“Dry” Engine Oil Capacity ?

[44DHR]

This is the second associated post to my previous “Rear Sump leak concerns resolved !”.
This post relates to exactly how much engine oil should be used in a 6 cylinder E Type engine. In my previous post, I removed the sump and after taking out the baffles, everything was ready to refit. However, the Jaguar specification for engine oil capacity is 8.5 litres or 15 Imperial pints. I carefully refilled my sump with exactly 8.5 litres of oil and this barely registered on my dipstick ! I measured it using the bottom of the car door as horizontal to ensure the car was level.
This photo was taken after I drove 25 miles after the refill. Note the lovely clear oil !



I had cut a new mark on the dipstick after putting in 8.5 litres and had expected it to drop further once the oil filter had been filled, but bizarrely it shows above the mark. Irrespective of that, it is still way below the Jaguar hash markings. This is a new replacement dipstick and I still have the original one and when placed side by side they are identical and are not bent.







It makes me think by filling the sump to the Jaguar marks, potentially I have been running with far more oil than I needed and hence why I had developed a leak from my sump seal.

The other issue on capacity as that when the sump is drained, there must be quite a bit of engine oil, (half a litre ?), still retained in the sump webs and casting areas plus the sump basket, so perhaps the 8.5 litre figure is for a “normal” oil change where that oil would be retained, rather than a completely “dry” engine ?



Any thoughts and observations?
Regards,
Dave

[christopher storey]

One of the problems with the XK engine is that it can take at least 30 minutes from shutting the hot engine down for the sump to reach a true level and thus there is always a tendency for the hot level to be "under-read" . The capacity is so large by modern standards that in reality a small under or over read is probably of no functional significance. On my cars, after a change of oil and filter I run the engine for a short period, and then leave it overnight and then measure in the morning to get a true level . The other problem is the dipstick accuracy , affected as you have mentioned by inaccurate position of the collar, and also by use of the wrong dipstick, both of which are very common

[44DHR]

Hi Christopher,
The dipstick photo was taken this morning with engine stone cold, so plenty of time for the oil to settle. I marked the new cut on the dipstick with the engine cold before I set off on my first run out yesterday with 8.5 litres filled of lovely fresh clean 20/50 oil.
I showed the two dipsticks to verify the very valid points you mentioned.
Provided I maintain my oil pressures, I am reluctant to “top up” the oil, but as raised in my other post, perhaps a certain extra amount could be added to overcome the normal oil remaining in the sump casting and sump basket on a “normal” 8.5 litre oil change.
Cheers, Dave
Cheers,
Dave

[Gfhug]

And the words on top of the dipstick are wait one minute. Another conundrum!

Geoff

[abowie]

The only logical explanation for your problem is that somehow your dipsticks are measuring incorrectly.

My experience with a newly built engine is to add about 7.5l, run the engine to fill the oil filter, then top up using the dipstick.

I have not experienced gross inaccuracy with this; 8.5l is pretty much around the mark.

[Simonpfhc]

I concur with Andrew. Can’t explain your dipstick issues.

I’ve rebuilt many engines and always fill with 8.5lts of oil and then run the engine before measuring. It is important to never measure the oil level without first running the engine as oil is always deposited around various ‘pooling’ areas inside the block and head - usually about a litre.

[mgcjag]

Hi Dave...can you add some dimensions to your dipstick photos....has the top collar moved....does your stick sit right down onto the block....have s look at this dipstick thread and compare measurements....Steve viewtopic.php?f=5&t=19015&p=153856&hili ... th#p153856

[44DHR]

Thanks guys,
I will throughly check my dipstick dimensions and report back.
I did note that even after draining out the oil using the sump plug, once the sump was removed there was quite a bit of oil retained in the sump webs and casting areas, so that may affect the overall “new” fill on a car which had a “normal” change, rather than completely removing all traces of old oil as I did.
Cheers,
Dave

[44DHR]

Ok, so the dipstick has been measured with no major anomalies found.
From the “Factory Fit” section :-

1). From cap to top of hash marks....8 and 1/16th of an inch.
Mine is 7 and 15/16 inch, but I’m not to concerned on this dimension as it defines a “full marking”.
This is the long metal rule taped to the dipstick.





2). From cap to bottom of hash marks...a fraction under 8 and 11/16ths of an inch.
Mine is the 7 and 15/16 inch, plus 11/16 inch which equals a fraction under 8 and 11/16 inch as defined. This to me is the important cross reference as defined the “low” oil level.



3). From cap to bottom of dip stick 9 and 3/4 inches.
Mine is the 7 and 15/16 inch plus 1 and 13/16 inch which equals 9 and 3/4 inch as defined, so the dipstick is not short.



So hopefully this shows the dipstick which I have run in the car for over 20 years is within tolerance. Note also that I do not have a big felt washer under the dipstick cap which would raise the dipstick up higher, but the washer is fitted inside the cap. I was methodical in applying the 8 and a half litres of oil and remain convinced that around a half litre of oil remains within the bottom of the sump during a “normal” oil change in the sump casting webs and filter basket. I am going to add a further half a litre to account for that which will move my oil level nearer the “low” mark.
I have found some similar posts on-line of people filling with the 8.5 litres and having issues to get a “correct” reading to the dipstick and that does not include those who had bent or incorrect E Type dipsticks. I would definitely not want to overfill the oil and my oil pressure was just fine during my initial run out with the car.
I always empty the oil at the end of the summer’s use and refill with fresh oil so the car sits over the winter months with fresh oil in the sump. I will run it up and see where the level sits then after a “normal” oil change.
Still an interesting conundrum to be aware of perhaps as there is definitely a difference in oil fill required between an empty engine and one undergoing a routine oil change.

