zinc & classic oil claims

[Nambo]

I run all my classic vehicles, (Brit bikes and the Stag, also a Herald and a Vitesse when I had them), on Fully Synetic, swear by the stuff, never any problem.
My friend with a Mach 2 Mustang however, has just informed me his Mustang ate all its cam followers on Mobil 1 and that his contacts informed him it was the lack of Zinc in modern oils, he informed me that he subsequently drained and threw away his Mobil 1 from all his vehicles.
I though, decided to do some investigation.

The following is the initial inquiry and response from Mobil tech that seem to have gone a long way down a hill since I last spoke to them:-

So I e-mailed Mobil tech inquiries English office the following:-

For many years now I run 5 old English motorcycles and a Triumph Stag car
on Mobil 1 15/50 I have advised my friends to do the same.
However one friend reports the cam followers have gone on his Mach 2 Ford
Mustang and a shop has told him its because he uses modern synthetic oil
that does not contain enough zinc he has subsequently removed your oil
from all his vehicles.
Can you comment on this please if this is the case is there a zinc
additive that can be used with your oil?
I understand in America there is a Mobil 1 oil for V twins that might be
more suitable for old vehicles is this the case and can it be purchased
here in the UK.
Thank you

And this is the reply I received:- (copy and pasted)

Dear Mr. Charlton,

To give you some comment and advise we have not enough information,
concerning your problem. We have to know thich cars/models/ you are talking
about.
We can advice which oil schould be used in regular cars in normal
conditions and if you know the neded/requested specifikation of the
vehicle.


Regards


In the end after a few such e-mails I got them to admit there is "little or no Zinc in Mobil 1 but that they have other additives to help improve wear and other features.

From other sources I gleaned that the main problem is with vehicles with flat cam followers, though my BSA has such followers and I have not had a problem, shouldn't be a problem with the Stag valve mechanism, just to be on the safe side however, I have purchased an amount of ZDDPLUS.

[DJT]

If that is the quality of reply from Mobil, it would encourage me to avoid their products like the plague. The Stag engine was designed and built with 20W50 mineral oil in mind. As this is readily available (VR1, Millers, Halfords, etc.) why not use it?

[wilf]

The Stag overhead cam lobe's mechanical action on the buckets is exactly the same as a flat tappet, and so will benefit from the anti-scuff properties of ZDDP.

[Nambo]

If that is the quality of reply from Mobil, it would encourage me to avoid their products like the plague. The Stag engine was designed and built with 20W50 mineral oil in mind. As this is readily available (VR1, Millers, Halfords, etc.) why not use it?

I could use the same argument for choosing a 40 year old tyre design.
Manufacturers specified what was available at the time, maybe if Synthetic oil had been available they would have specified that, the fact they didn't doesn't mean the oil is unsuitable as much as it means it wasn't invented at the time.

But here is why I use it.
I run old British motorbikes, you are not at all isolated from how the engine feels.
In the old days when we used good mineral oils, following your 3000 mile oil change, the bike would feel as if a new engine had been fitted, it would be so smooth.
What this demonstrated to me was how badly the old oil had broken down, and how much damage it was therefore doing to your engine.
When I first started using Mobil 1, I found that even if I left that oil in for 10,000 miles, when I changed the oil I couldn't detect the slightest difference, that tells me that the old oil was still as good as the day I put it in.

Another example, I used to travel 50 miles a day in a neglected Herald, I did 12000 miles on that Fully synthetic, during that time on three occasions, the water had completely ran dry and I only noticed it when I went to turn the car off and found it carried on running with the heat.
When I drained that oil it still felt as thick and slippery as the day I put it in, and stripping and inspecting the engine, I could find no damage or heat discoloration.

The fact you shouldn't run in on Synthetic because its so good that the parts wont wear in to each other should tell you how much better these oils are at the job they are designed to do.

[martin]

The main reason for using high ZDDP 20/50 mineral oil, is that it does not drain down nearly as quickly as synthetic, it pools above the cam followers and saves you from the dreaded dry start. I'm not sure comparing an old thumper with a twin cam V8 is valid. If you're prepared to risk your camshafts to make a point, please carry on. Martin.

[Westfaling]

I talked to a Mobil rep recently and he suggested Mobil 1 10w 40 4 stroke motorcycle oil. Not sure I want to go to 10W40 but it has (apparently) higher zinc levels.
Nick

[ChasR]

Strangely enough, Opie Oils made a similar suggestion for the Mini I have (although I admit that was due to the fact that the engine and gearbox share the same oil.

