Custom Sump Skid/Kick Plate

[dapinky]

Not wishing to hijack Jamie's project (and I'm not offering to go into production!) - but whilst under the car doing the suspension, and removing the prongeron (remarkably easy to do) i decided to have a look at the posibilities....

....my first thought was that not a lot protrudes below the prongeron - just a bit of the exhaust and the lowest bit of the sump itself - so a design which basically follows the contour of the prongeron would be ideal...

...next, as there isn't a huge amount of ground clearance at the best of times, something which is basically a flat plate with spacers to the main structure would possibly reduce the clearance too much...

...so I needed to 'shape and bend' the material to put bulges in the right place, whilst maintaining the best amount of space to the road as possible...

...starting to get too difficult for an 'engineer' of my capabilities - until I remembered that I own a BIG hammer

As it needed to be bent in lots of different directions, Aluminium is an easier material to work with than steel, so that was my first consideration - but how thick?

I had a sheet of 2mm stuff, but decided that 3mm would be better, but harder to work with - so I made one out of cardboard! (only as a template!!)

3mm is plenty strong enough for this job, and to be honest, 2mm would have done the job, whilst 4mm would be okay for someone who has access to a professional metal-bending press, but not for hand tools.

I only wanted 'soft' aluminium for a variety of reasons:-
It's cheap!
It will deform on any impact, thus reducing any transmission of impact force into the prongeron.
Any such impact force will be absorbed by the material, and it will act as a 'cushion' if it gets hit hard enough to come into contact with the sump/exhaust.
It's easier to cut and work with, at the expense of ultimate strength/scratch resistance.
It is only really intended for 'road' use, where any contact "should" be more of a glancing blow than a direct impact, and it should just guide & assist the car (sump?) to go over small lumps without getting the important bits damaged.

It took a bit of trial and error to get something i was happy with, but it's now job done!

There are things I will need to keep an eye on, mainly temperature increase in the engine bay (maybe it'll need some sort of ventilation system near the exhaust pipe??), possibility of exhaust/sump or anything else hitting the guard under normal driving as the engine tries to rotate on its mountings under accelleration/decelleration (hopefully I've left enough room, but we'll see!) and the guard vibrating loose over time and/or the mounting fixings being erroded with continued abrasion on the tarmac (hopefully not!)...

Here's the pictures which I managed to get as it was getting dark...

(newly painted) prongeron with guard attached

various shots of clearances

front fixing onto the radiator frame

A few things to consider if you try to replicate something like this:-

1) The prongeron is fabricated by spot-welding the 2 halves together along the flange, so any fittings need to avoid these welds
2) It is just held on with 11 self-tapping flange-head screws, but is solid enough (could have used less - was going to use short bolts, but they would need to be 'captive' so would have to be blob welded to the prongeron - maybe if it isn't strong enough, I'll do it - but we'll see))
3) It can be removed easily without disturbing too much else (front fibreglass cover needs to come off from under the radiator - but that's only 4 screws) - may be possible to reach the drain plug anyway, but i doubt it.
4) needs to have a bit cut out at the front so you can get to the small bolts which hold the prongeron to the radiator frame (I cut a bit more out after I had taken the pictures, so final job isn't shown!)
5) access to the engine steady bar / shock absorber is still possible, but not quite so easy.

On a serious note, you don't need a BIG hammer - a small one is much better for forming Aluminium

Oh, and before anyone asks - it's a sheet of 3mm Aluminium, 600mm long, 300mm wide - cheap enough on ebay - and I've got enough left for something else (like to protect the gearbox the other side!)

[Elanlover]

When do you begin production Dave?


Dave's Hand Hammered Sump Plate With Skinned Knuckles (almost free 'cause he's a good guy)

1) Elanlover

[Elanlover]

So, more seriously Dave, how did you form the aluminum? I'm not referring to the hammer I see there but was the prongeron on the car when you did this or off? Just trying to understand how it would be possibly to get it right (with regard to covering the pan and exhaust) with it off the car?

[dapinky]

Blair - it was a bit of trial and error, involving fitting and removing the prongeron a few times (not fully, just a couple of bolts to hold it in place).

I started with the prongeron fitted, just to see how much of the engine/exhaust dropped below the profile (not too much), and just measured the size needed - decided I could get a sheet of alluminium for a good enough price, so ordered it.

