Sump Guard - Anyone Interested

[Tony C]

Good thinking 😬

[mahatma]

I think you would want something soft enough to take as much of the energy as possible from the impact and not transfer it to the sump itself but tough enough not to tear too easily.

 

I would look at the sump guard as a consumable, a replaceable outer cover for your expensive cast sump.

 

A guess would suggest that 5mm of aluminium would be OK.

 

Andy

[Tony C]

One must wonder if you actually read Nifty's post 😬

 

A 5mm thick guard plus clearance from the sump will increase likelyhood of a strike

 

I think Nifty's right - what we need to do is Rick O'Shea 😬

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[mahatma]

Tony,

 

I read Nifty's post but without wishing to cause offence, it isn't necessarily sound advice.

 

If you use a sump guard, you're going to have to accept that the ground clearance will be reduced ... FACT. Now, do you want the ground clearance reduced and something between the ground and sump that will absorb some of the energy ... or simply transfer it all ?

 

What you need to do is determine the methods of failure. Is the aluminium sump;

 

1) cracking do to impact loading

2) Being ground away over time and creating a perforation?

 

If it's the answer is (1), you need to absorb the energy somehow ... if it's (2) you need to protect the casting with something more durable.

 

I suspect the major cause is (1) ... but I have no basis for that. Anyway, I don't need one ... so i'll leave it to you guys. 😬

 

Andy

[Nifty]

Andy,

 

It is both:

 

Option 2 occurs with most sumps but rarely to the extent that they fail before replacement.

 

Option 1 is the usual reason for failure and the need for protection.

 

The cast ali sump in itself is not what we are really concerned about, it is the possible engine damage due to oil loss that is the major financial worry.

I would agree that the guard may be considered as a consumable but it may not be much different in cost to a new sump if one goes down the harder material root. (Sump is £220 + VAT from CC..or certainly was a fortnight ago *mad*).

 

Further to this, in my case, the engine mounts tore and the exhaust then damaged my sideskin (a much more painful experience since they were brand new, powdercoated, freshly painted and Armourfended *thumbdown* 🙆🏻 ).

 

I think if you have a "skidplate"/sumpguard made of strong material fixed to the engine mount bolts then this will allow the car to ride over the bump/catseye without forcing the engine up on it's mounts, if it does come in contact with the sump (due to a close fit to minimise lose of ground clearance) the harder matertial will spread the load over the sump casing and will also wear better under the abrasion of the road.

 

It is my opinion that aluminium will not be strong enough to serve this purpose without be excessively thick.

When cleaning bits of aluminium with a scrapper blade it is very easy to dig into it...a bit of rough road at 60 mph will do considerably more damage.

 

Nothing is going to absorb all the energy of a 7 doing 60 mph down a road and hitting a bit of solid tarmac, or the steel casing of a catseye, sufficiently to prevent the sump being damaged.

The need is to deflect the impact away from the front of the sump and the only way to do this is to allow the car to ride over the obstacle and spread any load.

 

Stainless or titanium plate will be strong enough that it will allow this...I have my doubts about aluminium which will suffer from considerably more local deformation and therefore allow a localised impact on the front of the sump...objective defeated.

 

Aluminium needs to get pretty thick before it is strong enough to prevent me from bending or denting it with human flesh...I think the road travelling at 60 mph may be a little tougher than me.......may be *tongue*

 

Keep off the straight and narrow 😬

[SLR No.77]

Just a thought .....................

 

.............. what about an arrangement of "fingers" in a hard plastic type material that when fitted and attached like a grid, can slot between the fins of a K-series sump (I can't comment about the zetec sump as I have no knowledge of it). The front section would be sloping in such a way that the engine assembly would slide upwards and over the fouling object. The insert section could be flush with the fins or stand proud a litlle, but ground clearance could be virtually as good as without it 🤔 Material type would be similar to knee-sliders used by bikers?

 

Stu.

