Post Number: 58
|Posted on Tuesday, 09 May, 2017 - 10:04:
I'm currently using a 100% synthetic oil in my Cloud II and would like to know which oil I should use. For those in other countries the climate here in Brisbane is generally warm. Winter daytime temperatures of 16 - 20 C are normal. Summer temps get into the mid to high 30's. Am currently running Valvoline Synpower 10W-50 which does not come up on the automated Valvoline oil selector. They only show a mineral oil of weight 20W-50. Strangely, Mobil recommend Mobil 1 5W-50. It seems that here the cold start weighting does not need to be too light as it never gets really cold. I am particularly fond of the stable anti-sludging properties of synthetics. I've only recently got the car road registered, and I think my oil filter needs changing already although it has done maybe less than 12 hours running in the last 3 years since changing. The varnish which was baked onto the dipstick wiped off when I checked the oil recently after prolonged exposure to the synthetic. I suspect the previous owner never changed the oil for a very long time, and the detergents in the Valvoline have now done their job. I had an intermittent sticky lifter before the synthetic oil that came and went. It is still sticking sometimes. Shutoff and wait for 10 seconds, restart and it's gone which seems like some kind of vapour lock. It seems the more I run on the synthetic the quieter its becoming. Maybe the liberated contaiminants are making the oil more viscous. Oil pressure is OK when cold but slow to build when started hot and slow to drop away on engine shutoff. I have 2 aftermarket oil filters on the shelf from Post55, and maybe should change one this weekend to see if any change. Thoughts?
Post Number: 1807
|Posted on Tuesday, 09 May, 2017 - 10:27:
Yes change the filter this weekend.
I prefer the thicker oils so would not recommend Mobil 1
.you probably are not getting the synthetic oil hot enough to make the most of it.
I would use a cheaper oil and change it twice as often to get rid of condensation in the engine.
You will probably get lots of recommendations and they will all be right for different reasons. :D .
Post Number: 59
|Posted on Tuesday, 09 May, 2017 - 10:56:
Yes there are so many factors and I look forward to a multitude of responses. I brushed up on multigrade oil ratings and understanding thanks to several websites including Wikipedia, and checked the original RR multigrade recommendation which shows a lower viscosity hot oil weighting of 30. Maybe good for a new engine running 1960's oil, but how applicable to modern oil which can achieve better performance in every way and on a 20 yo rebuilt engine?
Post Number: 135
|Posted on Tuesday, 09 May, 2017 - 16:56:
I believe the important issue is ensuring the oil has sufficient zinc to reduce wear on the cam and tappets. Modern oils have reduced zinc. Surely we have a tribologist on the forum to clarify?
Post Number: 1525
|Posted on Wednesday, 10 May, 2017 - 08:33:
I think an inspection of the oil filter is warranted in your case.
When you remove the cartridge, hacksaw each end off and open up all the pleats and have a good look in the nooks and crannies.
I was alarmed at what appeared to be shiny chrome pieces when I inspected mine many years ago when I was trying to clean the engine from the inside with lots of driving & frequent oil changes.
I was also getting very small grit on my dipstick if I dipped the oil with the engine running.
These to appeared to be chrome.
Great I thought, camshaft!!!
What a shock I got when I opened up the filter paper to find all this shiny material in the pleats.
What I was seeing was reflections of my high intensity garage lighting in the oil, reflecting off these particles that made them shiny like chrome.
The particles were in fact small pieces of carbon.
After 12 months and 4 oil changes, this has now gone, and the odd time I now cut open the filter, it is clean.
My car now has 170,000 miles on the original engine, and I have only ran the engine oil the mechanic was using for the last 15 years before I purchased the car.
I don't believe in changing engine oil from one brand to another, or viscosity, if the car has been running on it for many years as my car has.
I run Penrith HPR30 which is a mineral oil with a higher zinc content, and not far off the original spec for the V8 since new.
I only run it, as that what has been now running in it for over 20 years.
The Shadow uses very little oil, and on our recent Federal rally to Canberra, and associated driving I did roughly 1,100kms and when I got home the oil was exactly half way between full and add.
It was just below full when we left.
Out of interest, the Shadow averaged 19L/100kms (14.8mpg) for the trip.
I do run Nulon long life coolant in the Shadow, ran at 50% of course & is changed every 2 years regardless of mileage.
I run only Nulon products in my 25 Chev, as I rebuilt everything, so have been using it from day one.
This includes engine, transmission, diff, grease, coolant & lead additive in the fuel.
My motto is when anyone asks me about servicing a car.
More frequent engine oil changes are required the less the car is driven. This is for low use or collector cars.
Of course never go over the manufacturers recommended intervals for cars used more frequently.
I call it a cheap insurance policy on the most expensive part of any car.