[DWW]

To be more concise with the results you should perform some further measuring on the block and sump to determine how far down the sump the dip stick really reaches and at what height in the sump you perceive the oil level to be. Also if you are in possession of one of those thin tape measures insert it down the stick tube and get a measure of the real level of oil......just a suggestion

[malcolm]

I know you said the car is level, but how sure are you? A few degrees makes a lot of difference. I laid a bubble rule on top of the engine with car in my garage to ensure it’s horizontal

[chrisfell]

On my dip stick the measurement from underside of the collar to tip is 10 inches precisely.

[44DHR]

Thanks Guys and I am continuing with this post as I have gathered more information from Jaguar sources and Rob Beere Racing and the one thing we all do on our cars is a regular oil change, so this additional information may be of interest.
In all my 20 years plus with the E Type I have never accurately measured the actual amount of oil that I put in during an oil change - just put in around 7 and 1/5 litres and after a run just topped it up when it was cold using the dipstick markings.
Reverting to Danny’s suggestion at post #10 above, I have done just that to get accurate measurements of the end of the dipstick to the sump floor. Before doing that, I took Malcolm’s advice at post 11 and ensured the engine was level. I had incorrectly been measuring the door base as horizontal, but in reality the engine sat slightly differently when a spirit level was used directly on it. This effectively had previously shown the engine down at the rear, so once measured correctly that slight angle did give me a slightly higher oil level.



I have a spare E Type engine here, so putting a brass rod down the dipstick hole, this measured 11 and 3/8 inch from the top of the dipstick hole to the base of the alloy sump. I also put this brass rod into my engine in the car with identical results as photo below - so no I don’t have an unusual sump !



By putting the brass rod alongside my dipstick, it shows there is 1 and 5/8 inch from the end of the 9 and 3/4 inch dipstick collar to the sump base. 9 and 3/4 inch is the “correct” length for this dipstick measurement. This also shows the oil level aligns with my dipstick oil level. My present oil level depth is 2 and 3/8 inches in the sump.





If we then extrapolate the depth of oil in the sump if using the dipstick markings by measuring back up the dipstick 1 and 1/2 inches to the midway point of the dipstick hashing, this gives us 1 and 5/8 inch plus 1 and 1/2 inch to total 3 and 1/8 inch depth of oil in the sump.

I then read the Jaguar Service Bulletin Number B.27 dated June 1963 which specifically cautions on not overfilling the sump at (iii)(a) and interestingly identifies the quantity of oil between the knurled (hatched) part of the dipstick is approximately 2 pints, (1.14 litres).





Also looking at the Jaguar E Type Service Manual, it specifically states the 8.5 litre is the Engine capacity on “Refill”.

I phoned Rob Beere Racing this morning and asked about oil capacity and they said that on a new build empty engine that they fill with two 5 litre oil cans. 10 litres equals 17.60 pints. He pointed out that on a normal engine fill - after draining from the sump plug, not only is there oil still held in the sump casting webs and basket, but oil in the head depressions. Interesting stuff ! He said they had successfully raced Jaguar E types with low oil levels, but the big issue becomes if the engine is overfilled as the crank webs are running in the oil and will seriously sap power.

So at least we have some reference points now and I for one will ensure my engine is level now - thanks Malcolm - and put in at least another half a litre of oil to account for my “dry” engine lacking pooled retained oil, but look to certainly not overfill the engine as there is some comfort in that the oil pump pick up is way into the bottom of the sump.

Regards,
Dave

[caveman]

[mgcjag]

All great info Dave.....Although it dosnt really explain why the oil level isnt in the cross hatch area....Steve

[DWW]

Well done Dave, glad you managed to get to the bottom of it all. Just remember, I am sure you know, those engines consume oil forgot what the rate is but I check oil and top up every few hundreds of miles.....

[chrisfell]

I use 10 litres every oil change. About 9 goes in to the empty sump, the the remaining 1 litre goes in to keep the engine topped up over the next 3000 miles.

Yes I do overfill the sump, 9 litres puts the oil level just above the hash marks. I was told to expect dire consequences as a result. After 80,000 miles I'm still waiting for these consequences to develop.

[mgcjag]

Hi Chris....i thought iv read other posts of yours where you say you have plenty of oil leaks and oil all over the underside of your car and its your "under body protection"... maybee becaus youve been overfilling

[chrisfell]

Unlikely. Over filing by a pint or even a litre will not force any seal or gasket joint to leak. It does not increase pressure in the crankcase. The biggest problem with overfilling is contact between oil and the crank webs. My overfilling is a long way short of that, even under acceleration or heavy braking. Once the engine is running several litres of oil is other than in the sump. You just have to listen to the amount of hot oil running back into the sump at shutoff to know this.

My engine leaks because it has been rebuilt on several occasions by fitters who shouldn't have been trusted with a roller skate. Mismatched and reused fasteners, undersize cotter pins, seriously imbalanced crank, rods and pistons, soft threads in the timing cover, as well as the rope seal. The gearbox also leaks, as does the differential. Can't blame those leaks on an overfilled sump.