Numpty Dry sump oil qestion

[Tigger]

I've only had the car for a few months so still learning, so please excuse the simple questions.....

 

When draining and re-filling a 1.8K with a Caterham dry sump how much oil should expect I put in? The manual refers to 6 litres but how much can I expect to be left in the system after draining?

 

Final question..... The dry sump install has no dipstick can someone verify the level of the oil in the reservior?

 

Tig

 

 

 

 

[jimmyslr]

If you search back you'll see a variety of answers to this one. Personally, I take off the plate at the bottom of the bell housing tank, take off the filter and undo the oil pipe from the front rhs bottom of sump pan. I reckon I only get 4-4.5l out max. Some guys spin the oil pump, but I don't bother.

 

As for the level in the tank, I think anything from 9.5-10.5" from BOTTOM plate to top of oil. Varies by person/car it seems. Basically it comes up to the last baffle plate (right terminology?)you can see as you look down into the tank. A bit more generally preferable to a bit less as it will only get spat out into catch tank.

[Nifty]

Call me silly but I thought the K series was a closed system and didn't need a catch tank (i.e. it breaths back into the engine) *confused*

 

Keep off the straight and narrow 😬

 

Edited by - Nifty on 9 Oct 2005 19:29:55

[Myles]

Nifty - Can't remember seeing a *dry* sump system without a catchtank...

 

My ds experience and knowledge mostly comes from V7SLR, so I accept YMMV

 

...My understanding was that the overfill-and-let-it-find-it's-own-level method was the easiest way to go when you do a change. It'd then be sensible to check where the level ends up as a future reference for on-the-road checks.

 

Project Scope-Creep is live...

 

Alcester Racing 7's Equipe - 🙆🏻™

 

Alcester-Racing-Sevens.com

---

 

Edited by - Myles on 9 Oct 2005 20:53:58

[shn7]

Tigger,

 

I'm on my second K series DS'd Seven and have always done the oil change by removing the bottom (blue) plate from the belltankhousing and also removing the oil pipe from the sump. Then change the filter. This get out about 4-4.5l as already said. Then re-fill with the same amount. Warm the engine up and then switch off. Check the level in the tank straight away and top up to 9.5 - 10.5 inches above the bottom plate.

 

It's a good idea to make youself a dipstick with markings at these levels out of a piece of piano wire.

 

Overfilling will simply result in it finding it's own level by blowing the excess into the catch tank. Be careful not to overfill too much like I did once. The catch tank ain't thay big!!

 

Oh and it's only wet sump cars that don't need a catch tank IMHO.

 

Steve.

[Slipper man]

You will only get about 4 - 4 1/2 litres of oil back in normally, as the others have said. We all change our oilfar more than is really necessary, especially on the lower powered cars - the oil does not 'fatigue' within the time intervals most of us allow. On the very powerful cars like my R500, the problem is that the cars pump so much fuel that some of it gets into the oil (you can smell it quite clearly) and it is to get rid of that dilution that you are changing the oil regularly. As a result, I personally think it is overkill to do anything other than remove the plate at the bottom of the tank and re-fill. Always check the sediment to make sure there are no metal bits in it. Sure, you will still have some of the old oil there, but that is not a big problem, unless there are chunks of metal in the old oil, in which case you have other things to worry about.

 

The 'correct' way to measure the oil is with a long dipstick. The oil should be 9.75 inches from the base. When the oil is at that level, put in another 1/2 inch or so and go for a good thrash. Then (assuming some has gone into the catch tank) measure the level again immediately after switching the engine off and you have the right level for your car. Put a mark on the dip stick and you have the right reference point.

 

BTW - two other points:

1. Unless you are going on a circuit, the oil level can be quite a bit below (an inch or two) the mark without too much problem - the issue on circuits is the volume of oil getting too hot. On the road this won't happen and you wont ever be going fast enough for the oil pump to suck air.

2. When putting the 4 liters in after an oil change, put it directly into the tank, but when topping up, it is perfectly OK to fill through the cap on the rocker cover.

[Tigger]

Many thanks for the advice & tips. I'm slowly building a basic knowledge of the 7.

