imp dry sump

[edgedj]

Hi Folks,

I'm seriously thinking of dry sumping my turbo imp engine, does anyone know of a supplier who can provide a kit to do the job? rough price info would be great too.

My reasons are:

leaky sump - very very leaky
turbo drain into sump works but is very short run and prone to failure in the long run
the drain from the sports head to B1 block is less than ideal
I can mount the 4.5kg oil forwards of the axle line and get better weight distribution.

Cheers
Dave

[SimonBenoy]

Stuart at Rodwell engineering has a dry sump kit on his website - don't know the cost though.

www.rodwellmotorsport.com

Cheers - Simon

[colin rooney]

I made up my dry sump system with help from robin human and it works well ,we used a flat sump from a formula 4 car with a lenght of box sextion welded in and the 2 return pipes i can supply pictures if needed ,a pace 3 stage pump on to the engine where the oil canister goes and remote oil filter with a 10lt oil tank ,My system is very close to what stuart makes as my mate took pictures of my set up and got stuart to copy it but stuarts sumps are a work of art compared to mine

col

[speeddemon]

Hi before you go down that route try Andy jones , hes just made an impressive wet sump and i can assure you it does the job. Whether you believe or not i know it to be fact that a dry sump will pinch power from your engine. Genuine Dyno print out proves this.

Ive seen this many times especially with the pace systems, on a type r Honda k20a it did the same. Hard to believe but very true.

I dont know whether Andy has any for sale yet but well worth a try

I think he has a site under shrigley engineering
Good luck

[bazzateer]

Nearly, it's Shrigley Engineering

http://www.shrigleyengineering.co.uk/

[edgedj]

thanks for all the input, I've been having a good think about this and to me a dry sump seems a leap too far at the moment. I've just ordered some AN-8 fittings to make a proper oil drain return to the sump. My basic idea of removing the weight of the oil and moving it forwards is pretty negligible in final effect when I consider the total extra weight of scavenge pump, swirl pot and piping etc.

I've now just got to figure out how to make that damned sump pan hold oil in!

Dave

[capriman]

Hi,

You could try Amber Racing as well, I have a fabricated wet sump by them. Its as light as a light thing with a lot more capacity than standard.

Cheers

Darren

[SimonBenoy]

Of course - Mr Shrigley! Yes, Andy runs a dry sump on his hrsr car - http://www.shrigleyengineering.co.uk

I also ran a dry sump for most of a season but have gone back to a large sump full of oil!

[benwick3]

Been running a self designed and built dry sump system on my race Clans for a considerable number of years with no problems in fact the 998 which was the original engine it was fitted to has now completed 5 season racing. As regards pinching power forget it. Not my experience and I believe I have been running a dry sump successfully on an Imp engine longer than anyone on this forum.

I also have a wet sump system that has proved very reliable under competition use but even so I would not go back to using it. I believe the worst enemy for an Imp engine used in anger in competition, particularly racing, is the accepted standard big sump. This allows the oil to flow away from the standard pickup, particularly under braking. My answer for a wet sump is to provide additional capacity by deepening the existing sump by 2 inches, retain the exising sump base as a horizontal baffle and extend the oil pickup through the base to sit in the bottom extension.

Pete Richards

[ibbo]

you say the sump is leaking you sure its not weeping out past the rear oil scroll

[edgedj]

it's a B1 block, so there is a proper rubber seal and it's in good nick. Problem is, I have in the past jacked the car up by the sump...

[Clive Brown]

FWIW, I built a wet sump design which was fully baffled but picked up the oil from the back (flywheel) end of the engine with the motor 'right way round'. What causes the problem with a conventional set-up is that oil surges forward away from the pick-up under braking, and then when you nail the throttle out of the corner, it runs an end.

Enderby's Karmann Ghia used the Imp motor in the middle and upright, and because the spigot shaft of a Hewland is below the driveshaft line as opposed to above it with an Imp gearbox, we couldn't make a wet sump work (too shallow), so I dry-sumped it using a twin-scavenge Pace pump, which worked very well. The sump was, though, virtually flat, with a channel just deep enough to hold the fittings for the scavenge channel hanging below it.

The Pace pump obviously took more horsepower to drive than the standard Imp pump, and the system was as a whole heavier than a wet sump, but against that, as the sump usually ran dry, there was no loss of power through the crankshaft windage that you get with a wet sump system.

