Engine oil and zinc content

[Paul_S]

My motor has been worked on by DJR in a previous life and I spoke to Dave about what oil I should use.

One of the things he mentioned was getting one with decent zinc content (something to do with keeping the cam in good condition, but I don't know the details). At the time he said it was difficult to find oil like that in the UK and recommended some from the States.

But, I've just found this stuff and I think it fits the bill (for a good price!)

What do you reckon? Any advice would be appreciated

 

[Rob Gaskin]

Can't comment on that oil but 'Car Mechanics' mag this month (and I have bought it!) has a big section on oil.

Dave is a man of few words but worth listening to (the opposite to me).

 

[Paul_S]

<snip>

Dave is a man of few words but worth listening to (the opposite to me).

Erm, I beg to differ. I'd very happily sit in the pub with you and share a few pints!

 

[toopy]

One of the things he mentioned was getting one with decent zinc content (something to do with keeping the cam in good condition, but I don't know the details).

I use this https://www.millersoils-shop.co.uk/classic-sport-car-engine-oils

The ZDDP (zinc) is an additive that was used in older engines to minimise wear, notably the camshaft and rocker surfaces, it was gradually fazed out because it can damage catalytic converters.

 

[jonbills]

I use cheap synthetic oil from ECP and a bottle of zddp additive from ebay.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/183125078726
Although when I bought some they were selling in singles. Not sure I'd want ten!

 

[toopy]

forgot to add, i use the semi synthetic version, you could also use this mineral version as well https://www.millersoils-shop.co.uk/classic-pistoneeze-20w50-engine-oil

 

[Paul_S]

Ah, good stuff guys

So the zinc content must be important, but I've probably not read enough about it.

I can't vouch for the quality of the oil I linked to but it seems good value in comparison to buying oil and a zinc additive separately.

 

[jonbills]

Ah, good stuff guys

So the zinc content must be important, but I've probably not read enough about it.

I can't vouch for the quality of the oil I linked to but it seems good value in comparison to buying oil and a zinc additive separately.

Good price maybe, good value remains to be seen [emoji16]

 

[Paul_S]

Good price maybe, good value remains to be seen [emoji16]

Absolutely. I would like to know the base product.

I've always spent over the odds with oil for the 370Z and it's one of those things that are peace of mind but you never really know if you're being duped.

One thing with this oil is that they show stats to compare to others. But how does that actually compare to other products?

 

[jonbills]

I'm certainly not into branded oil. my only qualms are the 20/50 grade and so poor flow from cold. Well, that and the picture of pipe and flat cap cars.

 

[toopy]

I'm certainly not into branded oil. my only qualms are the 20/50 grade and so poor flow from cold. Well, that and the picture of pipe and flat cap cars.

Wasnt the recommended oil at the time a 15W 40 anyway, so not that much difference to the 20W 50

 

[jonbills]

I don't know tbh - don't know what was recommended back then, don't know how far 20/50 is from 15/40 in a real quantitative oil way.

I just remember from the olden days 20/50 was pretty viscous, that the bearings at cyl 6 are a long way from the oil pump for treacle and that modern synthetic 5/40 is more runny when cold and being synthetic stays in grade much better than mineral oil. And my oil takes about twice as long to get to 70 degrees as the water does.

I'm sure they're probably all fine as long as the oil is hot before any serious revs are used. I just feel better with the modern stuff.
But deffo use zddp for new or reground cam and rockers- I think there's an awful lot of pressure. Not sure it's quite so important for engines that have already done 100,000 miles.

 

[toopy]

I just remember from the olden days 20/50 was pretty viscous, that the bearings at cyl 6 are a long way from the oil pump for treacle and that modern synthetic 5/40 is more runny when cold and being synthetic stays in grade much better than mineral oil. And my oil takes about twice as long to get to 70 degrees as the water does.

I appreciate what your saying, but i wouldnt want to use anything thinner than a 10W as the tolerances in these engines are considerably wider than a modern engine, it might get round the engine quicker at start up, but if its too thin to properly lubricate the gap between components it may ultimately do more harm than good no?

The issue of oil staying in grade only really applies to forced induction engines and the extra heat as a result affecting the oil over time.

Ive read oil takes quite a bit longer to reach normal operating temperature as well, so an engine that has just reached optimum as far the water temp is concerned after a cold start, should still not be thrashed to the redline!

 

[moggy240]

I use castrol 10/40 and the same additive as Jon, might have to go halves on a 10 pack next time as I got mine as a single

 

[jonbills]

I appreciate what your saying, but i wouldnt want to use anything thinner than a 10W as the tolerances in these engines are considerably wider than a modern engine, it might get round the engine quicker at start up, but if its too thin to properly lubricate the gap between components it may ultimately do more harm than good no?

The issue of oil staying in grade only really applies to forced induction engines and the extra heat as a result affecting the oil over time.

Ive read oil takes quite a bit longer to reach normal operating temperature as well, so an engine that has just reached optimum as far the water temp is concerned after a cold start, should still not be thrashed to the redline!

I don't think I can go for that; 15/40 and 5/40 have the same viscosity at 100*, and they're both less viscous hot than they are cold so it can't be the case that 5/40 is dangerously thin when cold. 5/40 seems all upside to me [emoji4]