Baffling Vauxhall

[GordonW]

In anticipation of an engine refresh/upgrade I recently had an email conversation in which a respected engine specialist expressed the view, as a part of the dry sump not dry sump question, that a 'properly' baffled sump might help a lot. I'm guessing he meant junk the foam and substitute a fixed metal plate at the same height as the top of the foam which would be (part?) perforated but have a circular hole in the same position as the 'well' in the foam which would give pick up pipe access to the oil reservoir 'trapped' beneath by the baffle plate.

Is this a too simplistic interpretation of the concept? Would you still need the windage plate? Has anyone out there tried something similiar?

Any views on the worth of the idea as an economic means of stabilising oil pressure at a few not too demanding trackdays/sprints?

[oilyhands]

Proper baffling would involve some vertical baffles that surround the pickup and a horizontal one on the lee side of the engine.

 

Dave

[I reply to every thread]

and trapdoors - part of the problem with the Caterham VX installation re baffling is that the sump is pretty shallow anyway

[Paul Deslandes]

If you don't want to spend the money on a dry sump, and I can see why you might not given the cost and that you only do a small amount of track work, its worth considering an Apollo tank.

 

I confess I haven't done this myself but before I went dry sump I had previously installed an oil cooler which appeared to stop, or at least, reduce oil surge on fast corners and allowed the oil pressure to stay up much longer. I'm certain that, in reality, it was the increase in available oil capacity that was doing the trick rather than any cooling benefit. An Apollo tank will do the same thing, only better.

 

I agree with Aves that the Caterham sump is so shallow that its hard to see how effective baffling can be with such a small reserve of available oil.

 

There are a couple of cheap mods that you can make to the engine that do improve things quite a bit.

 

1) make sure that the oil pump pick-up pipe is clear of the bottom of the sump. Its possible for it to be so close that the small gap restricts the flow of oil up the pipe. You can sometimes see a witness mark on the floor of the casting if this is happening. If you remove the pipe you can cut/file four semicircular slots in the end of the pipe at 90deg to each other so that even if the end touches the sump, there's a gap for the oil to get through. Slots about 5mm deep is plenty. Also make sure that you change the foam baffle regularly. Even if it looks ok, modern oils seem to clog it very quickly so it may not be working efficiently and will be stopping the oil from getting back to the pump as fast as it needs to.

 

2) also worth doing is the SBD mod to the cam cover which involves removing and modifying the baffle plate which is there because the engine was designed to be mounted transversely in an FWD car. Details can be found here.

 

Paul

 

 

 

Edited by - Paul Deslandes on 16 Oct 2009 16:39:28

[Paul McKenzie]

My Caterham wet sump pan had a professionally modified windage plate/baffle system before I went to DS .........it didn't work ☹️

 

Paul

[GordonW]

Hi Guys, many thanks for all the replies.

My simplistic thinking on this is that if it stays wet sump then the efficiency of the system is governed by A. the effectiveness of the pipe in picking up oil and B. the plentiful availability of oil for the pipe to act on so;

 

Paul, much appreciate the extent of your post, I have already carried out the SBD cam cover mod and will delinately modify the end of the pick up pipe as you suggest at the earliest opportunity. I'll definately give the Apollo some thought too, I suspect this may well help keep more oil available.

 

Oily, are your baffle thoughts attachments to the sump pan base where the foam currently sits rather than the 'plate' above I described (or both)?

 

Aves, yes you are of course absolutely right about the shallow nature of the sump pan but here's what passes for my logic. Currently the foam may reasonably deter the oil at its level from slopping about too much but it has a comparatively small 'well' on which the pick up pipe can act and in the event that the oil moves away from the pipe area and the 'well' runs low I can't beleive that the foam allows the oil to refill the

'well' that quickly/easily. Surely if a volume of oil equivalent to the area occupied by the foam and captive by a plate above it is available to the pick up it has more chance of constant good supply than via the small well and volume displaced by the existing foam. The pan is always going to be shallow but creating a greater proportion of it that has more captive oil available to be picked up seems to be to be a reasonable objective. I realise that other baffles to reduce surge under braking may be a good idea too but I see that both SBD and Swindon have produced seemingly similiar mods for wet sumps. I guess it doesn,t necessarily mean they are right and certainly they both seem to operate on deeper sumps, although SBD not much so.

 

Paul Mc, your experience seems to confound my thinking, do you have any details of the mods you ran?

 

Thanks for all the input

Regards Gordon

[Paul McKenzie]

Can't remember details, but the windage plate was modded with baffles welded on, but no trapdoors. Maybe with trapdoors as well it might work, but as others have said the CC wet sump pan is probably too shallow. I'm sure that the deep sump solutions offered by SBD and Swindon will be well proven, and I have seen a Caterham installation with a modded deep sump before so they can fit but I don't know where it came from or how effective it was on track, as we changed it for a CC wet sump pan before it was tracked

 

Paul

[Paul Deslandes]

Just one further observation. I had a friend bring his Vx engined car over last year with seemingly low oil pressure. The initial thought was that it was the oil pressure sender at fault so we temporarily put on a mechanical gauge. It turned out that the electrical gauge was balls-on accurate! Removed sump, looked at foam baffle and thought 'that looks alright but we'll change it anyway'. Guess what? Oil pressure back up from 40'ish to 65psi.

 

The foam is bad news unless its been replaced recently and I would guess that it would just deteriorate with time, irrespective of whether the car has been run.

 

QED.