If anyone is interested, I still have a number of the special wet sumps in store, but you would have to make your own pick up to fit the standard Imp oil pump base! Bits available from the Plumber's Merchants, if they still have Imperial fittings....

[benwick3]

For details of my dry sump take a look in theTechnical Album section of the Gallery. Under engines and engine bays there is a collection of images labelled race engine which show it. There are also some good pictures of Si Trickett's baffled wet sump which uses the same principle as I outlined in my previous post.

Pete Richards

[skamanfrank]

1825

3350

1231

4025

3108

1473

1210

1299

[edgedj]

I don't dispute what you lot are saying, buuuut doesn't the imp pickup face forwards and hence face into the direction of the oil surge under braking. I'd have though the problem with an imp setup would be under power not braking. Since most brakes out perform engines by at least 2/3:1, it makes sense to favour pickup under braking (i.e. the std imp setup). I've never noticed the light coming on under any conditions, but then again I haven't raced yet

One suggestion, couldn't a flap be fitted which would close under braking with the surge of oil forwards and prevent it's exit?

[bazzateer]

I don't dispute what you lot are saying, buuuut doesn't the imp pickup face forwards and hence face into the direction of the oil surge under braking. ?

If the pick-up faces forwards then upon braking the oil will surge forwards, so the pick-up would need to face the oil, I.e. backwards. Or have I got it all ar*e about face?

[skamanfrank]

FWIW, I built a wet sump design which was fully baffled but picked up the oil from the back (flywheel) end of the engine with the motor 'right way round'. What causes the problem with a conventional set-up is that oil surges forward away from the pick-up under braking, and then when you nail the throttle out of the corner, it runs an end.

If anyone is interested, I still have a number of the special wet sumps in store, but you would have to make your own pick up to fit the standard Imp oil pump base! Bits available from the Plumber's Merchants, if they still have Imperial fittings....

[bazzateer]

Yeah,

It needs to be positioned at the front, to collect the oil as it surges to the front. But as far as the direction it faces, surely it needs to face into the surge?

[Lotus-e-Clan]

Eric (Pimpdriver) during sprints found oil surge problems under braking when using the commonly available full length sump that has "return" holes in the vertical partition.

The problem is that some full length designs slow up the oil surge away from the pick-up using a vertical partition with holes to allow oil return, but once the oil has made it's way through the holes when traveling down hill / under braking it can't return quickly enough to the pick-up when going uphill / under acceleration.

And also consider that at high rpm (10krpm) using a high capacity pump with a high pressure relief setting, the rate at which oil leaves the sump can near 1 litre per second, so rapid oil return to the sump should not be overlooked.

Similarly, those designing full length horizontal partitions need to carefully consider oil return to the pick-up when facing up or down hill combined with braking and acceleration at high rpm. I've seen designs on this forum that would effectively trap a large volume of "return" oil at the flywheel end and above the partition when going down hill and under braking with little chance of a quick return to the sump. An extension to the oil return gallery below the partition may help a little but the oil escape from the crank bearings would be trapped....and btw, would swamp crank rotation somewhat too.

Best to use deeper or wider half length std sump designed with a low level horizontal partition, deeper as PR suggests, or wider like Mike Hannas design.

Also if your oil cooling is tip-top and your oil return has been properly thought-out, you don't need a large volume of oil. OK it takes longer to warm-up for sure (and that brings it's own problems), but once it does overheat in a fully heat soaked engine, you just have a large volume of overheated oil that adds weight to your outfit.

And talking of oil temperatures...you need to monitor them at the sump and after the oil cooler to see the full picture... and I reckon overheated oil at bearing level is probably at least equally to blame for bearing damage as momentary oil surge and if you combine the two then you've got no chance!

[edgedj]

very interesting stuff, I'm running a turbo on a sports cam so have a max rpm of 7.5k, also I have a modine oil/water heat exchanger and have a water cooled turbo housing to keep my oil in good nick. So I think I'm largely out of the group at risk form oil problems anyway, but thinking about the other problems mentioned here, wouldn't you guys be better limiting the amount of oil drawn at 10kprm rather than working out how to get that oil back to the sump. I imagine a large amount of the oil is hammering against the pressure relief valve above the oil filter and being returned down.

I do know one thing though and that's the fact that I know *nothing* compared with all those who have been studying this problem since the 1960's! If there were a simple decent answer, it would already have been thought of...

