Speaking of OIl

[Showgood1]

I did a service call at a auto shop today and the owner said that as of 2004 your friend and mine the government forced all oil manufacturers to leave out zinc and phosphoerous. He said that Crane and Competition cam companys started getting coverd up with calls about new cams going flat and that it would start causeing problems for anything with a flat tappet. He also said it doesn't affect roller cams. I kinda understand but what else would this affect? The D-max has a roller cam right? But what about all that torgue on smaller bearings? I guess this is a good one for Dr.Lee. Can anyone better explain the chemistry or what this might mean?

[jbplock]

Showgood,

This is an interesting topic! Dr Lee did an excellent write up on this subject a while back..

See Sulfur: Good, Bad or Ugly ? (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=16;t=000671)

and, Oil Supplement/Synthetic Oil ????? (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=16;t=000751)

Per Dr Lee's post in the first link, "Zinc" is added to motor oil in the form of zinc dithiophosphate, or ZDP. ZDP functions as an excellent anti-oxidant and anti-wear agent in lube oil. However when ZDP gets into the combustion chamber, it produces some sulfur and phosphorus, which can harm catalytic converters. So ZDP content in lube oils is being reduced.

Dr Lee also points out that adding a little STP is one way of boosting ZDP levels but it also adds VI (Viscosity Index) improvers (thickeners).

Another option for boosting ZDP is a Power Service product called Diesel Lube Oil Extender (http://www.powerservice.com/diesellube_oilextender.asp). This product contains ZDP without the VI improvers. (see my post in the second link above for more details)

There is also some info on this subject over at BobIsTheOilGuy.com. They have some dedicated forums where folks post their oil analysis reports. In the Oil analysis forums (http://theoildrop.server101.com/cgi/ultimatebb.cgi?category=4) there is a link to the BITOG VOA Library (http://www.bobistheoilguy.com/voalibrary.html) in which you can see that the Heavy Duty Diesel Engine Oils (HDEO's) still have respectable amounts of ZDP compared to the Gasoline Engine oils. In fact many folks over there run HDEO's in there gas engines to get the benefits of the heartier additive package.

Since ZDP levels in the HDEO's are still fairly good I haven't been adding any ZDP to my Duramax (1368ppm in the M1 T&SUV I'm running ). However I did add some Power service DLOE to the M1 5w30 in my 04 Impala's 3.4L V6. I did a "before" UOA and will be doing an "after" UOA to see if there is any improvement. ZDP levels in M1 5w30 are 775ppm and 1058ppm in the new M1 Extended Performance 5W30.

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[ 07-14-2005, 08:38 AM: Message edited by: jbplock ]

[Jim Brzozowski]

Yes, the Dmax has a roller cam. The problem is that flat tappet and cam lobes are both steel. Loss of lubrication for a few seconds can be devistating. The hardened surface of the cam and lifter are soooo very thin. Once through that hardened material it won't last long.

Bearing surfaces are a combination of Aluminum and other alloys added in that are basically softer than the steel that rides on them so not as much a problem, the aluminum becomes the sacrificial material and will wear before your expensive crank or camshaft bearing surfaces. Also the Major Refiners knew about this well in advance and as long as you stick with major brand oils, you don't have to worry.

[Showgood1]

That guy I talked to also said that there is still plenty of ZDP in "Raceing Oils" such as the one from valvoline. But of course its illegal to run in a street car. I guess they'll have start sticking the oil pan looking for the wrong oil just like they do when they are after off highway diesel. There is a local concrete company I know of who has 4 trucks (350's) all with over 300k on them two have over 600k on origanal engines! The diesel in the goat rig still runs but the truck don't. So far only 1 D-max but I think it just now turned over 150k so I guess we can't count that...yet. They buy Rotella by the 55gal drum and run it in everything. Coincidence or just the 'ol bow tie just doing its job?