TR6 pros and cons of zinc additive

[sundown]

Can I get feedback on the zinc additive I currently run Castrols 20/50 never even thought to check the whats in it?

 

[TR3driver]

IMO you should stay away from oil "additives". The oil already contains a quite complex package of various additives, all of which interact to some extent. Throwing another random additive into the mix may have unexpected side effects, like sludge formation or loss of viscosity. If you are convinced that your engine needs more zinc than your current oil has, you should switch to one of the many "high zinc" oils on the market.

I am convinced that some engines need the higher levels of zinc (ZDDP). But I'm not convinced that stock Triumph engines fall into that category. The ones that do are mostly either engines that have been modified with more aggressive camshafts and/or higher valve pressures; or stock engines where the OEM did the same thing.

Still, it's cheaper to buy a quality "classic" oil than to replace the cam & lifters. I've been using Valvoline VR1, which has the higher zinc levels and occasionally goes on sale for $6/quart at Autozone. Looks good so far, but it's kind of hard to tell since I'm running a "barn find" engine.

 

[charleyf]

When the info first came out about zinc in the oil or actually lack of zinc in the new oils, I read a lot about it and came to the conclusion that the newer oils have significantly changed. Though I understand Randall's concern, I use the ZDDP additive in my TR's. Zinc is needed however you get the zinc in there .
Charley

 

[glemon]

I used to use Castrol 20w-50, but got Valvoline VR1 for my last oil change after reading a LOT of information on the web and here on the forum, it sounds like it is the best "name brand, off the shelf" oil for ZDDP these days. If you really want to make sure you have enough you can go Brad Penn but that has gotten pretty pricey. Although I don't know that I feel so strongly that I would never try it, I tend to agree with Randall about additives, oil companies spend a lot R & D time and money formulating their oils, will and additive upset the delicate balance and do more harm than good? Don't know, but I am more comfortable buying a premium oil than an off the shelf regular product and adding something.

Will also add after re-reading the original question that Castrol came up pretty good in my research, probably second best of the common oils after the VR1, will also add that formulations have changed a lot over the last five years or so, so try to find dates on the stuff you read, if you do your own research.

 

[mikephillips]

The zinc as I understand is more necessary for older engines that run a flat tappet type cam. Those that have switched to or originally had a roller type probably won't need it. I've seen a lot of stories about excessive wear for the flat tappet type, seems the current formulations aren't protecting them very well since modern engines don't need it. There are probably studies out there if you want to search for them. I personallt feel better with something that has higher zinc, either by way of specialty oil or adding it.

 

[tomshobby]

When I purchased my TR6 several years ago it had engine problems and I knew a rebuild was needed. Knew it going in and much preferred rather than buying one that just had an engine rebuild. Anyway, it had three badly worn lobes on the cam and the lifters were trashed. A couple of the exhaust seats were also in pretty bad shape and 2 top rings were broken and the corresponding pistons were broken.

After an extensive rebuild I was determined to use oil with a good amount of ZDDP. First I did a lot of research to better understand what was a good level of ZDDP. Then actually called some oil companies and talked to their engineers to find what levels they had. I found an oil that was in a range that I was comfortable with. After a couple years I changed to what I consider a better brand and am very happy with it.

I agree with gleman about doing some research and those talking about not using an additive. There seems to be a rather limited range of ZDDP content that is beneficial and being lower or higher can be not so good.

 

[TR3driver]

There seems to be a rather limited range of ZDDP content that is beneficial and being lower or higher can be not so good.

Excellent point, too much can definitely be harmful.