Dave

[bks974c]

This topic has got me thinking about my own sump baffle paticularly downhill braking surge and return to sump.



Due to an issue with the new HE oil pump the sump is off and so its still easy to modify the baffle.

The idea I'm toying with is to put 2 rectangular slots whose lower edge is at or just above the normal oil level.
This would still reduce the dreaded surge on LH bends but allow ample return to the sump side when the oil level
on the engine side is high dealing with the issue Peter K raised.



Or am I missing something ?

Scott

[cov_climax]

i had a play with deep, standard length, sumps about 2 years ago, not done much testing since, but puics are in this thread:

http://www.theimpclub.co.uk/viewtopic.p ... a&start=40

still can't get to the bottom of things, main reason for doing the sump was erratic oil pressure, which i'm still not much further forward on - had the relief valve out so many times now and I running out of mods/ideas.......

[bks974c]

I like the idea of deep sump but as the car is intended for rallying not really an option, and probably why Mike Hanna
would have gone the wide way.

Scott

[Mike Hanna]

Hi all. I developed the sump with a side chamber for several reasons. I would never lower the bottom of the pan as it makes it very vulnerable to grounding. My race car is so low at the rear that the drive shaft knuckles hit the inner arch/chassis rail above going down the first corner (Paddock hill bend??)at Brands Hatch so my standard depth pan must have been close to the ground. And some of the track side kerbs are quite high and rough!! My sump could also be used for rallying or hill climbing. Mike

[Adrian]

I can vouch for the quality of Mikes sump I am running one at the moment, after changing over from the Catrol R to Valvolene 20/50 ran it all last year and works great and do not see a need for the expense of a dry sump.
In fact Mike I keep meaning to ask can you make me another for my new engine

Cheers
Adrian

[Lotus-e-Clan]

This topic has got me thinking about my own sump baffle paticularly downhill braking surge and return to sump.

Scott assuming you're using a std half sump, I think you will only need to slot/drill more holes at the flywheel end to get a decent return on braking/downhill. The rectangular hole where the oil pump sticks through is all you need for acceleration/uphill oil return.

Also need to make sure the dipstick is well-sealed or the windage/crank disturbed oil above the baffle will want to escape through the dipstick tube at high revs.

[benwick3]

For some time I've considered that a well designed wet sump will work with no problems particularly where grip levels are not too high. I think a good example is the Historic Dunlop tyres used by the race Imps which aren't known as teflon tyres for no reason. The problem of surge becomes more of a problem with the higher grip levels of slicks as used by myself and Colin Rooney when I believe, and Colin agrees from his comments, that a dry sump is well worth the additional cost. Similarly, the additional grip offered by the modern semi-slick tyre, i.e. Yokohama AO48R, particularly when used to their full potential, also results in a situation where a dry sump is preferable. I saw this happen in the Roadsports Series when a fellow competitor only started having oil surge problems as his lap times reduced due to him using his Yokos to their limit.

Pete Richards

[bks974c]

Modified baffle as previous post with a couple of changes instead of cutting a slot above the oil pick up I folded it over
to provide additional prevention to surge.

The idea was to allow oil to to return to the sump side when oil was above maximum level then I started to think what happens
if the oil level dropped too much oil would still sit on the wrong side so added a couple of extra holes. Most of the oil will return
to the sump via the timing case hole. The flap above the oil pick up may direct the oil surge back towards the pick up.

All back together now, will have to wait now and see if it works.






Scott

[Lotus-e-Clan]

Not dissimilar in principle to my prototype version ....





...although this prototype has been modified....the flap under the oil pump body is now bent downwards to allow more crankcase oil back the the sump...found to be necessary after a road test revealed the uphill / acceleration / high rev problem!!

The main baffle acts like an umbrella over the pick-up allowing oil to return down the sides (plenty of clearance inside the sump) but keeps most oil in the pick-up area under the umbrella on a long left.

[Mike Hanna]

I can vouch for the quality of Mikes sump I am running one at the moment, after changing over from the Catrol R to Valvolene 20/50 ran it all last year and works great and do not see a need for the expense of a dry sump.
In fact Mike I keep meaning to ask can you make me another for my new engine

Cheers
Adrian

Hi Adrian. Thanks for the glowing endorsement. I presume you are racing at Silverstone on March 28 so I shall do one and bring it with me for you. If you could bring me a standard sump and oil pump end plate/pipe in exchange that would be great as my stock of parts is getting low. Cheers. Mike