what oil?

taffyjenks

taffyjenks

Member
Can anyone comment on what type of oil they use in their P6 2000 cars.So many differing opinions on the internet.Also can anyone tell me the name of the pipe that has two brass rings on which carries oil to the top of the engine? One end fastens to the casing where the plug to check the chain tensioner is and the other end bolts just below the oil filter.Mine split and emptied the oil all over the floor.
Thanks
Tony.
 
Timing chain oil feed pipe I think but could be wrong. I'd use a 20w50 oil aimed at classics. Millers and morris oils do them. For what its worth I use Halfords Classic. When I got the car the guy I bought it off was topping up with 5w40 fully synthetic.
 
Thanks people much appreciated.Three people have given me the same name so well happy.Re the oil I will shop around for that.
Cheers
Tony.
 
Halfords 2050 classic isn't up to scratch for the v8 due to low zddp content. . Is it ok for 4 pots?
 
Tony, I use Comma Classic 20w50, which I get for £10.50 from Culmac in Thornton for a 4.5 litre bottle. That fills the sump with a little bit to spare for top-ups. It's fine to use in the 4-cylinder, as I shall now attempt to explain!



We ran a technical article in Driving Force a few years ago on oil for P6's. The main points are that it is crucial to only use a quality mineral based oil (not synthetic, or semi), and to use the correct recommended grade - 20w50 for all P6 models: 4-cyls and V8s.

But there is slightly more to it than that. We discussed the implications of modern oils for 'flat-tappet' engines. In short, the chemical make-up of the oil you buy today differs a lot from what was available when your car was new, just like petrol has changed. Castrol GTX, for example, is not a thing like it was at the time and is best avoided for classic engines. One additive that oils had which has since been deleted (in the same way lead is now no longer present in petrol) is ZDDP (or Zinc dialkyldithiophosphates). It's an additive that assists lubrication in such a way to protect the cam lobes in engines with flat tappets. Modern engines either don't have flat tappets, or have harder material, but in any case, ZDDP is now rendered unnecessary for modern oil and has been removed.
Both the V8 and the 4-cylinder are flat tappet.

I haven't fully researched the meaning of this term, but if you take a bucket tappet out of a 4-pot you can clearly see the top area that comes into contact with the cam is flat:

DSC00741 by michaeljallen19, on Flickr
We could theorise all day about how this is a problem. The obvious is that dished tappets would spread the load over a greater surface area, but it could equally be related to material properties. But for whatever reason, classic cars engines with flat-tappets are generally believed to suffer premature cam and/or tappet wear. There is a whole industry built on this, and we could be cynical about that if we wanted. But several of this parish have experience of how quickly a Rover V8 can wear a camshaft down to nothing. Therefore, oils with the appropriate ZDDP additive, such as Millers Classic, Morris Golden Film or Valvoline VR1 are strongly recommended by the club as a sensible choice to help extend cam life.

In contrast to the V8, the 4-cylinder is not reported to suffer this same level of wear. Buckets can end up scuffed (probably due to poor oil filtration) which can accelerate wear on the cam, but common experience does not suggest the 2000/2200 is vulnerable to cam wear. I mic'd my cam when rebuilding the engine. It had done about 50k miles at the time, and the difference between each was negligible - not more than a thou.
The problem is that the camshafts are made of cast iron which is 'chilled' (coated in a harder metal in the mould), meaning that once the hard layer has been worn away, the softer iron underneath is free to be worn away like a bar of soap.

The bottom line being: if you've got a V8, best to use a classic grade oil for peace of mind. If you've got a 4-cyl, use classic grade if you want, but there is no obvious disadvantage to a quality mineral oil that we have found.

Hope that helps,
Michael
 
If both the V8 and 4 cylinder are classic flat tappet engines and classic flat tappet engines are susceptible to oil, such as GTX, with lower ZDDP content how come its ok to use it in a 4 pot but not in a V8? Also since most of our cars are at least 40 years old surely any damage would have already occurred by the numerous previous owners, particularly those who ran the cars before they achieved classic status, who used cheap supermarket special oils. I accept it's different if you have just rebuilt the engine. I find it hard to believe any oil for sale will damage these engines. Not changing the oil and filter regularly is far more likely to damage the engine.
 
pat180269 said:
If both the V8 and 4 cylinder are classic flat tappet engines and classic flat tappet engines are susceptible to oil, such as GTX, with lower ZDDP content how come its ok to use it in a 4 pot but not in a V8? Also since most of our cars are at least 40 years old surely any damage would have already occurred by the numerous previous owners, particularly those who ran the cars before they achieved classic status, who used cheap supermarket special oils. I accept it's different if you have just rebuilt the engine. I find it hard to believe any oil for sale will damage these engines. Not changing the oil and filter regularly is far more likely to damage the engine.
Click to expand...

Pat, I personally agree with you. What I posted above is a summary of the article we ran in Driving Force. I don't own a V8, so I don't have first experience of the cam wear, but I've been told by a number with first hand experience that it can be rather rapid. In my experience, and in that of those with many more years under their belt, the 4-cyl is fine.

But you make a good point about the "dark years" gap in the mid 80's to early 90's when these cars were just old bangers and not yet classics. I fully agree that this period would have been the dark ages, and any ownership that was likely to neglect or poorly maintain the car would have been during this time. When we on the mag team were having a bit of a technical discussion with various people regarding the 4-cyl engine bearing life expectancy for the last issue, we ran through all this. We basically concluded with the thought that, unless you can find a car with a verified life history and minimal miles (preferably owned by a vicar), and then inspect the bearing shells, then you can never wholly subscribe to the 'wobbly block' theory. If the vicar's car has uneven shell wear, it's weight behind the wobbly block argument. If not, you've got to look back to the dark years and ask "how religiously would oil/filter changed really have been maintained?" How many stories have you heard of people who've discovered a car in a garage and said:
Been stood for 20 years. Turned the key. Fired first time! :D
Click to expand...
Just think how dry and porous the bearing shells were at that point, and then think how much damage was done in the first 60 seconds.

So what we put in the article was "there are many potential causes, but what matters is that 4-cyls are known to have bearing wear 40-50k, so inspect yours and change if they're worn"
I think the same goes for the oils. "The V8 is known to wear its cam, so do what you can to help prevent that - and a good ZDDP oil is better than nothing - and tackle the bad stuff good and proper when it's off the road for a top end rebuilt."

At the end of the day, there's still an element of feeling in the dark. It's just a case of how cautious you want to be. Personally, I'm fine with my comma classic!

Michael
 
I've been using synthetic oil in my TCs for many years, with no ill effects. The rubbing wear that the zinc additives missing from modern oil formulations are meant to conquer is not an issue on the 4-cyl engine, for two reasons: the tappet block is always flooded in oil, so dry starts are avoided, and the tappet area is huge compared to the tappets in a cam in block engine.

Yours
Vern
 
The reason for the concerns on classic flat tappets is that, the tappets are supposed to rotate and infrequent oil changes causes build up of crap on them which will then stop them from rotating. The lack of rotation causes wear on the cam and on the tappet.
On a V8 you can see if the tappet isn't rotating because it will have a square pattern on it. Strangely enough, this will usually be the tappet which is or has gone solid and is making a noise.
On a 4 cylinder P6 infrequent oil changes usually leads to tensioner failure first but if not, you can find the tappet bucket when covered in a build up of crap again stops to rotate and you could end up breaking a valve spring.
The combination of flat tappets, crap build up and lack of rotation is the problem where wear is accelerated.
 
Just for reference, cam lobes cause the tappets to rotate as they have a slight leading edge angle to create the desired spin thus even wear characteristic's
 
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