Steel Soldiers::Military Vehicles Supersite - View Single Post - Engine oil mythology debunked, and ZDP content

darknessvanquished · 09-13-2009, 14:02

Quote:

Originally Posted by Tanner

Those of us that participate in the air-cooled VW & Porsche engine community & build engines have had flat tappet cam wear issues typically attributed to a lessening of ZDP in the oils... it isn't anecdotal - I just looked at a Type 4 VW/Porsche motor Wednesday that had no more than 10 hours on it & the new cam & lifters were majorly damaged. Multiple cam/lifter failure stories from performance engine builders have surfaced on the VW forums, and these are from guys that build some of the top motors in the country - I doubt that they would lie about the oils used.

Most of us were/are using Rotella, but the ZDP content in it was recently reduced.

Let me see...
Engines built & using oil with greater amounts of ZDP > very few to no cam/lifter issues.
Engines built & using oil with less ZDP > more cam/lifter failures.

Coincidence?

Tanner

Decreased levels of ZDDP are 100% related to flat tappet camshaft wear and failures. ALL of the people in the engine industry know this. EVERY major camshaft manufacturer has issued bulletins on this with the warning to use ZDDP fortified oil or a ZDDP supplement or else you will ruin the cam and lifters. Point blank-It's either run a oil with ZDDP to keep your cam alive or upgrade to a roller cam setup that doesn't "require" the higher level of ZDDP. Even then, I'm a tad skeptical because there's a whole bunch of friction between the lifter's rollers and cam lobes when you are running valve springs with a lot of tension, as is typical in a roller setup, especially with a solid roller cam-they run very stiff springs. Play it safe and run a ZDDP fortified oil for maximum protection regardless if it's a flat or roller cam. Oil is cheap, tearing apart a engine and replacing parts isn't.

Yes, diesel oil has had its ZDDP levels reduced in the past couple of years, but ZDDP is still in there at levels 3-4 times what is in API certified "gasoline" motor oil. Diesel oil for the time being is a excellent way to get ZDDP if you don't want to pay a premium price for boutique oils like Brad Penn, Royal Purple, etc. I run Shell Rotella 5W40 diesel oil in all of my flat tappet cam engines, a 1997 Jeep 4.0 6cyl being the latest model engine to use it.