On both the Mini and Stag however, he felt that 20W was too thick a weight for cold start protection (in his words, calling it treacle), especially at this time of year, suggesting a 15W oil instead.

Saying that, the Stag seems to run fine on 20W50 .

[Hughesy]

I have been using Mobil 1 V-Twin 20W-50 (4T oil) and am very happy with the performance and oil pressure.

I have also used Castrol Edge "Sport" 10W-60 in the past.

I found the following info from Castrol on another forum site. It is stating that Castrol Edge Sport 10W-60 is recommended for older classic engines with flat tappets. I am not sure of the date of this information so need to double check it against current oil specs.

[forums.pelicanparts.com]

Castrol also supplied the following writeup titled Modern Oils in Older Engines by Neil McTavish – Australian Automotive Technology Manager Castrol.

In recent times we have been asked by a number of people to comment on using the latest oils in older engines. Questions have come mainly from car clubs but also from some magazines, racers and engine builders. The questions relate to wear performance on flat tappet cams. Please note, all my comments in this article are about flat (sliding) tappets not roller followers, a different story.

Firstly let me remind people, this is Australia not the USA. I have read a number of articles where the information clearly comes from the USA but you are left with the impression that it is written about Australia. The internet can be misleading if the source of the information is not clear.
I have been in the technical area of lubricants in Australia for more than 30 years.
So I am familiar with engine oil formulations since the early 1970’s and have seen a lot of information on oil formulations back into the 1950’s.
Although Castrol is sold in more than 100 countries around the world, products and the range of products are not the same in all countries. The oils sold in Australia are not the same as the USA. There a range of reasons for that including different market needs, mix of vehicles and climatic conditions. The range and type of oils we sell in Australia are decided by people in the Australian business not by people in the USA or Europe. The people involved are a combination of Marketing, Sales and Technology. Our Sales and Marketing people are just as keen to have the best products that suit our market as we are in technology and you the customers’ desire for your vehicles.

There are two main industry oil qualification systems. These are API/ILSAC from USA and ACEA from Europe. Both of these systems are developed jointly between the oil industry and vehicle manufacturers. The updates reflect the latest requirements for standard vehicles and applications. The biggest influence most recently is the “Tier 2” emission regulations in the USA and Euro 4 in Europe.
These regulations do not come into place for petrol engines in Australia until between July 2008 and July 2010. The US petrol classifications have two types, ILSAC grades for GF-3, GF-4 etc. are; SAE 0w-30, 5w-30, 10w-30, 0w-20, 5w-20 and the rest, not ILSAC. The ILSAC requirements require improved fuel efficiency and have chemical limits on Phosphorus and Sulphur. API performance qualifications started at SB in the 1930s, currently the highest API petrol engine specification is SM. ACEA specifications are A1/B1, A3/B3, A3/B4 and A5/B5. ACEA C1, C2 and C3 are newer low Phosphorus specifications.
The Phosphorus is limited to help maximise the life of catalytic converters for long-term emission reduction. Sulphur mainly effects base oil type so I will not discuss it further here.

The main reason Phosphorus is added to engine oil is for cam and tappet wear protection. The most widely used form of Phosphorus in engine oils is in an organometallic molecule. The material is Zinc Dialkyl Dithio Phosphate, ZDDP or ZDTP for short. Useful molecules that include Sulphur and Phosphorus, they perform most of the antiwear protection on steel surfaces. The most recent API SM/ILSAC GF-4 grades have reduced the maximum allowable Phosphorus content to 0.08% (800 PPM, Parts per Million) from 0.10%, 1000 PPM. The 0.10% limit has been in place for approx. 15 years in the USA and since 1986 in Australia. Yes most petrol engine oils for more than 20 years in Australia have been 0.10% Phosphorus maximum. That was as a result of an agreement between the car industry and the oil industry in Australia. That engine oils for petrol engines would be 0.10% Phosphorus maximum. However most oils from the 1950’s and 60’s had lower Phosphorus content than even the latest passenger car engine oils, i.e. it was typically 0.06% which is even lower than the 0.08% limit set by API SM.

