BillK, I've got a question for you about oil changes. The training session I was in today was about engines and new generation OBD and one of the things we talked about was oil changes and the Instructor said was not to change the oil in a new or rebuilt engine for 5000 miles, personally, I think he is wrong, but I would like to get the facts from someone like you. Thanks for your time.

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Leo Paugh
Maryland Chevelle Club #017
The bitterness of poor quality remains long after the sweetness of the low price is forgotten.

MarylandChevelleClub (http://www.clark.net/pub/chevelle/mcc.htm)

I'm not Bill, or even much like him http://www.chevelles.com/forum/smile.gif, I guess, but I'd change oil shortly after any rebuild. There are lots of "things" left in an engine after rebuilding, or new manufacture for that matter. Even if the builder assured me 25 hours was spent cleaning everything and the engine was built in a NASA clean room, I'd still change the oil. In fact, I'd do the first oil change right after cam break in.

What was the logic behind his statement?

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Pat Kelley
66 El Camino, daily driver
67 El Camino, STRIP/street
Pat's Page (CR Calculator, Utilites) (http://cochise.uia.net/pkelley/)

[This message has been edited by Pat Kelley (edited 08-27-2000).]

His logic is that with todays low friction rings, that "stuff" in the oil helps to seat the rings better. As I said, I think he is wrong and I would want to get that stuff out of my oil as soon as the engine had run for a while at operating temp.

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Leo Paugh
Maryland Chevelle Club #017
The bitterness of poor quality remains long after the sweetness of the low price is forgotten.

MarylandChevelleClub (http://www.clark.net/pub/chevelle/mcc.htm)

Personally I think an early oil change on a new engine is a very good idea simply because any hidden junk will be flushed out, plus a lot of metal gets shed from parts during the initial wearing in. I suppose an exception to the early oil change theory would be due to the use of a special high zinc content break-in oil being used. The zinc in break-in oil acts as an additional barrier during the first few miles of high initial wear. Your hardly hear about the 'stuff' nowadays, and it is expensive. Perhaps that is the 'stuff' that your instructor is talking about, and if so does have some merit. Still I'd flush it out after 500 miles of specific ring seating, although a change after the initial cam break sounds intelligent.
As an aside, there is such a thing as oil analysis. It was developed by necessity for marine use. You don't simply change a 1000 quart sump on a ship just because it's "a good idea to change the oil". An oil sample is run through a spectrum analyser to detect all manner of heavy metals, antifreeze, combustion by-products, water etc.

Yep, the Air Force used to call it a SOAP sample (No,not "Ivory"). Spectroscopic Oil Anaylisis Program. Take a sample shortly afetr engine shutdown and have it spectroscopically analyzed for evidence of excess wear as indicated by elevated levels of silver, copper, manganese, tin, etc. You can have it done for your car engine too if you you have the $$$ to spend on stuff like that.

We used to do the oil sample routine where I work, but it was at the same time as the oil change and we finally got the supervisor to listen to us that it was a waste of money to do an oil change and take a sample at the same time as they always said to change the oil at regular intervals. We did get the analysis, although it was after the oil change.

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Leo Paugh
Maryland Chevelle Club #017
The bitterness of poor quality remains long after the sweetness of the low price is forgotten.

MarylandChevelleClub (http://www.clark.net/pub/chevelle/mcc.htm)