Originally, I had thought of mounting it quite rigidly to the prongeron, with bolts and things, then decided that it would possibly send too much shock into the chassis in case of an impact, and it is only really for deflecting the blows that may occur (and the need to remove it for access to bits we need to get at.).

I made a rough cardboard template, basically just between the prongeron (right side) 'leg' and the radiator mounting frame - it was remarkably 'square', but needed a few bits to be cut away later.

I then transferred the rough outline to a sheet of alluminium, and cut it to about 1" oversize all round.

By holding the sheet in place (used a couple of big spring clips [like these] to hold it in place (and a bit of 2" square timber to prop up the inner edge). By looking in from the side (quite easy whilst the suspension is incomplete) i could see where the sump profile needed to be transferred to the skid plate, so just marked it with a pencil - i then measured where the exhaust would be likely to touch it, and marked that as well.

I was intending to try and do the bending with my shop press, but the arms are too close to get the sheet into it properly and exert the pressure in the right place - so went for the medieval approach of a hammer.

I started off with just a couple of biuts of 2" timber either side of the required depression and smacking it with a hammer (i started with a 2lb hammer and used a panel-beating dolly to form the rough curves, but it could easily be done with just a hammer if you have no dolly) - basically hitting the aluminium into the dip between the 2 bits of timber.

Obviously, because of the 3-dimensinal stretching/bending, it is best done slowly, and 2 dozen small blows are better than 6 big ones! - you will still get some overall dimensional shift and 'waving' of the edges (hence cutting it a bit bigger).

The dent for the exhaust was formed in the same way.

It took a few 'trial fittings' (just holding it up to the car) until i was happy that the dents were in the right place, and deep enough. Then i sandwiched the edges between two bits of wood to straighten them up and make the whole edge flat enough to fit.

The leading edge needs to be trimmed down and bent so that it can meet the radiator frame, then the whole thing was trimmed down to size.

I drilled a couple of 4mm holes through the alluminium sheet and the folded (and spot welded) flange on the prongeron and held it on with a couple of self-tapping screws - again checking the clearance between plate and engine.

At that point the prongeron came off again (it was only held in with a couple of bolts anyway as it had been out for a clean/repaint) and then the plate can be fettled to fit the exact profile required (the lateral arms are not totally flat, but slightly 'cranked', and the longitudinal arm is curved slightly).

It only needed a few light blows with a small pannel-beating hammer to mould it to shape, fitting another screw every 6 inches or so as you go round (far easier with the prongeron removed, so you can drill the holes between spot welds.)

Then just pencil-mark the correct outside edge you want (I had about 10mm overlap between the panel and the prongeron), remove it and trim it down to final size.

Finally (but not really necessary unless you are a concourse-entrant or suffer from OCD), i went round all of the dips i had formed with a suitable hammer, with the panel laying on a sandbag (just an old pillowcase with 5kg of building sand thrown in it!), just to tidy up the visible hammer blows and round-off the profiles.

Then re-fit the prongeron properly, and screw the skid plate on (it ended up with 11 self-tapping screws) to check the fit. It was at that point that i realised i needed to cut a small bit out at the front so i could fit the small bolt which attaches the prongeron to the radiator frame, so had to take it off again! - obviously, this would be unnecessary if the frame wasnt already due to come out for painting and/or future access - as the skid plate needs to be off to do any of that anyway, so as long as those 3 bolts are fitted before the plate, never going to be a problem - but for the sake of a 1" square cut-out, it may be useful in the future???

It is strong enough to do the job, and held well enough not to fall off in an impact - at one point i was thinking of joggling the edges so it would fit above the flange on the prongeron, but decided against it for a couple of reasons'

I'm sure it would have looked neater (but it doesn't get seen!), and it would be easier to drill the holes to avoid the spot-welds without removing the prongeron, but the self-tappers would need to have a decent backing to hold them (you know, the little spring-clips that you use), and any impact on the aluminium plate would be against those fittings, and not into the chassis, making it more likely to rip it away and fail to do it's primary job of protecting the sump from being cracked.

[Elanlover]

Just a thought on your concern about heat in the engine bay. While heat is supposed to "rise" there may be some reduced airflow in general in the engine bay. Although, it shouldn't be really restrictive as there's plenty of other open area for air to get sucked up in the engine bay. Still, I thought about using some perforated aluminum or perhaps, in your case with the work already done, drilling a number of holes in it. This would lighten it (probably not a big deal) but also let air flow up and any liquids flow down and out of the engine bay. Might help reduce heat transfer to the plate from the exhaust as well. I was also thinking about using a bunch of well nuts to attach it as the rubber might act as a buffer to reduce vibration transmission to the chassis.

