amount of WOT too

I don't believe it's "common sense" that you're going to dump a load of wear metal into the oil just because you hit 5000rpm, which isn't even all that high.

The car is over 12 years old with ~180,000km on it and going strong.

 

[Nick R]

Hah, if high RPMs mean high wear, then my car will have horrible UOAs. With the lack of power and anemic transmission, it seems high rpms and redline more often than most cars do. But then again, with the tear down pics, there is still very clear and visible cross hatching visible on the cylinder walls, after almost 135,000 miles, so.....

 

[demarpaint]

Originally Posted By: Johnny
Yes sir, all with no seat belts, drum brakes, bias ply tires, and metal dash boards. How in the world did we survive?


+1!!!!!!!!!!!!!!!!!!!!

 

[1999nick]

Originally Posted By: silverrat
I must be really killing my oil then? I drive consistently in the 5-6000rpm range on my 22 km daily commute.


Wow! 6000 rpm must be 130 to 140 mph in either of your Hondas. Where did you say you live?

 

[Gary Allan]

He does it in 3rd gear.

 

[jazeo]

3 passes at the drag strip and the oil and filter gets changed, short blasts around town maybe every month. The best oil and filter (whatever you feel that is) just doesn't cost enough for me to think about it. Some may call that waste, I call it insurance...

No UOA's if it doesn't grenade I've got a good one, if it does I'll build another!

 

[Trav]

My first performance bike was 1000cc (60ci) and made 135 HP,
that would be the same as 350 ci engine making 787 HP.
It ran 8-10,000 RPM (12,500 red line) on a regular basis for extended autobahn periods,at 160,000 KM it still ran perfectly with zero drive train failures.Castrol 10w-60 from first OCI.
No high RPM until the oil temp gauge was in the green zone.

I suppose it depends on the engine design,quality of components and maintenance.The 100PSI high volume oiling system with 4 ltr capacity with large cooler didn't hurt either.

 

[mechtech2]

Originally Posted By: Gary Allan
Agreed. Fast as you could in the space allotted.


Looking back, this simple statement nailed the mindset of most guys.

 

[modularv8]

It just appeared to be that way from the UOAs. I'm glad to hear the contrary from others since I also peg the tach every once in a while. Like the acceleration of the V8.

 

[Mitch Alsup]

A couple of points:

A quick rev to the red line with the oil at normal operating temperatures probably does no harm whatsoever, especially compared to a few quick revs to the red line when the oil is above 285dF.

A few quick revs to the red line with the oil below 70dF probably does considerably more damage than a few quick revs to the red line with the oil at normal operating temps.

I would like to strongly imply that it is NOT the "few quick revs" that does the damage as much as it is "using the oil outside its normal operating range" that does the damage.

I would like to further imply that this holds true whether the red line is 5,000 RPMs or 15,000 RPMs.

 

[silverrat]

Originally Posted By: Gary Allan
He does it in 3rd gear.


Bingo, I do it in low gears.

 

[SpitfireS]

The higher the engine revs the higher the oil pressure generated by the journal bearings.. right?
High revs & thin oil!

 

[XS650]

Originally Posted By: Gary Allan
Quote:
I know this is common sense, but it didn't matter if they ran a 20 wt or a 50wt oil. Hard accelerations create high shear and pressures that lead to metal to metal contact, causing high wear


This is not common to all who engage in racing either organized or Fast & Furious. Now you get some engine with 2-3x the normal output ..that's another story, but some raced production engine doesn't necessarily see that type of relationship between usage and wear indicators.

In the past we've seen tracked Corvettes that have pushed 290F+ oil temps show near totally normal UOA's using the OEM approved 5w30 M1. Something that would have me real nervous.



He mention pegged tach at 5,000 rpm, he must have been referring to diesels.