ZDDP is a multifunctional additive; it has powerful antioxidant effect in addition to the antiwear characteristics. The size and type of the alkyl group attached to the Thio phosphate within the molecule influences the relative antiwear antioxidant balance of ZDDP additive. Over time Castrol have used modified ZDDP’s that are more intended for wear performance and substituted other materials to boost antioxidant performance of our engine oils. So looking at Zinc and/or Phosphorus levels alone does not tell the full story in terms of wear protection.
The majority of the Castrol passenger car lubricants sold in Australia are ACEA qualified as well as API qualified. The ACEA requires extra valve train wear, VTW, tests over and above API requirements. In addition most of Castrol ACEA qualified products are 0.10% Phosphorus maximum. The same as we have used for 20 years or more. So that is why some of our ACEA qualified oils only claim API SL even though they pass all API SM engine performance requirements, the Phosphorus content is above the maximum level allowed for ILSAC grades.
There has been discussion about using diesel engine oils instead of passenger car engine oils. Some of these do currently contain higher levels of Phosphorus, ZDDP, than passenger car qualified to API SL or SM. They have higher Phosphorus to help minimise soot related wear. Future generations of these oils will also have Phosphorus limits and be lower over time for the same reasons as for passenger car engine oils. The higher level of Phosphorus is not a guarantee of satisfactory wear protection. As I said earlier, wear performance is related to the particular ZDDP being used. Also many of the diesel oils with higher Phosphorus also contain higher levels of detergent and dispersant which compete for surface area with the ZDDP which can reduce its effectiveness.

During the development of the current API SM engine tests, a high phosphorus diesel engine oil was run in a flat tappet, push rod engine test and it failed the wear requirements with worse results than most low Phosphorus passenger car oils.
In Australia we have many people rebuilding older vehicles and engines. Many of these people choose to put a modified cam into the engine when it is rebuilt. That is often the case even though they do not plan to get involved with Motorsport and the engine spends most of it life at low RPM. Modified cams with higher lift often require stronger or dual valve springs. All of these modifications increase load on the valve train and increase the likelihood of wear on cams and tappets.
The first few minutes of operation for new cam and tappets are very important.
Run-in is important for good long service life. Castrol have put considerable effort into understanding valve train lubrication. Research has shown one of the highest if not highest wear mode for a cam and tappets is while the engine is at idle. Running an engine at medium speed, say 2,000 to 4,000 rpm generates much less metal-to-metal contact between cam and tappet than at engine idle.
Also ZDDP is temperature activated so running the engine at low oil temperature also accelerates cam and tappet wear. Some years ago a race team contacted us after wearing out three camshafts during run-in on a dyno. They ran the oil at approx. 50°C. We recommended take the oil to 85°C, no more cam wear issues.

In summary most of the Castrol passenger car engine oils sold in Australia are still formulated to 0.10% Phosphorus maximum, the same as we have had for the last 20 years but higher than was used in the 50’s and 60’s. When running in new cams and tappets avoid idling as much as possible in the first 30 minutes to hour of operation. Make sure the cam and tappets are prelubed with Moly grease and oil. Try to keep engine oil temperature above 80°C. Driving the vehicle or running the engine under load achieves that most quickly.
The cam and tappets should be run-in by 250 to 500 km. Castrol Edge Sport 25w-50, previously Formula R 25w-50 and before that GP50, is specifically part of our performance range of engine oils for push rod, flat tappet engines. It has demonstrated excellent wear protection on radical cam profiles. Although rated API SG it incorporates the latest detergents and dispersants for good engine cleanliness, contains 0.10% Phosphorus and retains components for strong wear protection. The off-the-shelf product is widely used in competition engines.

If a full synthetic engine oil is preferred then our Castrol Edge 0W-40 or Edge Sport 10W-60 is recommended. Again these are formulated to 0.10% Phosphorus maximum and can be used with flat tappet followers with confidence the same as Edge Sport 25W-50.

Mobil 1 specify considerably higher ZDDP levels for flat tappet applications. Here are the values for comparison:

Castrol Edge Sport 10W-60 ZDDP 0.10% Phosphorus 0.09%
Castrol Edge 10W-60 ZDDP 0.11% Phosphorus 0.10%
Mobil 1 15W-50 (designed for flat tappets) ZDDP 0.13% Phosphorus 0.12%
Mobil 1 V-Twin 20W-50 (4T oil) ZDDP 0.17% Phosphorus 0.16% *

* Motorcycle (4T) oils are not subjected to the compulsory reduction of ZDDP and Ph.

[blue 464]

All good input. How does this SOC discount work, as there's a europarts near me and very handy.

if you lookat europarts web site as i did i recently got VR1 and antifreeze at 30% discount, the day after they increased the discount to 31%,typical!
derek

[Goldstar]

if you lookat europarts web site as i did i recently got VR1 and antifreeze at 30% discount, the day after they increased the discount to 31%,typical!
derek

Dammit another 23p down the drain........