Oil & Filter for Cosworth BDR HPC Caterham

[Big Al]

I recently picked up a Cosworth BDR HPC Caterham. As the car has been little used for a couple of years I would like to change the oil ASAP. Looking at the documents I have the oil was last changed Jan 01, about 1000 miles ago. Unfortunately I do not have the owners manual at this time, it is due to be posted to me by the previous owner. Can anyone recommend an oil for this car and what oil filter I should have. As far as I can tell it is standard HPC spec and has a Dry Sump.

 

I have changed the oil on plenty of cars before any thing special I need to be aware of with a dry sump? Any useful tips?

 

Previous owner was billed for 10 litres of oil at each change does this sound about right?

 

I plan to get the car checked over professionally in the near future but when we get the odd sunny day it is very tempting to take it out.

 

Big Al

(I'm not big and I'm not clever)

[Trevor Phillips]

The previous owner of my BDA always ran it on mineral oil. Remember, synthetics were only just coming on stream in the early 70's.

 

10 litres sounds about right, most tanks are 2 gallon plus you have a bit left in the sump and all your pipes & filter. Fill the filter before fitting. Take out the plugs and prime the system by turning it over on the starter for several minutes [not all in 1 go as your starter may become too hot]. If you have the newer Tilton Mk2 oil pump you can connect a power drill with flexible drive and a screwdriver bit into the rear shaft to crank it over and save the starter motor.

 

Usually, you fill to just below the top plate but you can only check the level once the oil is hot so don't overfill cold.

 

Racing pics and items for sale here

[Simos]

Hi Al,

although the engine design is not modern if it's been built/rebuilt lately then I believe you can treat it as a modern engine because it will have modern brearling and finishes etc.

Roger King has always advocated Mobil 1, not particularly because it is better than any other oil (though it might be) but because he has seen very few problems with it. That works for me. My dry sumped BDR has M1 15/50 in it. 5/40 would be more suited to lots of road work perhaps, I did try it once and it gave me lower oil pressures, which, while probably correct worried me so I went back to 15/50.

 

Cheers, Simon.

[Slipper man]

Different people have different views on this. John Minty, who is a BD specialist prefers to see Valvolene 20/50 racing oil, which has the benefit of being very cheap. He prefers to see the engine running the best type of oils available when it was built, which is why he doesn't like synthetics. I don't know how much of this is just prejidice, though.

 

What is certain is that older engines had wider tolerances and need thicker oil, so if you do use Mobil 1, you must use the Motorsport 15W/50 type.

[Bilbo]

Hi Al

 

I use Mobil 1 in fact it always seems happy with either version oil changes 3000 miles or 6 months. Bit OTT with Mobil 1 but a re-build is more expensive than the oil ❗ .

 

As others have said always top the filter up..... on any car. My oil filters under the carbs out of harms way.

 

Check oil after running the engine with a dry sump the oil tend to work its way back to the sump ❗

 

I check the oil level with a 2.5 foot ruler that I keep in the boot so it reads about 4.5 " that's not the true level, its as far as the ruler will go in. Just gives me a datum. Its a bit more than where it seems to end up after a VERY long run. Track days a bit more as ts going to be reving higher for longer. This assumes you have the big Caterham tank at the bottom of the passengers footwell, mine was bought 1991 ❗

 

Take the tank out and clean it when changing the oil. It gets a bit of crud at the bottom of the tank.

 

Stick just over a pint in the sump when doing a oil change, so the return pumps not dry too long on start up. Its amazing how much the lines and oil filter takes so check the level when the engines warm. Pull the plugs and spin it over until you get a few bar pressure then put them back. Also do this if the cars not run for a few weeks.

 

Well that's what I do.....

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension. Q 979 CGY