Here's an interesting quote from the link I posted above....
"**NOTE: The zinc and phosphorus anti-wear levels of all oil in this list, are elemental values, which are NOT the same as ZDDP values. Earlier oil industry testing found that above .14% or 1,400 ppm, ZDDP INCREASED long term wear, even though break-in wear was reduced. And it was also found that .20% or 2,000 ppm ZDDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.
But the correlation between elemental values and ZDDP values varies by motor oil manufacturer, and they do NOT publish their ZDDP values. That makes it difficult to impossible for the consumer to know how elemental and ZDDP values actually compare for any particular oil. However, these elemental values are high enough here, that this oil really is only suited for short life dedicated racing engines, as the name implies. Using zinc/phos levels this high in other engines could be cause for concern, since excessively high levels, used for more than just break-in, can “cause” engine damage rather than “prevent” it."
The second paragraph is talking about Lucas and Redline racing oils. This is according to the Staveley Labs who conducted the testing.
First I would like to slap Matt for Shawn and myself. If it was up to him he would install a coal fired boiler and all the running gear in his heep and Jeep Forum would be stone tablets!
My suggestion to you is go to a GM dealership and see if they can get you a bottle of EOS engine oil supplement. They quit making it a few years back because all new cars have roller cams in them so its not needed. They can look up in their computer who has the stuff and bring it in for you. Its about $30.00 for a pint. But it was the best for breaking in cams. Eldlebrok also make a version so does Comp Cams. If you get the additive just run any old decent oil and that is the least expensive way to go. O Riely and places like that can order it for you.
The camshaft is a type of cast iron and the lifter is hardened steel and since they are dissimilar metals the idea is that you want to seat the lifters in the cam and get the lifters spinning. Think of it as the cam rotates the lifter spins or walks around the edge of the camshaft. The lifter will eventually get a slight rocker shape on the bottom of the lifter and the cam will also wear to match the rocker. The lifters and cam lobe will develop small ridges like an old phonograph record but each lifter will have its own unique pattern and thats why they cant be swaped.
The reason they want 2000 RPMs is that is the RPM band were the spring pressure has the least amount of pressure on the cam shaft. The lifters are pretty much floating on the cam (think of hydro planing in your car your on the road and water at the same time)
An old successful engine builder thought me this trick on break ins which is different that the start it and run it for 2000-3000 RPM for 20-30 minutes. He told me to start the engine and run it for say 10 seconds stop the engine and let it cool all the way down to ambient temperature. The next run cycle double the time to 20 seconds and let is cool down to ambient temp. The next cycle run it for 40 seconds each time doubling the previous run times till you hit you 20-30 min run times. This is a less stressful breakin than running it straight through for your 20-30 min breakin.
I have done it both ways and I like the stop start method better for several reasons. One is it allows you time to make timing adjustments, adjust your carb or any thing else like a little water leak. It also has sound metallurgical reasons the short heat and cool cycles help establish a excellent breakin pattern and also helps temper the metal (just like when you break in a ring and pinon gear)
Either way will work I like the start stop method its a lot less stressful than running around your engine with glowing orange headers, timing thats off and a carb that needs a bit of tweaking.
It's interesting. There seems to be a bit "black magic" around the whole break-in procedure. Every experienced engine-builder seems to have his own little wrinkle. My dyno guys had a similar stop/start method, only with longer periods. I think they did 1 minute, then 5 minutes, then 10, then 20 with cool down periods in-between as they tweaked the tuning.
Rotella wont make a difference I would use a 30 weight quality oil like Valvoline or similar. Since the breakin is more or less a machining process to seat the rings and breakin the cam it wont be in there for more than the breakin period. Also Rotella and other diesel engine oils have lowered their ZDDP over the years due to the EPA I dont think its the miracle oil like it once was.
Also the high detergent might negate some of the breakin additives so if you want to run Rotella after breakin I dont see being a problem.
Also Rotella and other diesel engine oils have lowered their ZDDP over the years due to the EPA I dont think its the miracle oil like it once was.
Agreed. The CJ4 rating to meet 2007 emissions standards killed the levels of ZDDP in diesel oils. The only reason to run it now in a gas engine is for higher detergent levels, which as you say are N/A on a new rebuild.