Dirty Howie

Will oil analysis or something else short of opening the engine alert you to initial bearing wear ?????


DH

allanlaw

My recollection from some prior post is that something in the oil will show an increase if the bearing is on its way out - although of course I can't remember the details . . .

ronsc1985

Probably but it really doesn't tell you how much. What you are interested in is whether you got through the babbitt, and the underlaying metal and into the bearing shell. Once you get into the copper underlay (or whatever the soft metal being used), it's really obvious in a cut open oil filter. It kind of looks like you just hit the mother lode when panning for flake gold.

The only caution when cutting apart oil filters is you have to cut them with something that in itself doesn't make metal flakes. A lot of people use cartridge oil filter, like a Canton, so they can unbolt the cannister and get a look at what the filter is trapping.

yanniz

System 1 is what I use for most of my cars....

This is a really good web site with very informative information...

http://www.bobistheoilguy.com/

allanlaw

Here's what they say:

"Some of the metals tested for and usually included in analysis of an oil sample and their potential sources are:



* Aluminum (Al): Thrust washers, bearings and pistons are made of this metal. High readings can be from piston skirt scuffing, excessive ring groove wear, broken thrust washers, etc.
* Boron, Magnesium, Calcium, Barium, Phosphorous, and Zinc: These metals are normally from the lubricating oil additive package. They involve detergents, dispersants, extreme-pressure additives, etc.
* Chromium (CR): Normally associated with piston rings. High levels can be caused by dirt coming through the air intake or broken rings.
* Copper (CU), Tin: These metals are normally from bearings or bushings and valve guides. Oil coolers also can contribute to copper readings along with some oil additives. In a new engine these results will normally be high during break-in, but will decline in a few hundred hours.
* Iron (Fe): This can come from many places in the engine such as liners, camshafts, crankshaft, valve train, timing gears, etc.
* Lead (Pb): Use of regular gasoline will cause very high test results. Also associated with bearing wear, but fuel source (leaded gasoline) and sampling contamination (use of galvanized containers for sampling) are critical in interpreting this metal.
* Silicon (Si): High readings generally indicate dirt or fine sand contamination from a leaking air intake system. This would act as an abrasive, causing excessive wear. Silicon is also used as a anti-foam agent in some oils.
* Sodium (Na): High readings of this metal normally are associated with a coolant leak, but can be from an oil additive package."

Painrace

I can't tell you the number of cars I have raced or the number of engines I have blown up. I can tell you road race engines will not live at 6,000-7,000 RPM with 20 psi oil pressure. GM says the LS7 does not need 10 psi for every 1,000 RPM. I have to believe them but I can tell you from many, many experiences that 20 psi will never do it at any temperature at high rpm. I believe there is simply not a thick enough layer of oil at high temperatures and low psi for the bearings to live. If you don't believe me, try it!

Jim

Painrace

We use 15W50 or straight 50W and have very large oil coolers and radiators. Our engines run for hours not seconds or minutes. I don't think we are comparing apples to apples.

Jim

'06 Quicksilver Z06

Jim, you mentioned 15W50 in another posts in response to a question I asked.

Would you recommend it for a typical track day in our cars?

Thanks.

THXBRETT

100% agree. The stats on this thread are skewed to say the least. It seems from polls that there are approx 130 members on here with the LS7. 8 Have failed that were "stock". That is 6.15%. So does that mean that there are 1560+ blown motors out there? Probably not. But it is possible based on this whacked way of collecting data! How many more motors have failed on this forum with coil overs, better rubber than the runcraps, an intake or cat back exhaust? 10 more? 20 more? Does that mean we are at 30 failures out of 130, or 23% of LS7owners then? $80K should not get you a blown motor. Period. One motor letting go is unacceptable. 8 on this forum alone is retarded, let alone many more that have simple upgrades, such as tires for crying out loud. Pathetic to try and excuse this issue with nonsense stats like only 8 out of 25,000 have failed....

jimman

Curious, if it's nonsense you must know the real number so what is it?

Joe_Planet

Even if the engine blows GM will replace it under warranty... I dont see what the problem is...

