It looks like conventional oil. Plenty of ZDDP & Phosphorus. It looks that way to me. Read for yourself:

https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/D020D7BFB1CB34448025867E0048D3EA/$File/WEPP-BYBE6A.pdf

 

Hi Cub, I read earlier today, where an MG or MGB owner said it appeared to only have about half of the ZDDP required. However seems strange that a knowledgeable oil company would not put the proper amount in their retro oil product and then advertise it for classic cars/per-catalytic converter cars. Hoping to hear from some members that have had experience with this product, not sure how long this product has been around, guess it is just the same thing , perhpas under a different name ,that they sold back in the day when all cars required this type of oil. Thanks for your feed back......Carl

 

That is the oil we use to break in our race engines. Normally a weekend ,change oil filter,oil and clean the acusump and go to Redline 40 race oil.

 

Do you add any ZDDP to the Redline 40 race oil? Thanks.

 

No reason to. It’s already high zinc/high phosphorous, but for racing only. Low detergent means it’s unsuitable for street use.

 

Royal Purple has a synthetic called HPS, which has high levels of ZDDP and their additive called synerlec. I’ve seen an independent test of RP and something about their synerlec seems to allow the oil to help metals polish each other. That’s the best way to describe it. All other oils had a wear pattern. Something to think about and I can probably find the PDF of the oil test if someone wants it.

 

That is the stuff i put in my 70. Drove to Carlisle and back last year(1400 miles) then back and forth to work (60 miles) for a couple weeks. Related or unrelated since i have no history with the internals of the motor - i started having serious blowby and oil temps were climbing pretty high. I couldn't find any regular Castrol 20-50 at the time so i settled for the "classic". i did use a little ZDDP additive. I don't think you can have to much.

Tearing into a few things recently and i drained the oil and its the typical black but doesn't smell burnt or have any weird stuff from the looks of it. I am going to use again since i have a couple jugs of this. I trust the Castrol brand in the majority of my cars and motorcycle.

 

Castrol GTX Classic 20W-50 Conventional Motor Oil, 5 Quarts:
Walmart lists 5-quart container at $19.32.
Surprised that tree-hugging California Walmart sells it locally.

 

I didn't find the specific zinc/phosphorus content in the tech sheets for Castrol GTX Classic 20W-50W. But if Castrol sells it for flat tappet engines, then it seems likely that it has at least the "requisite" amount of ZDDP ( Zinc dialkyldithiophosphate). The identifiable and important parts of that compound are the zinc and the phosphorus.

And what is the requisite amount of ZDDP? Seems to be a bit of varied opinion on the subject, but generally, between 1200 and 1800 ppm of EACH of zinc and phosphorus are recommended for flat tappet engines. More for higher valve spring pressures and higher lift cams, less for less.

And how much is "too much" ZDDP and why? Generally, more than 2000 ppm of either, but especially phosphorus, is considered to be a problem. In simple terms, too much ZDDP makes an oil excessively acidic. Specifically, it is the phosphorus that is acidic, not so much the zinc. An excessively acidic oil can CAUSE cam lobe and lifter face degradation. But the degree of harm as the ZDDP concentration increases is a LOT less than insufficient ZDDP.

Not enough ZDDP will kill a flat tappet engine.

Too much ZDDP "may" harm an engine, but not nearly as much or as fast as none.

The degree of "excessive ZDDP problem" also will vary according to the composition of the oil additives and the oil condition. Oil with a high TBN (Total Base Number) has more buffering and will tolerate higher ZDDP concentrations, as it has the capacity to offset the acidity. New oil, by its nature, will have a high TBN.

Oil with too high a TAN (Total Acid Number) is already quite acidic, so having excessive ZDDP in OLD oil (oil with a lowered TBN and an increased TAN) may cause a problem with corrosion-induced cam lobe and lifter failure. So running oil an extended mileage on flat tappet engines, even with the "correct" amount of ZDDP, can be problematic. Even if your oil "looks" ok at 5000 miles, it may be excessively acidic. Only a proper oil analysis can determine that, and in most cases, it is cheaper to simply change the oil.

I ran the Lucas Hot Rod Classic High Zinc 10W-40 oil plus a half bottle of Lucas TB ZDDP additive for the first 5,000 km (3,000 miles) on my rebuilt Opel engine. But I am a big believer in synthetic oils (more stable at high temperatures, better additive packages, better lubricity, wider viscosity without excessive viscosity modifiers that inherently break down.). So I went looking for a full synthetic oil. The answer is in diesel oils, that are allowed ZDDP since they do not have catalytic converters.

I am currently using Mobil Delvac 1 ESP 5W-40 with a half bottle of the Lucas ZDDP additive. It has 1000 ppm zinc and phosphorous (hence the additive). The engine runs at least 10 C cooler (I have an oil temp sensor), seems quieter, and the oil is still a light brown after 2500 km.

