cv67

After reading my 1473rd oil debate and people claiming GM used Mobil 1 in a lot of Vettes and Zs from the get go...

When they are initially assembled, run in, checked for emissions before they leave the factory are they running a cheap dino oil and then switching to Mobil? Seems like it would be a waste.....

What is initially put in these cars.
I want to run my new motor in with Mobil 1 from the get go, dont buy this "rings willnever seat stuff" with the fine hone finishes and tight clearances we have today. IMO some friction period will seat them...

Anyone know, opinions?

glass slipper

The 405 HP engines were "run-in" with Mobil 1, you are correct in thinking it doesn't matter to ring seating/break-in. What rings did you use in your new engine? If you used moly rings, the ring material is either cast iron or steel but the face of the ring that rides on the cylinder wall has a "moly" (molybdenum) coating sprayed on or imbedded into the face of the ring. The moly coating is porous (holds oil) and relatively soft compared to the cylinder wall, therefore it will "conform"/break-in to the cylinder wall easily and quickly. Here's a link with very in depth analysis of different ring materials, advantages/disadvantages, and lubrication:
http://www.vtt.fi/inf/pdf/tiedotteet/2002/T2178.pdf
It's a long read that talks a lot about diesel engines but there's a lot that applies to gas engines too...you might want to save reading it for when you have 30 minutes to devote to it.
Moly rings (used by US manufacturers) have easy break-in and the chrome faced/plated/steel rings (used by most Japanese manufacturers) have difficult break-in. The "chrome" rings are very hard requiring a rough surface finish and a break-in interval to seat the rings. This break-in interval consists of the accelerate/decelerate cycles you keep seeing in different threads but is simply not needed for engines with moly rings as the break-in is almost instantaneous. Here's another link to help understand what's going on with the best part at the bottom under the "Cylinder Bore Refinishing" header: http://www.babcox.com/editorial/ar/eb90329.htm
Keep reading all the way to the bottom (Analyzing Cylinder Bore Finishes) to get an understanding of the terms used in the "Refinishing" section. One thing they didn't explain was the concept of "Plateau Finish". If you could put the cylinder wall after initial honing under an Electron Microscope (which somebody else referred to in another post here about the surface of the gears), it would look like the Rocky Mountains with the peaks and valleys. When the final hone is done for the moly rings, the peaks are "knocked down" and again, under the microscope, the surface now looks like the tops of the mountains have been taken off: plateaus.
Here is a small pertinent excerpt: "Federal-Mogul’s Gabrielson says a "plateau finish" is the optimum bore finish for today’s moly-faced rings. A plateau bore finish is what all types of rings eventually produce when they are fully seated, so the closer the bore can be prefinished to a plateau-like condition the less the rings and cylinders will wear as the engine breaks in, the better the rings will seal right from the start, and the longer the rings will last."
Basically, the plateau finish is what all cylinder walls look like AFTER break-in...so the moly rings are ahead of the game by starting with the plateau finish or ring sealing has already been achieved when you pick up your new car/start your new engine. Happy reading!

terryszr1

So you got a new motor ? what is it i know the guy @F.P.S. use 20 w for the break in for 20 min they get them good and hot 200 . then shut them down . and put in what they will run @ the track. hope this helps

cv67

Slipper, was hoping you'd pipe in...The motor is a few years old, Ive just never fired it up,hopint to have it going soon. Have a ton of $ in it and want it right from the get-go . It has Moly 1/16 rings in it and will be spun pretty hard (7500 rpm). The finish appeared to be pretty fine.