Painrace

Absolutely and so does Katech, LG, MTI and anyone who has ever raced or built competition engines. I know a few guys that fell for the line that 0W30 will give them a few more HP! That may be trure for drag racing but you need the 50W when you get oil temps to 260-280 degrees. I use 5W30 on the street because you never get the oil hot. If you do a cop will be close by.

My recomendation is Mobil or AMSOIL 15W50.

Jim

Dreamin

Don't feed the trolls

ronsc1985

It's not apples to apples but the loads on drag race engines far exceed anything you ever have in any road race engine which is kind of evident since the drag motors don't last all that long even with the best parts (maybe 24-35 minutes total under full power, 200-300 passes, before rebuilds in my case).

The issue isn't if you can get by with 20 psi for a long time but rather if a 100 millisecond or so infrequent pressure drop to 20 psi will kill the motor. In my case it didn't and the oil temperature was always
220 + since we preheated the oil mostly to ensure the water and unburnt alcohol in the oil vaporized and was sucked out by the crankcase evac system.

I don't see any reason why if 20 psi spikes are a problem why a 2 qt or so Accusump plumbed into the main oil gallery, which you can easily access (I think that is where the oil pressure sensor is located), wouldn't cover these short periods. They come with solenoid valves if desired so you can choose when to have it operate. If I remember correctly they will always fill but won't discharge unless you have the solenoid activated. This among other things keeps the can filled when you shut off the motor if you use the ignition switch as the solenoid power source.

jimman

In your opinion is there a difference in effect between a sump and the sandard type of oil system in regard to oil pressure. The reason I ask is that the Z06 was the first Corvette I've owned that came from factory with oil pressures higher than 50psi. That being said I never had any issues past or present.

Painrace

You said it! Your engines are far more powerful but don't last as long. You get a lot more out of them. do not disagree for short spirts that a down spick to 20-25 psi at 220 degrees may not hurt a engine that is only going to last 25-30 minutes. Road race engines last 15 hours tops as full load. 25 hour race engines are detuned so they will live. I believe it is apples to oranges. Just my opinion.

Jim

Painrace

Oil pressure is usually set by the manufacturer. A true dry sump pump has a pressure adjustment on it. Either system will work on the street. When you start doing road racing a proper dry sump system will always supply the oil needed at the right amount of pressure all the time. Wet sump engines can get the oil sloshed away from the oil pickup with high side or braking G-Force loads and the bearings get smeared which eventually causes failure. I prefer dry sump but most of the time on the highway it does not matter. I think the C6Z is an outstanding performance car that is well engineered.

Jim

jimman

Seems like we should be experiencing more problems with all the others instead of the C6 Z. I wonder is the oil level more critical with the dry system.

Painrace

Oil level is not critical in the tank except at high RPM with high G-Forces. The LS7 has a large oil pan that can hold a lot of oil. The valve covers also have a vacuum on them so oil can be held in the heads a bit. This reduces oil in the dry sump tank so there is less time for the tank to get the air out of the oil. The ARE solution is a smaller oil pan, and additional scavage pump to get the oil and more oil back to the tank quicker and a larget dry sump tank. ARE also supplies a breather tank that allows filtered air into the valve covers and intake. Katech adds their upgraded oil pump with more scavage capacity and you are getting close to a true dry sump system. The C6R has a scavage pump with four (4) pickups mounted with a very shallow oil pan so almost no oil stays in the pan.

Adding too oil to the stock system could cause oil to be sucked into the throttle body whick is not good.

Jim

dbhajek

I dont understand how you can call the oil system in the 06-08 ZO6 outstanding and well engineered when an advance driver, no mater how small of a percentage of drivers that is out there, and no mater how rare of a condition it could be, can push the oils system over its limits with the car in stock form. The oil system has zero room for error in stock form, with a above average driver.

To me if Ron Fellows could jump in a 06-08 ZO6, that is all stock, and run it 100% at any track without getting any oil starvation then I would call it outstanding and well engineered. I am talking HPDE, not racing.

I know I dont have a 5th of the kowledge of race cars or race driving that you have but I dont think you have to come up with the conclusion that the oil system in the 06-08 ZO6 isnt outstanding.

Unless you are just talking about street. Then I would agree the Z06 is outstanding and even over engineered for the street.