Classic cars forum & vehicle restoration.

[Norseman]

[quote="emmerson"]
But the V8 was designed 50 years ago, so maybe it shouldn't have had synthetic anyway.[quote]

I've owned four RR Classics over the past 18 years & the general consensus amongst RV8 owners is that a quality mineral oil with high zinc is the best for two reasons (1) the oil pumps on these engines are not the most efficient & find synthetics too 'slippery' to get a grip on & (2) the flat tappet design benefits from a generous zddp content to reduce cam gear wear.
I tend to use products like Valvoline VR1, Penrite etc. (depending on the deals available at the time) as these state the zddp content whereas some other 'classic' oils do not.
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1987 classic Range Rover Vouge
1998 E39 523i SE sedan

A great many models have served me well since the 'sixties, all of them old & some even older than me.

[Ashley]

Synthetic oil is best for any engine and anyone who says otherwise is misguided.

I advise watching the various oil company videos on YouTube that dispel all the old wives tales from people determined not to spend the extra.

Cams and tappets need synthetic oil most in old engines.

Mobil 1 has numerous videos worth watching.

[emmerson]

[Bitumen Boy]

[Norseman]

I too disagree Ashley, the fact the oil companies produce the videos tells an old cynic like me all I need to know. I respect your opinion but will continue to use the grade of lubrication that a great many long-term RV8 owners & engine re-builders (both private & trade) put their faith in.
_________________
1987 classic Range Rover Vouge
1998 E39 523i SE sedan

A great many models have served me well since the 'sixties, all of them old & some even older than me.

[Ashley]

The facts are as follows.

1. Synthetic oil is thinner when cold and more quickly reaches where it’s needed than mineral.

2. Synthetic oil doesn’t dissolve in petrol so reduces bore and ring wear, which is a problem when the choke is out or the carbs flood.

3. Synthetic oil maintains viscosity to much higher temperatures and pressures, so might prevent a seizure in an overheating engine or maintain oil pressure when mineral oils won’t.

4. Synthetic oil clings to surfaces for longer so that an engine left for a long time will have better protection of cams, tappets, cylinder bores etc when you start it.

5. Synthetic oil can withstand high pressures so that cam and bore wear is reduced.


As I’ve already said, oil companies tend to recommend the same synthetic oils for older cars as they do for racing engines.


The reasons are.

1. Old cars tend to be undergeared, so a Morris Minor is doing 4,000 rpm at sixty and some moderns 2000 rpm at eighty.

2. Older cars have longer strokes and higher piston speeds too, so are much more highly stressed.

3. Older cars have less good camshaft and tappet design so wear more quickly. synthetic oil virtually eliminates wear.

About forty years ago I read a piece in a BMW bike owners magazine about the company’s testing of Mobil 1. They picked a car with sixty thousand miles on it, switched to Mobil 1, drove it to a million million miles and then stripped the engine. Everything was still within wear limits.

Subsequently numerous other car companies have published similar findings. Even Rolls-Royce recommended it for all their engines back to the Silver Ghost and Paul Wood of P&A Wood is using it in an Rotary engined WW1 plane he owns because it gives better protection and doesn’t dissolve with petrol. A problem with rotary engines.

The science is fact, proof that synthetic oil is best for your engine whatever you might think.

Obviously if you’re not bothered about the future or future owners, it doesn’t matter, but I use it in all my cars for the stated reasons.

As I said, you’ll find all this on YouTube though I actually phoned oil company chemists to make sure I’d understood correctly.

[Norseman]

I don't doubt your facts Ashley but perhaps you should bear in mind that my original reply to this thread concerned Emmerson's post who was running a RV8. These engines (ex GM/Buick) were designed in the late '50/early'60's so are not as ancient as those installed in cars you seem to be referring to. The RV8 is both over-square & low stressed (certainly in it's basic tune role) & can handle quite low oil pressure without detriment.
_________________
1987 classic Range Rover Vouge
1998 E39 523i SE sedan

A great many models have served me well since the 'sixties, all of them old & some even older than me.

[Ashley]

[Norseman]

[Ray White]

I am sure it can be proved that synthetic is better than mineral but please, please don't switch straight from mineral to synthetic with an engine full of sludge; especially where only a gauze strainer is used as a filter.

There are detergent free mineral oils available from Penrite etc. and these would be a safer bet until the engine is rebuilt and thoroughly cleaned; at which point a synthetic oil should reap the dividends that Ashley has described.

[Penman]

Hi
The garages I have used over the last 20 to 30yrs for my driving school cars always recommended Semi-synthetic.
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Bristols should always come in pairs.

Any 2 from:-
Straight 6
V8 V10

[emmerson]

[emmerson]

[Ashley]

[Ashley]