Hey guys, fresh rebuild. 95 Z28, LE2, custom ground cam 224/230.

I am using Rotella 15w40 for the first 25 miles or so, but my oil pressure is really high for some reason. Is this okay?

http://www.youtube.com/watch?v=n8eElX-mO7o

 

What oil pump/pressure spring are you using?

 

I believe it is whatever was stock, unless the machinist upgraded it during the rebuild without telling me.

 

Fresh build at stock bearing tolerances, I don't see anything wrong with it. What kind of pressure are you holding hot?

 

Pat of it is the 15W portion of the oil spec - the cold oil viscosity. That's a lot heavier when cold than the factory recommended 5W or 10W oil. My engine was rebuilt to use 20W-50 for drag racing, but street use in the winter they recommended a switch to 10W-30, to provide the required low temperature flow at startup. High pressure is often the sign of high viscosity.

 

Well this oil was recommended to me for about 25 miles for break in, followed by an oil change with normal oil. Is this high oil pressure safe for that 25 miles?

 

typically i hear for break in period just dont give it alot of throttle, not a high viscosity grade of oil. your oil pressure is pretty dang high, id switch it back to 5w-30, and perhaps adding in some of the synthetic blend lucas oil stabilizer http://www.lucasoil.com/products/dis...how&headTitle= - Lucas Synthetic Oil Stabilizer somebody correct me if im wrong

 

Lucas is thick oil with basically no additive package. You want your oil thicker use a thicker oil because an actual engine oil has beneficial additives.

 

This doesn't have anything to do with oil pressure, but to comment on what oneclean97z said about break-in, the LAST thing you should do is be gentle on it. You should drive it like normal doing several 3/4 throttle runs and then some. Being gentle with low RPMs and lots of idle time is a good way to ruin the rings.

 

I don't see why anyone would make that recommendation, but as long as you don't beat on it while the oil is still cold it won't hurt anything.

Rich

 

Today's oil is missing Zinc
This is cheap insurance

 

ZDDP (zinc) is more important to flat tappets and I don't know many people putting flat tappets in LT1s.

 

If you want to keep thinking that way that's your prerogative. Just don't try to make an *** out of me while you do it.

 

I actually think the concern is the lack of Phosphorus, not Zinc, in newer oils. Phosphorus is extremely important in high sheer environments for use as an anti-wear ingredient...like the flat tappet lifters that Dwayne mentions but also in the thrust bearing areas. As it turns out, both you guys are right....

The additive that is now offered as break in oil is ZDDP. That's Zinc Dialkyldithiophosphates for you chemists out there. The main reason they were "removed" from oils was that zinc and phosphorus poison catalytic convertors. The quotes around the removed is bacause they're still in many oils, including Mobil 1, at levels lower that the maximum imposed by the EPA.

The bottom line, for me, is that in roller cam engines you probably don't need it for break-in and certainly not for normal use. It is my opinion that quality oils have enough in them to get the job done. It doesn't, of course, hurt anything to add them, though.....

Again, just my opinion....

 

Well I have lost spark, so this problem is on the back burner for now =(