There was some recent talk on the R3 Owners site regarding Shell Rotella and low zinc levels. Here's the original post:
So my Rocket went up to Carpenters for a checkup; was getting a tapping noise that was more pronounced this year. Bob and Eddie investigated and found that one of my cam lobes ate a tappet; and so my cams had to be pulled and sent out for rebuild, and the tappet has to be replaced.
All of my cam lobe surfaces did show varying degree's of wear; and after talking at length to Bob and doing some pretty intense investigation on my own part; have deduced the probability of this event to be caused by the Shell Rotella T6 that I have been using.
I found out that Shell lowered their Zinc content in the Synthetic T6 last year; as seemingly Mobil 1 had done with their synthetic as well (this is probably the reason why Triumph switched from Mobil 1 to Castrol synthetic...). Our engines are of a flat-tappet cam design, and the propensity for wear on the cam lobes and tappets are greatly increased; if the oil does not have sufficient zinc and phosphorous content.
Many common engine oils have reduced the zinc and phosphorous levels due to the damage they cause with catalytic converters and sensors; however other oils which are not commonly used such as racing, marine and diesel oils still have adequate amounts of the zinc and phosphorus to alleviate the wear that is more common with the flat-tappet cam engines.
If any of you Captains are running Shell Rotella T6 at this time; I would recommend that you seek another brand of oil with better zinc and phosphorous properties. Amsoil markets synthetic oil which contain higher amounts of zinc and phosphorous; Bob has recommended their 15W-40 Synthetic HeavyDuty Diesel and Marine Motor Oil, although I am going to discuss the Premium Protection 10W-40 Synthetic Motor Oil later with him.
http://www.amsoil.lube-direct.com/20...nc-oil-amsoil/