 

[mahatma]

Nifty,

 

I think I agree with your post in principle, but it may be worth considering a couple of points when designing a guard;

 

Further to this, in my case, the engine mounts tore and the exhaust then damaged my sideskin (a much more painful experience since they were brand new, powdercoated, freshly painted and Armourfended ).

 

I think if you have a "skidplate"/sumpguard made of strong material fixed to the engine mount bolts then this will allow the car to ride over the bump/catseye without forcing the engine up on it's mounts, if it does come in contact with the sump (due to a close fit to minimise lose of ground clearance) the harder matertial will spread the load over the sump casing and will also wear better under the abrasion of the road.

---

 

Will this not transmit almost all of the energy to the mounts ? Or if the steel/titanium bends, just load up the sump locally ... resulting in a similar scenario to if it weren't there?

 

It is my opinion that aluminium will not be strong enough to serve this purpose without be excessively thick.

When cleaning bits of aluminium with a scrapper blade it is very easy to dig into it...a bit of rough road at 60 mph will do considerably more damage.

---

 

Is this cast aluminium or rolled sheet ? They can behave quote differently to various loading situations.

 

Nothing is going to absorb all the energy of a 7 doing 60 mph down a road and hitting a bit of solid tarmac, or the steel casing of a catseye, sufficiently to prevent the sump being damaged.

The need is to deflect the impact away from the front of the sump and the only way to do this is to allow the car to ride over the obstacle and spread any load.

---

 

You don't need to absorb all of the load, just enough to prevent damage to the sump or engine mounts.

 

Stainless or titanium plate will be strong enough that it will allow this...I have my doubts about aluminium which will suffer from considerably more local deformation and therefore allow a localised impact on the front of the sump...objective defeated.

 

Not quite, the ali may have deformed enough to prevent further damage ... broken engine mount/sudden oil loss through holed sump.

 

Aluminium needs to get pretty thick before it is strong enough to prevent me from bending or denting it with human flesh...I think the road travelling at 60 mph may be a little tougher than me.......may be

 

Possibly, but it would need to be formed, making it stronger purely by geometry.

 

I'm not advocting the use as aluminium as the only route, but considering the benefits of it in this application and the potential failure mechanisms of other materials (devils advocate if you like). You may be right though, steel/titanium could be a better option.

 

Andy

[oldbutnotslow]

I’ve read the latest posts with interest.

I understand the issue about the softness of aluminium and also agree with the principle of it acting as a skid. Incidentally it would have to me made from rolled sheet. If strength is an issue perhaps "dural" - said to be the same weight but stronger therefore perhaps a thinner lighter weight version may be the answer.

I "feel" a gap of 1 cm between the sump and guard would be about right. This together with a 4 mm thickness would reduce ground clearance but again being totally selfish I am really only interested in protecting the engine from impact on the track as I very rarely drive my car on the road.

Other contributors mirror my view. I’m not just protecting the actual sump pan but trying to eliminate the catastrophic effect on the engine caused by the sudden loss of oil.

Pierre Gillet a 7 owner in France made a post previously on this subject which may be of interest

I have one made of GRP. It is sold by SV Automobiles, located between Paris and Le Mans in Brou , Fax 33 2 37 47 85 45, tel 33 2 37 47 83 33 ,the garage that builds the Sevens in France. It weighs 2,450 kg (I made the holes myself in an attempt to make it lighter!) It is robust (surface is a bit rough where there is less gel coat), takes 1 cm out of ground clearance, and is easy to install on the engine support bolts (might be necessary to use longer ones)

Pierre

---

.

 

NOT SURE ABOUT THE WEIGHT AT 2,450KG THOUGH !!!!!!!!

 

The so called 'luge en kevlar' looks to me to be the sump guard sold by SV. I painted mine in black, and drilled holes for better cooling and weight reduction.

I don't think it is made of kevlar, but rather simple polyester.

It is pretty cheap too: I paid about 100 € last year when I picked it up at SV. Pierre

---

.

see

http://photos.heremy.com/Petrus7/1715063475.jpg

http://photos.heremy.com/Petrus7/1715073475.jpg

http://photos.heremy.com/Petrus7/1715083475.jpg

 

I’ve tracked down the owner of the car on A & T site it belongs to jf_renard who also lives in France.

