weld your own gated sump action

So, I’m a good way through the sump build and I thought I’d share a few thoughts on the way.

Having a heavy bolt-to jig helps. Mine’s made of 10mm thick mild steel. The sump is bolted to it at every bolt point to prevent warping and to act as a reasonable heat-sink.I’ve also repeatedly offered it to the block, front cover and ally bellhousing to ensure accurate fits.

 

For some important steps, I used the engine in situ as a jig and actually tacked in place on the block. I’ve been pleasantly surprised at just how well everything mates up.

 

 

The steel around the bottom of the flap-gates is very thin and prone to warping. This can be helped with a flat-bill welding clamp before you start. It’s a good tool for the job but means positioning all the parts and the job at the same time can be tricky.

 

Part of the quality of this sump is that it mounts to the front plate as well as the base of the block. However, this means (in my case) that I need to tap stainless steel. Normal taps don’t cut it, so buying a specific, decent stainless tap has helped, as well as good cutting-oil. I don’t need shed-loads of this, so I’ve bought it in spray form rather than liquid. You need cutting oil rather than (say) WD40 because the cutting oil can still lubricate the tool even at the extremes of pressure when cutting stainless, whereas a normal oil blend would break down. It’s funny stuff – like a very light oil but it seems to hang around the job when normal oils would have wiped clean or evaporated. I use acetone to clear it all away before welding. It acts as a solvent as well as evaporating away nice and quickly. It helps to buy it in industrial quantities rather than at the chemists. Also, I like the smell. Oy Vey – always with the complex hydrocarbons.

Here it is, with the gates hanging down and bent into place. I’ve bent this one with a set of clamps and some pressure, but it wasn’t as accurate as I would have wanted. I’ve moved on and now am using a proper parts former. It requires some lining up by eye, but the result is pin sharp and accurate.

dry build of the engine

So, the build is progressing nicely – I’ve got the sump most of the way there, and learned a reasonable amount of stuff as I go. I’m now at the point where serious chassis surgery is on the cards to get the engine mounted further back and at the right ride height. I can’t do any of these things until I have a dry-build of the engine.

By dry-build, I mean assembling it without gaskets, fluids, or inconvenient cranks.

I originally started with this mucky oily disgusting mess as I stripped the block down. The more astute among you will notice the cat-litter on the floor soaking up the oil dripping out of the engine.

 

 

Now I’m at this stage, with the polished rocker and front cover in place, as well as my totally orgasmic Jenvey throttle bodies. They’re DCOE format (original Webber layout I think) and on an SBDev manifold. Go on, click the link to see them in their full glory. You know you want to.

 

 

 

 

What? You didn’t click? All that red tubular delight and you didn’t click? Alright – here’s another view side on, showing the lovely and compact bellhousing which will hold the new hydraulic clutch.

Again, you can see the side of the block somewhat lets down the finish I have on other parts, so that’ll need scrubbing back and sealing at some point.

sump kit ordered

So, I’ve ordered the plans for flakmonkey’s duratec sump. I’ve ordered the parts to be cut in stainless from Yorkshire Profiles. I didn’t ask if they were laser or water cutting it (ideally water – no need to heat the stainless up) and the thickest part is the flange to engine at 5mm.

Interestingly, the economics of getting parts cut mean that the unit cost drops rapidly once the job has been set up.

The costs break down as follows:

Quantity Overall Price Unit Price inc vat % reduction
1 £106.99 £106.99 £128.39 0%
2 £136.58 68.29 £81.95 36%
5 £302.20 60.44 £72.53 43.5%

What this doesn’t include is the £10 I spent buying the plans, costs of argon or stainless rods. Nor does it include a license to reproduce from the set of plans I bought. The chap selling them didn’t mention reproduction but if I was to flog a sump, I’d pay him another £10.

So, I’ve ordered two sets of sump parts in 304 stainless. Nice to weld. Nice and clean. Very easy to get a neat tig weld.

If you were to buy a cast sump the costs come in at £350 onwards, and even a welded stainless one (specific for a MK2 escort) comes in at £300+.

Add strength for little weight – seam welding

So, I remember from years ago, a friend of mine told me how he prepares RS2000 shells – after buying a second-hand one in good shape, it would be stripped back to the metal and seam welded rather than spot welded.

Mine isn’t seam welded where some of the strong panels join the spaceframe, but stitch welded (i.e. one cm of mig welding for every 5 or 6 cm of space). It’s quick, stronger than spot welding, but let’s face it – it’s an economy solution.

So, now I want you to queue the Ghostbusters theme in your head and hear me sing “welding makes me feel good”. As a result, I thought I’d quickly try a couple of quick seams in an easy to weld area to see if it’s worth the hassle. Quick answer is yes.

There are a couple of issues with the quick approach I’ve taken to see if it’s sensible.

  1. Firstly, grinding the existing the existing powder-coat back isn’t too tough a job (circular belt on the dremmel) but you need to go back quite a way, which I didn’t. The heat of the weld made the powder-coat peel back. I’m going to get a blow-torch and see if this will get more of the powder-coat off. This leads me to my next point:
  2. The powder-coat gives off fumes when burning away. I’ve had a sniff of this and it’s not pleasant. I will need to do the burning off with the garage door open, ideally with a breeze. Once I’ve burnt off the bits I want off, I’ll then weld it. One big burning. Maybe with a fan.
  3. There is a little inevitable powder-coat down between the gap of the panel and cross-member it’s stitch-welded to. This will cause a little pollution of the weld. I have a really nasty pointy grinding tool for the dremmel which gets most of the powder coat out. It’s evil, and I’d love to turn it on a dentist some time.

So, here’s the welds – they look good and really nicely round the corner off. The holes aren’t blow-throughs but screw-holes from whatever was mounted on there.

And here are some photos:

  

Here you can see the first weld, and the second shows stitch between the seams.