 

Tig

 

 

[Sheds Moderator]

My car has the early DS tank. When I forgot (early days...)that checking the level in an engine that has stood will give an artificially low reading and subsequently overfilled it, it didn't blow out into the catch tank. It leaked round the cap and when I later loosened the cap, oh Jesus. ☹️ I can therefore conclude that the breather does not vent the catch tank but the engine itself.

 

So, only check the level on a DS equipped engine that you have had running and then switched off. If you leave it standing and check the oil before a run then the oil will have drained out of the tank and into the sump. You then check the tank level and Jesus , it's nearly empty! Being a conscientious owner you add about 2 or 3 litres of oil till the tank is full and then when you start the engine all the oil in the sump returns to the tank and overflows all over the garage, the drive, the road, the underside of the car, etc. ☹️

 

Most of us will only do this once.

[Peter Carmichael]

Nifty,

 

You are mixing two ideas with your thoughts about the "closed system".

 

A dry sump setup runs a breather from the top of the dry sump tank always. You could in theory pipe this into your inlet tract, but this si frowned upon as oil mist causes detonation and with an overfilled DS it won't be a mist but a flood of liquid oil being actively pumped into your inlets.

 

The crankcase is frequently run sealed. So that the only passage for blow-by gasses out of the engine is out through the scavenge pump. There is a fatal flaw in the thinking behind a sealed dry sump system, which is that the pump's effectiveness at pumping is reduced ina vacuum. I much prefer to run a filtered (inhaling) breather in the head on my sry sumped engines. As an alternative, you can run a second breather from the top of the dry sump tank back to the head, which has a very similar effect, but reduces the net exhalations via the catch tank.

[Nifty]

Peter,

 

I don't think I have a clue what I'm referring to.

 

I'll need to look at someone's system to find out.

 

Keep off the straight and narrow 😬

[Casbar]

Before fitting my Pace system, the guys at Pace did say that their system on a K, is designed to work sealed! therefore, the pipe from the crank cover could go direct to the tank, and the tank breather could go to a second outlet on the cover, therefore, no catch tank!

 

Some people I believe run the system like this, but they experience a clucking sound from the engine

 

I went for the other option, breather tank, with pipe from cover to breather and pipe from sump tank to breather.

[Dirty Den]

Recommend getting one of the Hellier Performance dry sump plates as well - saves breaking the seal for the blue plate and makes the oil change a lot easier

 

Pics etc are on my site if you're interested...

 

Den

 

http://www.dens7.co.uk

[prs]

I looked at several options with this problem when fitting a CC dry sump. I eventually went for a vent pipe from the top of the coning tower to a catch tank, sealed one of the cam cover outlets off and used a small crankcase breather on the other, thus allowing the engine to breathe slightly. This also reduces the huge vacuum effect when you switch off and which can I believe result in the rear crank seal inverting itself.

 

Phil S7SVN

[Peter Carmichael]

Before fitting my Pace system, the guys at Pace did say that their system on a K, is designed to work sealed! therefore, the pipe from the crank cover could go direct to the tank, and the tank breather could go to a second outlet on the cover, therefore, no catch tank!

 

NO. This is factually wrong. The common use of the term "sealed dry sump system" does not mean what you have described above and what you have described CANNOT work. If there is no place for combustion gasses to exit the system, the system will pressurise and *oil will come out somewhere*. Probably blowing a seal out of the engine.

 

[shn7]

So Peter what does that common term mean?

 

Steve.

[Casbar]

Peter, you are probably right, I might have missunderstood Pace.

 

If both breathers on the cover were sealed, and only the tank was breathing to a catch tank, would that in effect be a sealed system !

 

 

 

 

[Peter Carmichael]

That's right. "Sealed DS" usually means the only passage for gasses out of the sealed engine is by being scavenged out by the pump, as described in my first post.

 

I still don't like that as an idea and I think experience has shown that the widely touted *extra power* from running sealed is overstated. Bald fact is that it reduces the effectiveness of scavenging. When I first put my 250bhp K on track I ran it sealed while datalogging the oil pressure. It showed a dip at 7900rpm, but with an open breather was fine to >9000rpm. This might be academic for many installations, but it set my mind at rest for extreme revs use.