HTH.

 

I always have to butt in and offer a differing opinion on the ZDDP debate. Modern oils are designed be backwards compatible and all modern oils of the correct viscosity are adequate for STOCK flat tappet cams. If you have intensified valve springs or high lift cams you MAY need more sulfur. Zinc isn’t really important, but the sulfur and phosphorus in ZDP actually do coat wear items nicely.

So here’s the fun part that none of the big oil companies will put out there:
Modern oils are tested by the API using an ASTM test Sequence IIIG. Guess what? This test is run on a FLAT TAPPET V6 at a brutal 100 hours of 302° oil temp.

so I don’t run special oil in my cars except for my race car because it sees long stretches of zero pressure and high temp while cornering. I feel like the extra ZDP helps in this case, but I have no proof.

Again the info I give above only applies to stock cams and valve spring intensities. Higher spring pressures and cam lift changes things outside of the API test criteria. Always follow your cam manufacturers break-in procedure too (even if it doesn’t make any sense).

 

I always have to butt in and offer a differing opinion on the ZDDP debate.

I would recommend reading this article by Engine Builder Mag. It dives into the ZDDP issue rather well. It takes like 5 minutes to read.

ZDDP: When, Where, What, Why, How? - Engine Builder Magazine

Government regulations and demands for lower emissions levels become more important than power and performance. Proven components are no longer acceptable and the inevitable changes occur – not always for the best. Related Articles - Which Sedan Engines Are Least Accident Prone? - Stefan Rossi...

www.enginebuildermag.com

Something else to consider, beyond how the oils are tested is the use of the vehicle. Vehicles that are used daily are bound to have plenty of residual oil still on high wear surfaces the next time you start the engine. But classic cars that aren't driven daily and only really see use on the weekends, could go a week or two before the next time the engine is started. This provides a lot more time for oil to drip off of high wear surfaces and for the remaining oil film to oxidize and dry out. This is when you want a high ZDDP oil, so more ZDDP is on these high wear surfaces. The vast majority, like 90%, of engine wear happens during start up and getting the oil up to temp. Once the oil is properly up to temp, very little wear should happen on an engine as the oil should coat everything rather nicely at that point, at least if the oil doesn't need to be replaced.

I'm attaching an independent oil test that was done on dozens of oils. The results of this test are why I'm a fan of Royal Purple for engine oils. Yes, this isn't the only test that matters with oil. As always, decide for yourself. None of us are by any means experts on oil and oil discussions can be a bit like politics and religion. I know enough that I'll use Royal Purple's HPS which has a high ZDDP content with my 2.4L build after using their break-in oil. Seeing really is believing.

 

After reading extensively on this subject (and I do not nearly as good of an understanding as what Keith has) I decided to not play chemist & go with the Brad Penn partial synthetic since driving my rebuilt engine. It doesn’t cost much to do so twice a year or so I get my oil tested to see where things are at.

I used Castrol partial synthetic for years on my 1.9 up until I removed & rebuilt it a few years ago. I had no unusual cam wear with a near stock cam, stock springs & hydraulic lifters & never added ZDDP.

Here’s a good read 🙂 that will compliment Autoholics post

 

Kyler, I have found something I think you'll like to read. It's all about engine oil myths and they dive into the ZDDP debate, and they quote test data. Oh, and they provided their sources too. I found this by Googling "is zddp necessary".

https://www.kirbanperformance.com/product_images/customer_support_item-_pdf-35.pdf

The above resource, made me question my own understanding of a few things by the way. I think it's worth reading for anyone interested in this discussion. I'll still go with a higher ZDDP oil, but it does support Kyler's belief that running a SM or SN oil should be fine in your engine. They were meant to be backward compatible for street use. Because my engine isn't remotely stock, I'm going to use an oil with more ZDDP to protect against high lifter loads.

 

Thanks for this article. This is good stuff and both authors in the article have great points. I would caution taking stock in the percentages of phosphorus required for specific spring pressures that was cited in the article. I checked that source and it was from 1958! Oils in the 50s were… less than good…
I would be interested in seeing the same curve using oils of the current century. I wouldn’t be surprised if the curve was drastically better now with some of the new wear additives available today.

Anyway on the topic of the best oil for a modified Opel engine I REALLY like my Redline 10w40. It has plenty of zinc and maintains oil pressure much longer than any other oil I’ve tried. It also handles high heat fantastically without dropping pressures.
It still has like new pressures after a full season of racing.

Royal purples ZDDP rich oil also worked well in my car, but the oil did not handle high temps well and would have low pressures after long trips. It made it through about half a season of racing before I noticed lower pressures.

Valvoline VR1 is the worst single racing oil I’ve used. I have previously recommended it, but no longer do. It’s fine in a street driven car in temps between 50-80°F and that’s it. It degrades very quickly and has terrible high temperature characteristics on the track. In cold temperatures it is (possibly?) dangerously thick and makes cold starts difficult.

