engine oil spec '69 4.2

[Henkie]

Is it correct that a '69 4.2 needs 20W50 engine oil?

Thanks for your response.

[christopher storey]

Certainly 20/50 gives the best results . I have in the past used 15/40 which is easier to get, but it is a little on the light side when hot and results in rather higher oil consumption

[Simon P]

'Tis what I use in my 1969 4.2 - and is what was recommended by my engine builder.

Millers do it, but it's also freely available as Halfords Classic:



20 quid for 5 litres, or 30 quid for 10!

[iani]

I used Halfords Classic in my Stag, following advice I changed to Valvoline VR1 and saw a 5psi improvement in oil pressure across the temperature range, I now use VR1 in my S2.

Ian

[PeterCrespin]

Pressure isn't the be-all and end-all criterion - flow is important. Since most wear occurs on startup and all oils are orders of magnitude thinner at running temp than even a 5W-30 is cold, one can argue that it makes more sense to use a modern thin oil and avoid the wear.

Pete

[christopher storey]

I'm sorry, Peter, I cannot agree. Modern oils are for modern engines whose running clearances are radically smaller than engines designed 70 years ago. If you run thin oils in an XK, two things happen: 1. the oil film on the bearings , which actually provides the prevention of metal to metal contact, is negligible , and 2. the oil consumption increases significantly . I have never in fact tried the straight 30 which was the recommended lubricant when the XK was designed , ( and which we always used in my father's Jaguars in the 1950s ), but I suspect the results would not be very different from using 20/50 .

[Henkie]

Thanks guys. I'm going to use 20W40!

How many liters wil go in the engine? Is it 7?

[PeterCrespin]

Until pretty recently Chris I would have agreed with pretty much every word except the thin film bit. Recently I have read around the subject and have a different view now compared to that I've held for the last 40 years.

Chacun a son gout...

[christopher storey]

I didn't know you had gout along with your other troubles , P

[christopher storey]

Henkie : the correct quantity on a refill including filter is 14.5 pints ( 8.25 litres ) . Do not rely on the dipstick until you have filled the sump precisely, which will tell you whether the dipstick calibration is correct

I should perhaps say that the book says 15 pints ( 8.5 litres ) but the modern pundits such as David Marks all say 14.5 pints

[Henkie]

Henkie : the correct quantity on a refill including filter is 14.5 pints ( 8.25 litres ) . Do not rely on the dipstick until you have filled the sump precisely, which will tell you whether the dipstick calibration is correct. I should perhaps say that the book says 15 pints ( 8.5 litres ) but the modern pundits such as David Marks all say 14.5 pints

Reading your message for the second time..... you mentioned 8,5 liters and do NOT rely on the dipstick! What do you mean with that?

I had to fill up my engine with 10 liters before the dipstick reads full

[christopher storey]

The problem with the dipstick is threefold

1. People substitute non E type dipsticks which read incorrectly

2. On some dipsticks a collar is used which can slip , thus giving an incorrect datum for the dipstick to work from

3. Much the most common problem is that the dipstick gets bent by impact against the horizontal tray in the sump, and then reads grossly incorrectly

This is why you should check your initial level by filling the sump with 14.5 imperial pints /8.25 litres and then check your dipstick calibration against that

I should emphasise that these figures relate to 6 cylinder engines

[Henkie]

oke, thanks Christopher

[JJC]

5W30Wt in my 73 V12 for over 30 years. Works great, no leaks. Trick with engine oil is simply buy cheapest you can find, like Walmart in the United States, but change oil and filter often. I have a spin on filter, which I change every 1000 miles (easy..5 minutes) , and change oil every 3000 miles. Its a good practice to send oil samples out once in a while for analysis. Good to know whats going on inside the engine. Habit I picked up as an aircraft owner. Usually around 20 bucks US.

Happy motoring !

JC

[Moeregaard]

I've always used Castrol 20/50 in all of my old British iron. I stay away from the synthetics and the low-viscosity stuff because they have an annoying tendency to work their way out of the engine and onto the garage floor. What's just as important is to change the oil frequently, especially if the car is used for short trips. On the E-Types, I just followed the factory's recommended change intervals.

[Series1 Stu]

I have a spin on filter, which I change every 1000 miles (easy..5 minutes) , and change oil every 3000 miles.

JC

I see no benefit in changing the oil filter every 1000 miles but don't let that stop you, there's certainly no harm in it. However, I would recommend changing the oil every 3000 miles or annually, depending on which comes around soonest. Change oil and filter at the same time.

Regular oil analysis is a good idea.

Choice of oil is subjective and depends on the condition of the engine and the way it is used but a good 20/50 is probably best for our engines.

Regards

[JJC]

The reason I change filters at 1000 miles is two fold. #1 All filters are built with a bypass valve that sends oil back to the engine after a relatively short period of time, so the filter is doing nothing. As the filter has no monitor, my experience is that they are useless after 1600 to 1800 miles. So, and now reason #2, the spin on filters are only $4.00, so why not spin one off, and spin a fresh one on every 1000 miles or so. Since my oil maintenance is based on 1000 mile intervals, its easy to keep track. Another cheap way to keep your engine internals happy ! My test results indicate that my engine is a very content baby, with only slight, below normal wear. Happy Motoring !

John
1973 E-Type V-12.
Owned since new.
150000 New York City miles.

[SESH]

Always use 20W50 Valvoline VR1 Racing oil. As recommended to me by JD Classics.