How Do I/Check My K-Series Oil Level

==== Oil Capacities ====
  
||Standard Wet Sump:||5 litres||
||Standard Wet Sump with Oil / Air separator:||7.5 litres||
||Dry Sump (tank in Bellhousing) :||4.5 litres||
  
  
(Please note that oil capacities are approximate and because of the imperfect 
nature of all oil drainage methods the amount of oil needed to refill the 
engine may vary.  After an oil change, always check the oil level using the 
methods described below otherwise damage to your engine may result.)
  
==== Checking the Oil Level ====
  
===== Wet Sump =====
Run engine until oil is warm. Leave idling for 2 minutes on level 
ground.<br> **__//While still running//__**, dip using a sharp action to 
get a clean measurement. You can shutdown first as long as you dip immediately, 
but if you leave it for 30 seconds the oil drains from the head raising the oil 
level.  If you cannot read the oil level on the dipstick because the oil is 
very clean, press the dipstick against a clean piece of paper towel and the oil 
will show up very clearly on the paper.
  
There have been two dipticks.  The original Rover one was all yellow plastic 
and was modified by Caterham with a notch cut on it; the oil should be at the 
level of the notch.  The new caterham specific dipstick has a yellow plastic 
hatched section on the end of a metal dipstick; the oil level should be at the 
top of the hatched section when measured in this way.  Please note that the oil 
level is much higher than Rover ever intended for the engine and the oil level 
is very close to the opening of the dipstick tube in the sump.  If you overfill 
the engine it may not show up as being any higher on the dipstick, so it is 
more important that you check frequently and add small mounts of oil; thinking 
you can get away with throwing in some extra oil to keep you going between less 
frequent checks is not good for your engine.  The engine is non-standard on 
account of being fitted with a shallow sump.
  
====== Rationale (wet sump) ======
The original caterham instructions were to dip the engine at standstill.  When 
the Apollo tank started coming into use, it was noticed that the oil in the 
sump was very low when the car was running - it is this oil level that is doing 
the important job of keeping the pickup immersed, so there was obviously more 
variation between running and resting oil levels with an Apollo tank equipped 
car than without.  This was because the Apollo tank was draining back when the 
engine was not running giving a false high oil level reading.
  
It was also found that Rover fitted VVC engines with a different dipstick due 
to the amount of oil the VVC head retains. Caterham decided that, with all the 
different combinations, the simplest way was to check oil level with the engine 
running
  
===== Dry Sump =====
  
There have been two variations of Caterham dry sump system for the K.  The 
original used a purple scavenge pump with a large pulley.  The system 
introduced for the Superlight racers used a gold coloured pump running a 
smaller pulley.  Both systems used a special bellhousing containing an oil 
tank, but the later gold pump system introduced a de-aeration tower bolted to 
the top of the bellhousing tank (AKA "conning tower" with a different 
mode of operation to the Apollo tank).  The methods of checking oil levels are 
slightly different between the two dry sump setups.  The R500 system uses the 
same gold pump/conning tower system but uses magnesium castings; the R500 
system is sometimes fitted with a small Apollo tank.
  
The best practice is to establish a correct oil level by overfilling the system 
slightly so that some oil is vented to the catch tank after going for a drive 
with mixed amounts of high rev use, idling and cornering.  Once the oil level 
has settled so that no more is being vented to the catch tank when driven, the 
oil level is by definition at its optimum level.  It makes sense to measure the 
oil level physically with a dipstick once this correct level has been 
established so that you can replicate the oil level without unnecessarily 
wasting new oil by venting it straight into the catch tank.
  
The dipstick provided in the conning tower installation is generally useless 
(it tends to fall out of its cap after a few months use and it is very 
difficult to read the clean oil level on the green plastic.)  In order to get 
reliable dipstick readings you need to establish a routine.  Easiest is to 
follow a similar procedure as for wet sump engines: run the engine until it is 
warm, with warm oil (above 50 degrees centigrade); allow the engine to idle for 
2 minutes on level ground; shut down the engine and **__//immediately//__** dip 
the bellhousing tank using a long dipstick that reaches right to the bottom of 
the tank (most reliable method), taking care that the dipstick clears the oil 
pickup and does actually reach the bottom of the tank.
  
On a gold pump/conning tower equipped engine, the correct oil level is usually 
between 10 and 11 inches from the bottom of the tank.  On a purple 
pump/non-conning tower equipped engine, the oil level is usually an inch or so 
below the baffle plate you see when you remove the cap on top of the 
bellhousing tank.  No special measures need to be applied for an engine fitted 
with an Apollo tank in addition to a dry sump system.
  
====== Rationale (dry sump) ======
  
The scavenge pump always evacuates more volume from the engine than is being 
pumped in by the pressure pump.  It often pumps a mixture of oil and fumes, but 
if the scavenge pickup is immersed in oil it will quickly pump the sump dry to 
the point where it is sucking a mixture of oil and fumes again.  After idling 
with hot oil for a couple of minutes the greatest amount of oil will have been 
pumped into the bellhousing tank; the hot oil has the greatest chance to drain 
quickly from the head under the action of gravity down to the pickup.  After 
shutting down, there will be a slow seepage of oil back from the tank into the 
engine but it gives plenty of time to get a reliable dipstick reading of the 
oil level in the bellhousing tank.
  
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IndexK-Series[[IndexK-Series]]