The sump guard on Angus site is mine.

I had it made from 5mm thick ali. Quite heavy (didn't measure) but very efficient.

I did it after 3 "3 litres of Mobil1 and a competition gasket set from Burton including P&P to France" operations in 2 years. And as my engine is a BDR, I prefer not to run it out of oil....

You can see several designs on the best French website about 7s , including my design and a hand sketch of it under "La luge en alu différente"

If you can read it, cotations are in centimetres.

The most difficult is to fold it at the right angles. I had it folded approximately by the craftsman who made it, then preceded by "test and fit" method with a big hammer and my 97kg own weight.

The Webmaster did the same and it worked as well, so if it worked twice it should work for anybody.

The skid-shape rear part is very important if you go backwards in the grass at a track day ....

Hope that helps. Jeff

---

.

If I have any chance of doining a deal with the engineering company we need to decide just what we want.

I've sent pictures of the jf_renard sump guard to them but as yet I have not had any further contact.

What ever happens I will have one made up for my car!

 

 

Grant

[mahatma]

Grant,

 

On the continent, a "," replaces a "."

 

The weight of the guard you posted details about is 2.45kg

 

Andy

[oldbutnotslow]

I guessed that this would be the case!!

 

Grant

[Tony C]

I attempted to measure my SV engine mount bolts relationship, for comparison purposes. Unfortunately the bottom of the engine prevents a straight tape - I'll have to use a length of wood with a couple of nails through it. I'm fairly certain it'll be different to the narrow version though 😬

 

Laying on my crawler and giving the lay-out a good eyeballing makes me think the skid plate doesn't need to be very long - probably just enough to make a "ramp" between the chassis cruciform and just aft of the sump leading edge.

 

I think stainless steel will be a good material - it can be thinner than aluminium/dural for the same properties and it will probably only be subjected to a glancing blow - hopefully 😬

 

Just some thoughts.

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[Nifty]

I'm with you Tony *thumbup*

 

Don't be too hasty with the aluminium Grant.

 

Ernie will be back from his hols on Monday and may give us a better insight to the material properties.

 

 

Andy,

Will this not transmit almost all of the energy to the mounts ? Or if the steel/titanium bends, just load up the sump locally ... resulting in a similar scenario to if it weren't there?

If the plate is secured underneath the chassis rail and by matter of fact includes a bend in the plate then any significant impact will cause the plate to bend within itself and not affect the chassis alignment at all. If your scenario would happen then my chassis would be bent like s**t from the impact the sump received a couple of weeks ago.

 

I'm not happy with aluminium so count me out if you go down that route.

 

Keep off the straight and narrow 😬

 

 

 

 

 

Edited by - Nifty on 20 Aug 2004 23:05:42

[Grim Reaper]

I find that most sump/ground interface events are with 'speed humps' that are too short for their height.

The front wheels get over the hump but drop the sump onto it straight afterwards, this then leaves the sump in contact with the hump and it scrapes along until the angle of the engine allows it to part company.

I think that a nylon plate (similar to an IKEA chopping board) would give the necessary protection to the sump but not give much drag to allow it to 'slide' over the ground more easily.

A bend at the front would help in cases where the obstacle appears between the wheels and the sump is the lowest thing it can hit, usually front edge on giving a severe braking effect, a ramped angle towards the front would/might assist in easing the deceleration and lifting the sump over the obstacle rather than it hitting in one sharp blow.

Nylon should be formable with heat to allow shaping and around 6mm thick should be enough to give some impact strength.

All we need now is a supply of very large chopping boards to try it out. 😬

[oldbutnotslow]

Hi Nifty,

Sorry if I mislead with the last post. What I mean is I will have a sump guard made - not yet decided upon the material!

I’ve not met Ernie (yeh I know it my fault for not coming to a meeting!!) but I am very happy to take advice on the most appropriate material.