Its a pretty nice idea Dave and I may very well have a go when (if) I decide to yank off the prongeron for the alternator change. Do you recall what size of sheet you started with (so I know what to order)?

[dapinky]

The overall heat isn't likely to be too much of a worry (i think!) - but it will be monitored. Heat transferrence from the exhaust to the plate may make it a bit hot - but airflow should control that. The main issue is the exhaust pipe heat from the front pipe - i may well end up wrapping it in some lagging tape just to try and control the engine bay temperature - can't do any harm, and may even improve overall heat dissipation throughout the exhaust flow. I may also end up drilling some holes with a 1" hole saw just in the exhaust area.

I'm not sure how the whole thing will affect airflow through the radiator and oil cooler, but it's something I'll have to worry about if/when it becomes an issue - this shouldn't really be a problem, and is also part of my reasoning for only having the plate over half of the engine bay 'floor', and not protecting the gearbox side (which never seems to suffer in the same way anyway.

I bought a sheet of Aluminium which was 305 x 1200 [1 foot by 4 foot(ish)] - and used half of it.

You can start with a piece which is 600mm x 300mm quite easily.

These measurements are for a UK car, so I don't know if the Fed cars may need a slightly longer piece to reach the radiator frame due to the difference in the way it mounts at a bit of an angle.

[Elanlover]

Since the car's still up on jack stands (not for much longer I hope) I've been having a good look under the engine bay with the thought of doing what Dave's done. I picked up some perf aluminum sheet and worked on a prototype for the oil sump when I thought struck me. So, I'm going to work on something that covers the entire bottom of the bay protecting the oil pan and gear box - right after I pick up a bigger sheet of aluminum.

Having looked a lot under there I am concerned about heat. UK and Fed cars have the radiator oriented differently with the rad on a Fed car angled back. This means the fans point slightly downwards towards the ground which is better (I think) than the UK setup where they point straight back at the oil pan and gearbox. But, it means that a solid plate is likely going to destroy any advantage this might provide and trap the heat in the engine bay. So, perf aluminum is the way to go (easier to form too). Frankly, given how hot these cars can run I'd be concerned about a plate that fully covers the area underneath the engine bay but that could just be me being overly cautious. Regarding mounting points one thing I have noticed and plan to make use of is the holes drilled into the bottom of the prongeron.

I found that on a Fed car (same for a UK version?) you can slide the plate to the front of the car past the front mounting point of the prongeron and it will sandwich itself between the black plastic lip that screws into the bottom of the bumpers. It'll sit there without the need for screws as long as the rest of the plate is well secured. On the sides at the front it will slide under where the intercooler and oil coolers are (need to cut out some slots to slide past some bolts on either side) but then you can drill a hole in the plastic and create a mounting point on each side. The prongeron already has a number of 3/8 (or equivalent metric size) holes in the body presumably to let water out. I am planning on using those by inserting jacknuts into the holes to create 3 or 4 mounting points on the prongeron body limiting the need to drill any holes in it. I was thinking about rubber wellnuts but the rubber will one day deteriorate and I just feel more comfortable with steel jacknuts.

I'll likely use some 1/8 think (the 1/16 thick sheet I experimented with seems too flimsy) with a staggered perf pattern that's roughly 60% open. There will be some shaping (around the oil pan for example as Dave so expertly did) and numerous cutouts to accommodate bodywork and a large one for the oil drain plug but I'm anticipating this will work out well. still give some ventilation and not require too many holes (if at all) to be drilled into the prongeron. If it works out I'll post it in my exterior projects thread.

[Jeemy]

Sorry. With all the queries as to if this was even a good idea and other work pressures, I kind of forgot about this. I don't really plan to restart it unless the mood takes me as others have more knowledge than me and I have plenty LEC work to be getting on with.

One note, the holes in the prongeron might be, I think, to put rust prevention in, rather than to let water out per se. I think, anyway. So before you do it, maybe scoosh some dinitrol up there - it can't hurt.