All of these oils are SM or SN rated so they are safe to use though. I just like some more than others.

 

To clarify by “the ZDDP thing being a myth” I mean flat tappet engines requiring excess amounts of it above 700-800ppm that are in all modern oils and oils prior to 1970. Keep in mind I’m still not including after market modifications like high valve spring pressures in this statement. Modify cars takes them out of the carefully tested standard oils and may require specialty oil (just like modified engines need special fuels, or meth injection often).

And all modern oils are designed to be backwards compatible at least to a high degree. That is one of the biggest things the API pushes. The tests they run are tailored to ensure you can continue to use modern cleaner oils in older machinery as well as modern engines.

 

After reading thru this lengthy article I switched to 10w-30 full synthetic 5 years ago with no issues.

540 RAT - Tech Facts, NOT Myths

540ratblog.wordpress.com

 

After reading thru this lengthy article I switched to 1w-30 full synthetic 5 years ago with no issues.

540 RAT - Tech Facts, NOT Myths

540ratblog.wordpress.com

In recent years there have been entirely too many wiped cam lobes and ruined lifter failures in traditional American flat tappet engines, even though a variety of well respected brand name parts were typically used. These failures involved people using various high zinc oils, various high zinc Break-In oils, various Diesel oils, and various oils with aftermarket zinc additives added to the oil. They believed that any high zinc oil concoction is all they needed for wear protection during flat tappet engine break-in and after break-in. But, all of those failures have proven over and over again, that their belief in high zinc was nothing more than a MYTH, just as my test data has shown.
.
A high level of zinc/phos is simply no guarantee of providing sufficient wear protection. And to make matters even worse, excessively high levels of zinc/phos can actually “cause” DAMAGE your engine, rather than “prevent” it. Motor Oil Industry testing has found that motor oils with more than 1,400 ppm ZDDP, INCREASED long-term wear. And it was also found that motor oils with more than 2,000 ppm ZDDP started attacking the grain boundaries in the iron, resulting in camshaft spalling (pitting and flaking). The ZDDP value is simply the average of the zinc and the phosphorus values, then rounded down to the nearest 100 ppm (parts per million).
.

 

Thanks everyone for sharing your research, comments, opinions, experience and recommendations, etc. Of course I really have no idea what is the correct direction to take after reviewing all of what was really great feed back, thanks again, but I agree with Autoholic, this subject is like politics and religion. Anyway one thing that I found very interesting and really jumped out at me was Keith's comment,"I am currently using Mobil Delvac 1 ESP 5W-40 with a half bottle of the Lucas ZDDP additive. It has 1000 ppm zinc and phosphorous (hence the additive). The engine runs at least 10 C cooler (I have an oil temp sensor), seems quieter, and the oil is still a light brown after 2500 km." My last oil and filter change was last week and produced a very, very black drainage - car has 4750 miles on the engine and the oil and filter change was after 1 year and around 1800 miles. I was surprised that the oil was so dark but really have no other point of reference except what Keith said above and that my 18 year old Lexus has never had really black oil even after 4500 miles which is the mileage point where I change my oil in that car. My theory is the oil companies recommend an oil change every 3000 miles for conventional oil and the owners manual recommends 7500 miles. Well the oil company sells oil and the car company sells cars, they both have very different agendas , so I split the difference with the Lexus changing the oil at 4500 miles. The Lexus currently has 230,000 miles on it and still purs like a kitten.
The oil that I drained out of my GT was the Castrol regular 20-50 with a bottle of the ZDDP from OGTS. The engine is a rebuilt purchased from OGTS in 1999- I believe it is a 1975 GM block and has a camshaft of .430" lift with a SOLID grind camshaft, installed with 1.72/1.50 Chevy valves and 2.0 (.030" OS) pistons. Perhaps next oil change I will give Keith's recommendation a go.

 

Well, regardless of the data, both positive and negative, I’ve had absolutely stellar results running the Brad Penn Racing oil (20W-50) in racing Opel engines at 3-times the stock HP level and at 8500-9500 rpms. Zero bearing and camshaft/lifter failures in 30 years.

If that doesn’t count for anything, I don’t know what does.

 

I've used various oils over the years, leaning towards ones with zinc, including a few changes using traditional diesel oil. I may wipe a cam lobe next week but I've not had any real problems out of any of them. Our cars probably get driven more than most. Infrequent short mileage trips don't do any engines much good.

My current oil chose is Schaeffers 15w40 Racing Oil, the thickest oil I've run in quite some time. No thank you to 20w50. I tried it once and it made my car noticeably more sluggish.

This link may answer a few questions asked and not asked. Ads are all over this site but do NOT require you to click on them for oil information.

Harold