I wait further comments with interest.

By the way GR I like the Blue Sky thinking - Nylon chopping board = neat idea!!!!!!

 

 

Grant

[Bob Simon]

Grim Reaper has the right idea!

 

99% of my groundings are speed bumps or fast rises out of intersection drain pans.

 

Two bars of UHMW polyethylene (cutting board material) on some kind of structure either side of the sump might be all that's needed. This would leave the sump accessable.

 

...two bars of magnesium and you cruise East Los Angeles with the homies. 😬

 

 

 

 

-Bob

95 HPC VX

 

[Tim Robinson]

I had a steel one on a mini that transfered the damage to the mounts. I would be thinking GRP or carbon or nylon. You want to reduce the damage from bumps and scrapes. The big bangs are always going to damage something like the mounting points. Grp will bounce back into shape and is easy to repair. Kevlar is not as strong but won't tear and ist harder to repair and carbon you would throw out. GRP with a thin replacable stainless skin rivited to it would be quite good.TIM

[SLR No.77]

Bob, don't give Grim "all" the credit - it's more or less what I was suggesting! I like the idea of the Ikea chopping board type material - the protection needed is against a glansing blow (such as on the track) - anything more and something's going to give anyway. It might even be worth cutting some strips of a chopping board and bonding them in between the fins - this should give ample protection in speed bump & sleeping-policemen situations.

 

If you're repeatedly hitting big items that'll cause major damage then either increase the ride height or look where you're going

 

Stu.

 

[henk]

why not look into the possibilities of making the sump guard, in a hybrid carbon/kevlar material,toolings not a problem, layup is simple. More in keeping with a caterham,regards

[Frying Pan]

Hmmm...

 

I'm being dragged to IKEA on Monday by SWMBO - might get a new chopping board or two 😳

 

So how do I bond it on?

 

Guy

[oldbutnotslow]

Mmm,

So what we need is a

Carbon Kevlar aluminium dural grp nylon titanium steel composite ❗

All starting to look like a committee designed horse - but great fun though ❗ 😬 😬 😬

 

 

Grant

[SLR No.77]

... and that's just to make a breadboard

[Slomove]

Interesting discussion....

I don't want to claim that the sump guard I have on my car fits all mentioned requirements but I am satisfied

 

When I got my car it had a simple steel sheet guard (maybe 1.5 mm) installed, with a ramp in front of the sump, a plate below (with some holes to make lighter and 1/2" clearance to the sump) and slanted "ears" to attach to the chassis. That worked well for the occasional speed bump or grounding by compressing the front suspension in a dip. The sump guard just makes a nasty crunching noise and slides over the obstacle. Of course it happens more often than without guard but no consequences. The guard may wear through sometimes but can even be patch-welded easily. I don't really see a point using stainless. As a disposable piece mild or alloy steel with primer is just fine.

 

I almost killed my sump anyway by running over a grapefruit-size solid rock (here). That made a fat dent into the steel sheet (here) and knackered a sump fin. Such rocks are everywhere in the area and therefore I reinforced the guard (here).

 

Very safe, but quite heavy. But it is easy to take off for track use. There ain't no speed bumps on the race track (I hope).

 

Gert

 

Edited by - Slomove on 22 Aug 2004 00:43:55

 

Edited by - Slomove on 22 Aug 2004 00:45:20

[grumpy the 7th]

Anybody though of fabricating a STEEL sump 🤔 🤔 🤔 🤔 same profile as the ali one with longitudinal ridges for scraping over speed humps. This would keep the ground clearance the same and if we're looking at adding extra weight for a guard why not add it to the sump 🤔 🤔 🤔

 

rog

C7 TNT (Honda Irish Green and Peugeot Graphite grey - it's dynamite)

http://www.seven-ecstasy.co.uk/html/stoneleigh04_64.html

 

[Nifty]

What's the danger of the impact then causing the ali crank housing from becoming damaged 🤔

 

Keep off the straight and narrow 😬