Dry Sump Oil - Quick Simple Queries!!

[bl0498]

Guys,

 

I am hoping to start my nice new 1600 K series supersport engine equipped with the Caterham bellhousing dry sump and high swirl tower tomorrow. (Yes Barry I have managed to get this far!!)

 

The Caterham manual indicates the dry sump setup needs 6 litres of oil straight into the bellhousing tank. Just added 4 litres via the swirl tower and it already reaches the high mark on the dipstick just below where the swirl tower attaches!!

 

So does the engine need 4 or 6 litres? If the latter where do I put the extra 2 litres - via the engine filler?? I was a bit concerned with putting all the oil in the bellhousing tank and none in the engine anyway - all that wear on initial engine turning whilst building oil pressure. Alternatively with 4 litres in the tank will the level drop rapidly when I start to turn it over on the starter thus allowing me space to add the remainder?

 

Many thanks,

 

Brian

[Nick G]

Brian, You'll find when you crank the engine over, that the oil level will drop dramatically. You should be able to add a bit then. BTW, I've found with my non-swirl tower set up, that it only takes 5l. Any more ends up in the catch tank after a few miles. I'd stick in 5l initially, then add in the extra a bit at a time and see if it stays in.

 

As for putting any in the engine, I wouldn't bother. It will only go straight to the sump and from there, be sucked out to the bell-tank. Crank over the engine with the immobiliser armed before starting it properly.

[paul jacobs]

I assume that by high swirl tower you mean an extension on the filler neck of the bell-tank.

 

What is the purpose of this higher neck, and what happens on the original low filler neck tanks that could be detrimental, other than only taking 5 l. of oil?

[Nick G]

Paul, as I understand it, the low top was standard until the VHPD came along. Then it was found that there were oil starvation problems (due to oil retention in the head ?), and so high flow-rate "gold" pump was fitted. However, this caused aeration problems with oil, so the swirl tower became standard fit on VHPD dry sump systems.

[Bob Corb]

Sounds like there still may be an oil aeration problem even with the new tower, is this the reason that VVC engines go t**ts up when dry sumped??

[fool on the hill]

as a complete novice with a dry sump engine can someone explain in very simple terms how you know you have enough oil on board?

 

Supplementary question-how long do you have to let the car idle (from cold) before being able to check the level?

any info much appreciated

[Peter Carmichael]

I have never heard of a VVC engine blowing up because of a dry sump system. It is difficult to see how a regulated delivery of oil could lead to an engine failure.

 

I have never heard of a VVC engine with a dry sump system.

 

Is it possible that the VVC plenum arrangement clashes with the dry sump scavenge pump and so they are incompatible?

[Nick Green]

FOTH, How much oil ? I assume we are talking the Caterham system here. I've found, as have others I know, that the limiting factor is when it starts being spat out to the catch tank. I don't know about other DS systems. "As much as the system will take" is the answer, I think.

 

As for level chacking, the Caterham advise is to do it with a warm, just stopped engine, before much oil has a chance to drain back to the sump. Which, thinking on from the previous paragraph, implies a more objective method of checking: With a low top DS system, use a piece of stick. Caterham recommend a notch 10" up, though I've found with my 5l limit that 9" is about spot on.

 

The high top system has a "proper" (ie built-in dip stick. Luxury.

[V7 SLR]

The reason for the high top is as previously described... due to a higher capacity pump the oil needed a swirl pot.

 

The capacity issue is a shade over 4 litres. Put about 4.5 litres in an keep emptying the catch tank until it stops filling up. Then you've got enough.

 

I've had one for over a year and this is the best advice I've had for it.

[bl0498]

Thanks guys - once cranking over the oil level dropped abruptly and I now have just over 5 litres in the bellhousing tank. Oh and the car started superbly - and once I had sorted out the two water leaks and one oil leak (dry sump pipe) no problems!! Oil pressure showing 5-6 bar on idle to warm.

 

On the swirl tower I was told that this was essential with the uprated gold pump to prevent oil loss to the catch tank and provide much better oil/air seperation. With the purple pump, which I have, its a nice to have...

 

Best Regards,

 

Brian

[Barry H]

Congratulations Brian - I'm expecting great things from you now!

 

When is your first competitive outing?

 

Have you ordered TB's yet?

 

Regards,

 

Barry

[paul jacobs]

On the subject of scavenge pumps et al, can anyone recomend a pump other than the ones supplied by the factory? If I understand it correctly, doesn't the engine use part of the inbuilt pump as well as the external one, like the old Vx supplied dry sump system, but most people ended up using a pace scavenge pump and ditching what was left of the inbuilt oil pump.

 

The other worry I have with the factory supplied kit is the drive belt. I believe that it is only grooved, with no teeth, is this such a good idea, and was it responsible for the self detonation of a couple of factory engines?

[Nick Green]

Paul, I don't know of any other K dry sump pump system. (Caterham's system has an additional scavenge pump, but continues to use the built-in oil pressure pump.) I believe Roger King has installed a xflow system on to a K-series. Perhaps he'll have some bright ideas ?

 

On the belt subject, the pump belt is V, not grooved. I thought the problems with the belt coming off on the Factory R500s and Peter C's engine was due to running arund the 9k revs mark and that the belt just couldn't stay on ? I think it depends how many revs you are planning to use. I don't think SLRs (non 500s) have the unshipping problem.

[Peter Carmichael]

The crankshaft driven pressure pump is a good thing to maintain. It cannot fail unless something very nasty happens to the rotor.

 

Belts have power ratings. Poly-vee belts are very effective at power transference. They self tighten, so tension is not critical with them. A toothed belt can additionally ensure that there is no slippage, which is necessary for cam timing, but needs to be set at the correct tension. A toothed belt won't be particularly clever for driving shock loads, because it can't allow any slip. A scavenge pump generates shock loads. Therefore a poly-vee belt could be considered a preferred solution for dry sump scavenge pumps.

 

The k-series dry sump poly-vee scavenge belt is marginally specced for the R500 engine (revs and power demands of the gold pump at 9200 rpm). A bigger poly-vee belt would be an excellent solution but would require modification to the spring-loaded tensioner arrangement also.

 

Any belt is a possible point of failure. This is a nuisance for an alternator belt, but is catastrophic for a scavenge pump belt. I am modiying the tensioner so that if the belt falls off or fails, I will get an early warning. I can then carry around a spare belt and be ready for most eventualities.

[V7 SLR]

I was never worried about my belt until you had your little problem Peter, so when you have satisfied yourself that your early warning system works OK, I would be very interested to see the design... if you don't mind.

 

Cheers.

[Nick Green]

While this thread has become a bit dead, I realised a few days ago I had given a little bit of duff info, which I don't like doing.

 

For the record, the DS scavenge pump belt is not a V as I said in my last post; it is indeed poly-v, as PC subsequently states. It has 2 grooves in it.

 

Edited by - nick green on 12 Mar 2001 18:11:12