Change Dry Sumped Duratec Oil

[Doc007]

Last time I attempted to change the oil on my (Cosworth) dry sumped Duratec I only got at 4l out. I siphoned the dry sump tank, removed the sump plug and oil filter and even disconnected the oil cooler hose (which yielded about 100ml!)
I looked in the How To guides and searched the archives but found nothing to explain why this might be.

Where does the oil hide???

I’m due an oil change and wondered if there was anyone in South London/Surrey who wouldn’t mind showing me the ropes. I’ve heard of Rally-Style changes but would not attempt such a thing on my own! I really would rather not blow my engine.

They would be plenty of tea and HobNobs by way of recompense or would be happy to travel to you (along with the aforementioned HobNobs).

Graeme

[Dan R]

I have a dry sumped Duratec and usually get 7ish litres out of it. 

I use a syphon for the dry sump tank as the drain plug is a peculiar size and shape and the thread is made of cheese!   I then take the regular oil filter off, and then remove the small finger filter that sits behind a small plastic cover on the nearside at the base of the engine where the sump would have been.  i usually get another litre or so out of there.  Ive never removed any pipes as ive always had a good volume of the old oil out.  

Im sure there are other methods and it may vary a little between engine designs.   Im a little too far otherwise id happily lend a hand. 

[Doc007]

Dan. I did the same as you apart from the finger filter. I don’t  think my Cosworth dry sump has one (see photos).

[KnifeySpoony]

I have a newer 420R and I use the same method as you and get about 6.4L out during a change. Just for another data point. But I'm not sure if my sump design is any different.

[Doc007]

I’d be interested to see a photo of the position of a Caterham dry sump drain plug if anyone has one. Do you think it’s possible that there’s a lot of oil that sits below the level of the drain plug? And perhaps some sort of curved pump would get the rest out? Or tilting the whole car to the passenger side??

[mph]

Premier Power used to have a really good article on their website about how to do this, but since they've shut up shop, most content has gone from the site. However, archive.org to the rescue…

https://web.archive.org/web/20230607112918/https://premierpowerengines.com/csr-oil-change-process/

[Doc007]

Thanks mph

[Doc007]

Reading the Premier Power guide it talks of the oil tank fitted to a CSR. And in point 3 talks of “remove the drain plug on the right hand side of the oil tank”. I have the 420-style triangular tank. There is a small grub screw on the left/front and the drain plug in the base purportedly made of cheese. And the bottom oil pipe. Which, if any, corresponds with the CSR right hand drain plug?

[Geoff Brown]

The R400/420 oil tank drain plug is to some degree 'fragile' but I would suggest that it is the threaded boss welded to the tank that is the 'cheese' hazard. As long as one is not ham fisted when tightening up & 'feels'' the tightness as it were all will be OK.

Another hurdle is the copper sealing washer which does wear slightly. If it has a slight wear ring caused by the plug the use of fine emery & a flat surface will remove.

Eleven years of oil changes, OK so far. Of course that has cursed the next oil change !

[Ralph45]

1 hour ago, Geoff Brown said:

The R400/420 oil tank drain plug is to some degree 'fragile' but I would suggest that it is the threaded boss welded to the tank that is the 'cheese' hazard. As long as one is not ham fisted when tightening up & 'feels'' the tightness as it were all will be OK.

Another hurdle is the copper sealing washer which does wear slightly. If it has a slight wear ring caused by the plug the use of fine emery & a flat surface will remove.

Eleven years of oil changes, OK so far. Of course that has cursed the next oil change !

Geoff, by any chance do you know the dimensions of the copper sealing washer used on the base of the oil tank? Having previously shied away from the method discussed and used a pump to empty the oil tank it is one that I would like to try.

Ralph

[aerobod - near CYYC]

2 hours ago, Ralph45 said:

Geoff, by any chance do you know the dimensions of the copper sealing washer used on the base of the oil tank? Having previously shied away from the method discussed and used a pump to empty the oil tank it is one that I would like to try.

Ralph

The copper drain plug washer is 10mm (3/8” will fit, too). 15Nm torque on that drain plug and a new washer each time has kept me away from the ‘cheese limit’.

[Ralph45]

Thank you James, much appreciate the help, copper washers on order.

Ralph

[22daz]

Doc, just a thought but how full are you running the dry sump tank? Mine is a Premier Power DS tank with a glass sight tube and it has to show as pretty full to get 6 litres out. You could quite easily run it 1.5 litres lower. 

It may be that you only had just over 4 litres in it?

22daz

[raw]

Having done a large number of  Duratec dry sump oil changes over the past year, I've never had any issues with the tank sump bolt. My advice is don't be ham fisted with it, nip it up (having ensured that the copper washer is in good condition) and feel the tightness - it doesn't need a torque wrench!

Cheers

Andrew