Typical running Water temp - 420R - Duratec

[David_Long]

#25

The advice to move to 10w60 has been from several engine builders, all independently, and all from from their own experiences.

The first thing you learn quickly as an engine builder is that 'thick' oils and ''short' service intervals don't sell cars. The pressure on manufacturers to comply with ever increasing emission standards while keeping service intervals at a maximum has forced them to run very small clearance with thin oils. It is not that thin oils and long service interval are good for an engine - it only has to survive the process, it is ultimately about marketing.

By adding a margin to the oil performance you will will prolong life, particularly if you operate in the performance bracket. If you are in the 'tuned' bracket then it is really essential to get more than a few hours life.

The concept of thick oils clogging up in the filter and bypassing it, causing excessive oil pressure or flowing more slowly round the engine, is really nonsense in the practical world and is simply armchair theory. There is just no evidence that thicker oils are a cause for concern.  Further more, on engines that have non-graded bearings, or non-factory parts fitted (effectively all Caterhams), it really is essential to move to a thicker oil as it simply is not possible to replicate the grading and selection processes used by the factories. Your Caterham engine is not the equivalent of a 'factory fresh' Focus.

So where's my evidence for this? A few year back we decided to build a test engine to test oil grades and I had the oil analyzed for particles at each oil change. We went through all the available the grades from 10w60 to 5w30 - to cut a long story short, the thicker oils reduce wear, and the 5w30 oil test ending in a cam bearing failure on our engine. 10w60 showed about 10% of the particles of the 5W30 and on the RR at Northampton Motorsport we did a back to back on oils and saw about 3 BHP difference between the extremes.

 

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[ScottR400D]

#25 I would agree that those temperatures seem fine. The reason I asked was that doing the usual, possibly pointless, research on the www, you get all sorts of answers and I can't find a single authoritative source, eg an oil or engine manufacturer.  

I wouldn't argue with your comments about oil grade either; that fits with advice I've had and my own feelings. I'm running Millers Nanodrive CFS NT 5-40. The oil pressure is still very good, 3bar at idle and 5 or so at higher revs, when hot. When cold it will go up towards 6 bar easily. 

The point about how much oil flows where is interesting but I would have thought that if the pressure is maintained at or around the PRV setting then plenty should flow through the engine, you're just needlessly pumping too much oil around. Do you know what pressure the PRV is set at? 

One thing, even with the oil cooler in use, my oil runs at 70c, after cooling, in the tank so would be well into the 80-100c range in the sump. 
 

[Colin Heseltine]

ScottR400D,

No he did not actually give a optimum temperature, but he did show me some of the options for getting oil up to temp. e.g. Ford oil/water inter-cooler (similar in function to a Laminova - but completely different shape).  This (if I remember correctly) would need to fit between the oil filter and housing an be connected into the heater hose circuit.

Without fitting a sandwich plate with temp sender (and extra gauge or switch between water/oil) I have no way of knowing my oil temp.  I do have a infrared thermometer which I could possible use on the oil feed pipes and the oil cooler to get an idea.

It will be interesting to see what oil is used when it goes for its first service next week at the supplying dealer (Oakmere)

Colin.

[ScottR400D]

Thanks Colin. 

It's a simple job to fit a temperature sender into the oil tank, assuming a dry sump, and fit a switch and an extra couple of wires so that you can flick between water and oil temperature on the original water temp gauge. The tapping is already in the tank (or used to be) and the switch and wiring are easy to source. 

There is an argument that the temperature should be measured in the sump where it's hottest, which I accept but it's significantly more difficult to fit there. I use the gauge to tell me when I have a reasonable oil temperature and can start to use some revs and as a warning should it deviate from what I normally see. 
 

 

[aerobod - near CYYC]

Re #27, My PRV activates at just under 6 bar / 85PSI. With 0w40 oil that is hot and thrashed on the track (oil temps somewhat over 100C) the PRV activates at about 5000RPM and idle oil pressure is 2 bar.

[aerobod - near CYYC]

Re #29, Peter, my R400D triangular oil tank already had an oil temp sender fitted but not connected, as delivered by Caterham, likely due to the Stack instrument option making use of it when fitted (I have the conventional instruments). I just ran a wire back to the temp gauge switch that was added to the dash (looking at the wiring diagram the loom should have a connector already, but I couldn't find it).

[Colin Heseltine]

I must admit I have not looked closely at the oil tank.  Where is the tapping located (if present)(car is 2021 reg).  On my old car (1600K) I switched between oil and water temp using the existing water temp gauge and a switch.

Colin

[aerobod - near CYYC]

Re #32, Colin, my sender is in the bottom left of the front of the oil tank (2012 R400D):

[ScottR400D]

#31, hi James.

Yes, my tank had an unused sensor fitted in the same place as yours but it had on odd 'button' type connection onto which was squeezed a spade. I changed both senders for ones with an M5 (I think) threaded connector and fitted the cables with rings.

The first pic show how I redirected the cable from the loom to the switch and then ran a cable from each sensor to the switch.

The next shows the switch. Left is water, right oil.

[7 wonders of the world]

The oil temp should be taken at peak, the tank will show considerably lower especially if a cooler is employed. We had some new pieces made up for te Raceline DS to enable a sender to be fitted in the plate that retains the finger gauze filter in the trough.

Agree with all the the points re OE graded shells and, I also use 10w60 .

Rob I can only assume the stats your using are of a brand employing a softer spring or you plumbing it in an unorthodox manner, all the ones I've built employ either Ford or Mahle stats, a mix of oversize water pump pulley or under driven crank wet or DS and all maintain water temp.

The OE Modine cooler is fine of OE applications as it permits the oil to operate at the correct temp circa 100 degrees as the water temp is similar due to a higher rated stat, however used with the 82 stat to oil runs too cool and hence needs it own stat / cooler circuit.