Post Number: 60
|Posted on Wednesday, 10 May, 2017 - 12:43:
Thank you Carl and Patrick. I had a read what was printed in Wikipedia about zinc dithiophosphate. the following is an extract from Wikipedia section on Motor oil:
"All the current gasoline categories (including the obsolete SH) have placed limitations on the phosphorus content for certain SAE viscosity grades (the xW-20, xW-30) due to the chemical poisoning that phosphorus has on catalytic converters. Phosphorus is a key anti-wear component in motor oil and is usually found in motor oil in the form of zinc dithiophosphate (ZDDP). Each new API category has placed successively lower phosphorus and zinc limits, and thus has created a controversial issue of obsolescent oils needed for older engines, especially engines with sliding (flat/cleave) tappets. API and ILSAC, which represents most of the world's major automobile/engine manufacturers, state API SM/ILSAC GF-4 is fully backwards compatible, and it is noted that one of the engine tests required for API SM, the Sequence IVA, is a sliding tappet design to test specifically for cam wear protection. Not everyone is in agreement with backwards compatibility, and in addition, there are special situations, such as "performance" engines or fully race built engines, where the engine protection requirements are above and beyond API/ILSAC requirements. Because of this, there are specialty oils out in the market place with higher than API allowed phosphorus levels. Most engines built before 1985 have the flat/cleave bearing style systems of construction, which is sensitive to reducing zinc and phosphorus. For example, in API SG rated oils, this was at the 1200-1300 ppm level for zinc and phosphorus, where the current SM is under 600 ppm. This reduction in anti-wear chemicals in oil has caused premature failures of camshafts and other high pressure bearings in many older automobiles and has been blamed for premature failure of the oil pump drive/cam position sensor gear that is meshed with camshaft gear in some modern engines."
So this raises the question of whether the API SM spec or the ILSAC GF-4 spec is sufficient for our older cars. It is a question of whether the test is fully representative of our cars. The last sentence above is not referenced I note, so it may just be here-say by the author or a third party. I suppose it's easy to play it safe like Patrick, and use an oil that allegedly contains a higher concentration of ZDDP, because oil producers generally describe when used the ZDDP content as "Full zinc" , or full ZDDP. Does that mean putting as much in as the current spec allows which could be one interpretation, or the amount permitted previously. Many of these spec changes and reductions in some compounds are mandatory if the oild is to be sold commercially, so perhaps no oil contains the same levels of zinc that they did at one time.
I don't know the answer, but I do know I need to remove my filter (and dissect it as suggested by Patrick) and agreed by Paul.
I thank everyone for their comments and interest so far.
Post Number: 1528
|Posted on Wednesday, 10 May, 2017 - 13:02:
Out of interest.
This is what I run in the 25 Chev.
Jean-Pierre 'JP' Hilbert
Post Number: 164
|Posted on Thursday, 18 May, 2017 - 07:51:
I like to use the oil of my choice together with this zinc additive:
This one is safe for catalytic converters. Some other zinc additives found on the market are not.
As for the used oil filter, you can send it off to specialised laboratories who make you a nice spectrometric analysis of all debris found inside. Costly though.
Post Number: 2300
|Posted on Friday, 19 May, 2017 - 00:21:
I have posted about this, at length, in the past and shall not bother again. See the thread entitled, Oil, ZDDP and Europe, on rollsroyceforums.com for what is my final effort.
If one wants to believe the API, SAE, and ILSAC then there is no question whatsoever that modern oils are not just suitable for our older engines, but superior to what was available when they were new.
Post Number: 1357
|Posted on Friday, 19 May, 2017 - 06:20:
I'm with you on this 100%.
I converted a car back to hydraulic tappets and other mods that should not work.
Modern oils no problem now.
The manufacture had failings in the fifties with hydraulic tappets so engines were modified back to solid type, the best oil at the time was found be the cause with nothing to compare with to-days oils.
Post Number: 1541
|Posted on Friday, 19 May, 2017 - 07:48:
Couldn't agree more Brian & Patrick.
Post Number: 144
|Posted on Wednesday, 24 May, 2017 - 21:16:
Would the above discussion on the best oil also apply to the six cylinder engine, I am wondering if I should switch to synthetic oil or just stick to the conventional oil I am currently using
Post Number: 2313
|Posted on Thursday, 25 May, 2017 - 07:49:
As far as I'm concerned the points I've tried to make are about motor oil itself and are relevant to any motor one might be running it in.
I think I made this point in the thread I posted the link to, but for the most part the benefit of synthetic over dino is longevity. Since most of us change our oil and filters in these cars far more frequently even than the original recommendations the longevity benefit goes out the window.
I don't think that using synthetic hurts anything, at least if you don't have leaks driving you crazy, but if you're changing your oil, say, every 3000 miles there's really nothing gained over contemporary dino oils.