Correct oil for TR's given current zinc issues....

I am certain this has been covered but I could not find the posts in my search. What is the general feeling these days on the correct engine oil for pre-catalyst TR's? All of the oil producers have been forced to significantly reduce essential lubricants needed by many older flat tappet engines to meet with more demanding catalyst warantee requirements. This applies to many of the oils recommended for our motors 30 years ago - including Castrol GTX.

Two solutions seem at hand, perhaps there are others:
1) use Castrol Syntec 20-50 made solely for the needs of these older engines
2) use an additive such as ZDDP which replaces the needed zinc and other lubricants needed by our engines.

What is the current feeling on this issue?

Thanks.

A large and thorny topic, Ned, much more complicated than your summary would make it seem. Personally, I've been using Valvoline full synthetic 20W50 for many years, and see no reason to change.

I used Shell Rotella Triple T (Diesel with ZDDP) for break-in and a few changes after, per machine shop recommendations. I have a case of Classic oil from Moss to use up after and a case of Castrol Syntec 20/50 for flat tappets as you mentioned above. It's a toss up as to which one I'll go to after this oil is changed later in the summer.

Brad Penn is another well recommended oil for these. If you like green oil....

I use Brad Penn "green racing Oil". Already has zinc in it and a lot of racers use it.

See? I told ya!!

I grew up in western PA, so I like the oil from that area.

i've been running Castrol 20-50 in the TR6,
but switched to Valvoline VR1 Racing 20-50.It's a
little more expensive,but I don't put that many
miles on it.And besides,it's not hard to find.

- Doug

VR1 20/50 as well.

Cheers,
M. Pied Lourd

M_Pied_Lourd said:

VR1 20/50 as well.

Cheers,
M. Pied Lourd

Click to expand...

+ another 1.

+1 more.

Well, 10 years with my TR4A following a rebuild I used a diesel spec Pennzoil 15W/40 for a long time which has high levels of zinc as well as very high levels of detergents.

I have recently moved over plain old Castrol GTX 20W/50 with ZDDPlus additive.

Two observations from all of my reading and research on this subject:
1) Zinc levels are most important on initial break-in for sure. However, the benefits of high zinc levels are still not as clear after that break-in. However, the conservative in me continues to supplement the zinc levels
2) the zinc is sacrificial in nature meaning you only really need high zinc levels if you are running long intervals on your oil changes. For someone like me who drives ~1000 miles per year and changes the oil at the end of each season, it's probably a non-issue. But again, the conservative in me supplements my zinc levels with ZDDPlus.

Bob

It was explained to me last year by a Brad Penn distributor that many of the 15w-40 Diesel Oils would be losing their ZDDP over time. Make sure to check your labels at purchase. Unless specified, all road going oils were to be losing ZDDP.
Racing Oils are generally safe since they aren't sold for on road vehicles. I use Brad Penn 20w-50 Racing "Green" Oil as mentioned earlier. For start up on my new engine, I will be using Brad Penn 30w Break In Oil.

I don't often chime in on ZDDP threads because there is no consensus and even the studies out there can point at conflicting conclusions.

That said, for my British cars I use Castrol GTX 20W50... and then I add... STP-Red. Yes, STP, the snake oil from our childhood. Forgetting all the bad press about the company and all the company's self promotional hype, the factory states that their products do include high levels of ZDDP. It's a fraction of the cost of additives marketed exclusively as ZDDP replacements and it is available almost everywhere.

We use Brad Penn in the Formula-Vee but as stated above it costs more. If you don't want to use STP or the other additives you will not be disappointed with Brad Penn.

I bought my current Herald driver in 2002 with 50,000 original miles on it. Best I know, the engine had never been touched, and it hasn't since I've owned it. I've put over 30,000 miles on it in the last seven years. All I've ever used is Castrol GTX 20w/50 (sometimes a lighter weight in late fall or early spring). In the last several years, I've used the "High Mileage" version of GTX.

Given that the willing little 40 hp 1147 has to work pretty hard in today's traffic compared to even most other Triumphs, nonetheless I've yet to see anything approaching a problem with flat tappets from lack of ZDDP, nor have I seen any trace of valve seat recession from lack of lead in the gasoline.

Maybe I'm lucky...maybe I'm due. Maybe there's a bit of "hype" out there....

I bought my current Herald driver in 2002 with 50,000 original miles on it. Best I know, the engine had never been touched, and it hasn't since I've owned it. I've put over 30,000 miles on it in the last seven years. All I've ever used is Castrol GTX 20w/50 (sometimes a lighter weight in late fall or early spring). In the last several years, I've used the "High Mileage" version of GTX.

Given that the willing little 40 hp 1147 has to work pretty hard in today's traffic compared to even most other Triumphs, nonetheless I've yet to see anything approaching a problem with flat tappets from lack of ZDDP, nor have I seen any trace of valve seat recession from lack of lead in the gasoline.

Maybe I'm lucky...maybe I'm due. Maybe there's a bit of "hype" out there....

Andrew Mace said:

Maybe there's a bit of "hype" out there....

Click to expand...

Or a lot!

Great responses - thanks. This is one that could have quietly slipped beneath the radar but it seems everyone has been following the topic.

How were we to find out that producers have significantly reduced the zinc from all oils specified for new unleaded fuel cars to comply with the Fed's demanding 150,000 mile catalyst life? Even the trusty oils from just a few years back - like GTX - have been reformulated. Here I always thought oils were constantly improving, but in light of this discussion, and perhaps the unique needs of older cars, the word "improving" is questionable.

Thanks again for the input - and speedy response.

bunzil said:

Here I always thought oils were constantly improving,

Click to expand...

As usual, it depends on your definition of "improved". If your goal is to reduce emissions, and fuel consumption; then getting old cars off the road is an "improvement".

Mark Macy has a extensive discussion on ZDDP. www.macysgarage.com
Once at the site go to the Tech Talk tab

Lou Metelko
Auburn, Indiana

ZDDP concentrations in motor oil have been reduced in the latest SM classification from a previous maximum of 0.14% to a current standard of less than 0.08%, with most SM oils between 0.06 and 0.08% although some are lower. That's a reduction on the order of 50%.

There are likely to be further reductions in ZDDP in the coming years, however, and this teapot tempest may be an issue in future. ZDDP concentrations in the SM range (0.06-0.08%) are adequate to protect cam wear in engines with valve lifter pressures of roughly less than 475 lbs., which are not exceeded by very many stock motors (<span style="font-style: italic">for instance my TR6's valves operate at roughly a little less than 200 lbs</span>). The current situation is probably much ado about nothing for all but a very few engines among stock vehicles. High performance/modified engines are another matter entirely. This can be seen by reading between the lines in even the very promotional literature used for ZDDP additive products, for instance see: ZDDP and Cam Wear, Just Another Engine Myth?.

ZDDP concentrations higher than 0.2% actually attack the metallurgical makeup of iron in camshafts, causing camshaft spalling. So too much ZDDP is actually <span style="font-weight: bold">much worse</span> than not enough. Using these additives can be a risky form of roulette, like many "snake oils".