[Elanlover]

Well, I thought I'd be able to take some nice pics and post them under my projects thread but when the guard is already installed and you've only got about 24 inches under the car to work with the pics aren't worth much. Suffice it to say that I used 1/8th's inch thick perf aluminum and covered the sump and gearbox running it about 2/3rds of the way across the bottom of the engine bay (all the wat over to cover the oil pan and enough to just cover the vulnerable part of the gearbox). I cut a section out right where the oil plug is to make it easy to change the oil. The perf aluminum is thick enough to resist denting if struck by all but the largest of objects, is ventilated to allow the fans to do their jobs and was malleable enough to bend and form it with a hammer.

The hard part was fastening it which took many tries and some rethinking. At the front of the Fed car (not sure about OK versions) there is a plastic strip secured by captive nuts. Could be for the rubber spoiler which I replaces with an Esprit one a long time ago. I cut notches out of the material, loosened the bolts and slid it into place then tightened them again. Its a perfect way to secure it in the front without having to drill anything. I was then going to drill a few holes in the main body of the prongeron and use jacknuts to secure it. That didn't work so well as the jacknuts didn't grip the metal enough and the bolts just spun them around. I tried rubber well nuts but I wasn't confident in their ability to hold the guard securely and not break out one day. So, I instead took a page from Dave's book and used SS self tapping screws. I used fairly large ones, drilled 3 pilot holes into the centre of the prongeron (and one off to the side) and secured them with a fender and lock washer. They seem pretty secure. I was able to do all of this while the prongeron was on the car.

All in all this was probably a 3 hour job with cutting, bending, shaping, etc. plus all my "experimental" time that subsequent folk can likely avoid. Great idea to begin with Jeemy and thanks to Dave for his work from which many ideas were shamelessly stolen.

[dapinky]

Just a bit of an update on this thread.

Last weekend I took a local drive up to Yorkshire for Sunday lunch.

Motorway driving, with no hold ups on the way up (very unusual for the M6).

'A' road and Motorway on the way back, but with the expected delays on the M6 at Stafford - 20 minutes of stop-start driving to cover 2 miles.

Anyway, the point of this post is to address the effect on the engine cooling - it was a usual Summer's day (you know, rain on the M62, but sunny for most of it), so it was hood down for the whole weekend.

During normal conditions the temperature guage just reaches the 1/4 mark, but doesn't obscure it (previously there was the slimmest bit of black visible, but not anymore). As such, and without having the elanscan plugged in, I would suggest that there is only very slight increase in running temperature, and certainly nothing to worry about.

In stationary traffic it builds up a bit, and the fans cut in at the appropriate time - bringing the temperature down at the same rate as before this modification (to half way on the guage).

As soon as I started moving again, it dropped down to the quarter mark and sat there.

In conclusion, I reckon there is an increase in running temp of an extremely minimal amount, and no negative effect on the fan cooling rate. (460 miles in 2 days).

(hopefully it won't change, but I'll be keeping an eye on it)

[Peter D]

I would be very interested in a skid plate I can just bolt on.
Was there evere any offer from Reflex Auto Design ?

I need a new sump for 2nd time in 2 years...

[Steve A]

I would be very interested in a skid plate I can just bolt on.
Was there evere any offer from Reflex Auto Design ?

I need a new sump for 2nd time in 2 years...

Having driven on Belgium roads I'm not surprised
If I remember correctly there was a few LEC casualties on the Ypres trip.

Couldn't your sump be repaired/modified Peter ?
I used to have a Westfield which was much closer to the ground so I had my sump reinforced as well as shortened and widened to keep capacity.
I would have thought a repair would be straight forward.

Have you still got your old damaged sump?

[Peter D]

Still have the first one, and will keep this one as well.
It's very thin steel material, difficult to weld stuff on, especially if you want to add thicker material.
And I'm not sure if shortening it is an option.
Replacement is scheduled next Thursday, we'll take a good look at our options to avoid future damages...

[Fredjohn]

Peter
If it's any help I cracked my sump at Ypres last year and managed to get it welded up for less than £10. They welded on a thicker plate of steel over the sump and the split. No problems at all since then.

Took me a bit to get at the sump, but at least learned how it all came apart and went together again.

John

[Peter D]

I'll certainly make it a priority now, to find me a welder with good skills, who can repair and reinforce the sump.
If I fail to find one, I'll send it over to you

[norman lovie]

shaping up an under tray as a sump guard - but also aiming to seal up and smooth out the general surface area = could be beneficial with respect to high speed handling

A sump guard that comes with the obligatory performance add on "up to a 15% improvement" sticker =

[XiPHiAS]

Is this project done?

[simonbuk]

Not too sure on the reputation of the guy at the moment !!