620R Dry Sump Oil Change

[CtrMint]

Hi All,

Hope you're all safe and well.  I've decided to perform an oil change on my 620 after 500miles.  Mainly because I've been struggling to keep the temps up during running etc, so want to ensure that there hasn't been any fuel dilution etc.  I'm sending a fuel sample away for full analysis with The Oil Labs.

On my 420R I usually stick my pella pump down the dry sump tank and empty, you can reach the bottom of the tank with the tube.   On the 620 it appears to be baffled, so i can only get the extraction pipe half way.  Any recommendations?

I'm not keen to remove the connectors from the top of the tank as there seems to be a soft sealant used,  but it does seem the obvious approach as I believe a central internal structure runs to the bottom.   Your input would be appreciated.

 

[CtrMint]

Solved it in the end, took the connector off the top of the tank, the one which runs to the catch can.  Once off the pella pump hose goes to the bottom.  Simple, just didn't have the confidence to do it, took the plunge in the end after a lot of faffing.

[aerobod - near CYYC]

Do you have the Raceline dry sump with the finger filter, Mark? I find removing the finger filter on my R400 drains about 1 litre of oil in addition to the 5.5 litres in the tank. I know some people remove the oil line to the oil cooler instead to drain this oil, but I found that that method was a lot more effort due to spanner clearance.

[CtrMint]

Honestly I'm not sure which dry sump is on the car. I've not been under the car due to hassle jacking it up with the rear silencer.   Of course I will at some point.   Also when I removed the finger filter on the 420, I had excess oil run down towards the gearbox which created a mess, so I'm not doing that until a full filter change is done.  Today's task wasn't a full change I wanted to get as much engine oil out as possible to remove any notable fuel dilution.  I'm not saying there is any, I just don't know, the car was abnormally cold on the few days I got it out over winter, plus terrible fuel econ.  

I've been able to remove 5l exactly with the pump and added fresh 5w/50 Motul Sport back.  I just need to send the sample off now for analysis.

As an aside it looks like the IOM borders will remain closed until 2021, which means I can't get the car serviced until Spring 2021.  It's done 500 miles, so I'm pretty stuck now if I want to keep the service history all good.  I know it's a bit first world with everything going on, still frustrating having sunk 58K into the thing in Nov. IOM speed limits are down to 40mph too 

[7 wonders of the world]

I think you running temp issue goes back to your previous posts re thermostat and the lack of a correct by pass circuit, as I previously mentioned this will keep dropping the engine into its warm up map.

You need to get to the route of the problem.

[Mark w]

"this will keep dropping the engine into its warm up map".

When i looked at the 620 map settings  i found that the over-fueling warm up map had a fairly low cut off temperature .Ive now got an unlocked ECU and have not found the need to adjust from standard .

[CtrMint]

I don't want to be modifying a car with warranty for 2 years.  So to coin the phrase. "Test test test", let's see what the science supports.  Plus the car was bought mainly for track work, so the set up might be better for that.

[CtrMint]

I've got the oil report back.  Everything looks good.  

Viscosity was noted as lower than expect for the grade, I'm not sure if CC put 5w/50 in.  I'm also thinking the higher silicon levels might be due to the initial build with the dry sump etc, the oil hadn't been changed prior to the analysis.

Redacted image.

[Mark w]

When its cooler  ( below about 9 or 10 degrees ) blank the rad a bit,  otherwise you should be OK .In reality most Caterhams dont get driven much when its really cold . 

Fingers crossed for some good weather and the chance to get on track this summer .

 

[7 wonders of the world]

The high silcon reading wont be related to the RTV sealer used during the build, its more usually from fine naturally occurring particles that get through the air filter, or possibly assembly lube.

The fuel reading is unusual as the fuel dilution is normally expressed as a percentage on the ones I've seen....?

Was the sample taken for a hot engine or one that had been stood for some time..?

[ChrisC]

Looked at your video of the 620R sump on YouTube, noticed you have an oil cooler for the supercharger oil.  So be careful what section of the radiator you blank off, unless you are monitoring that as well.

[Mark w]

Looked at your video of the 620R sump on YouTube, noticed you have an oil cooler for the supercharger oil.  So be careful what section of the radiator you blank off, unless you are monitoring that as well.

The supercharger oil cooler is lower down nearer the oil cooler , blanking off some of the radiator doesnt effect this .

[7 wonders of the world]

You should not have to blank anything off at all  !

If the cooling and oil systems have been designed correctly ..?

Blanking radiators off is something best left to a Series 1 Land Rover..... !!

[Mark w]

Life to short to have these sort of discussions , im off 

 

[CtrMint]

The engine was warmed through to about 80, then left to cool a little, purely to make the extraction easier.  I cant comment on the fuel dilution report, the business seems like a reputable company, I've no reason to suspect or question their results.

 

[7 wonders of the world]

#15

I'm sure they are, but the dilution report shows a simple pass or fail test based on a 135 degree heat cycle, would be useful for you to understand what their threshold is, and how close or not you were to it, normally its set in the region of 1.5%.

If your at 1.3% for instant it would show a pass however its pretty low mileage oil, so shorty with more use, you could be into the realms of a fail,,,, if you see what I mean, were this 3000 mile oil it be a different story as the oil then could be deemed at the end of its life (not sure what service intervals CC recommend for the 620)  and therefore shows a different perspective.

[7 wonders of the world]

#14

 

So the first 620's were produced with no thermostat at all, then they fitted a stat but no bypass circuit so the stat is left in limbo do to its location in the return hose.

To worsen the situation there's no oil stat fitted either...

Do you really think its acceptable that you have to add bits of tape to the radiator in order to get any sort of running temperature...?

Having paid circa £60k for the car..... 

You should not have to do this - the car should have been engineered correctly. 

Aside from a longer warm up (no different to a tin top) my cars have all been out for winter blats and once warm all maintain their temp without issue.

 

 

 

[CtrMint]

There isn't an oil stat on the 420 either.

[7 wonders of the world]

or indeed on any model, however the other Duratec models do have a correct cooling system which I'm sure you've noticed behaves somewhat better than the 620.

[ScottR400D]

Reply to #19.

Hardly. Until a few years ago they ran 82c stats and now they run 105. 

They still run significantly fluctuating temperatures. My 2015 tends to run around 82 fan comes on when it’s a few degrees higher than that in traffic, so it never goes above 85. 

When you leave traffic and wind it up the temperature falls to 75 or so before creeping back up to 82. 

Cruising along it will stay at that but any time it’s wound up it will fall again. I had a 40 mile run out yesterday and even towards the end it would do this. 

With very high ambient or on track it eventually stops doing this quite so noticeably. 

Can’t really be said to be well designed, IMO, and I would suspect all the Duratecs are the same. 

 

[aerobod - near CYYC]

Certainly the R400D is optimized for thrashing at the track from a cooling system perspective. Most road cars can only run 20 minute sessions in summer temperatures here before overheating brakes, cooling systems or tyres. The R400D can run full one hour "happy hour" sessions without a break with a totally stable coolant and oil temperature. The only area I have found that suffers from overheating is the rear wheel hubs, getting hot enough to melt the retaining tabs on the plastic wheel centres.

[SM25T]

#21 ... worth checking the rear hub bearings have grease in them. Have known new builds shipped without proper grease lubrication in hub bearings.

[ScottR400D]

#21 I would agree with all of that, we certainly haven't had any concerns on track, it does run very happily at below 85. 

We haven't noticed any heat on the rear bearings but will bear that in mind. We’ve always been surprised by how cool, relatively speaking, everything stays. 

#22 I hadn’t heard of that. I was aware that the fronts often turn up with, arguably, not enough grease and checked them when the car was about a year old. One was fine, one barely greased. I know you don’t need that much but you need more than the thinnest smear. 

[aerobod - near CYYC]

#22, I did check that the first time I lost a plastic wheel centre on the track as I had to remove the rear axles to remove the diff anyway, they are well lubricated. The car has also done about 20,000km since then with no wheel bearing problems. It is really an issue of when the car is driven hard on the track with slicks on, the lack of cooling compared with the front wheels retains a lot of heat around the rear wheel arches. Now the 13" slick-shod track wheels are just run without the rear centre caps, but I still keep the front ones on for dust protection.

[7 wonders of the world]

Some track insist you remove the centre caps as they are known to make successful bids form freedom once things warm up.

I've lost a couple of rear ones after hard road use, I came to the same conclusion as Aerobod rear airflow my centres were the ones with metal claws in too...