Ian's S4s refurb

[Chillidoggy]

I've only used a TIG  welder once. It was on a 12mm wall thickness, high-pressure steam pipe in Tilbury power station when the welder stupidly let me have a go at it. The result was potentially catastrophic, and the pipe had to be cut out.

MIG is easier to use.

[fjmuurling]

For me it is the other way around, tried MIG once (a long time ago) and never got the hang of it.

Bought a JASIC tig welder AC/DC 2 years ago. It is a good welder (me not, need more practice), the only thing which was not to my liking was the supplied torch, replaced it by a CK which is way better.

 

[Chillidoggy]

This is the bobbin which Lotus glass-in to the body which sits atop of the round bar welded to the chassis. It's a necked oval, possibly made from zinc alloy or something like that, but definitely not steel. I'm now debating whether to reuse it, or machine up another steel boss that I can glass-in. As can be seen in the earlier photo, the finished job is round, the same diameter of the steel chassis boss.

[drdoom]

Non-ferrous would perhaps be chosen for both ease of production and avoidance of corrosion. These bobbins are still available through the usual sources I believe.

[Chillidoggy]

Yup, cast zinc alloy. I can see why they’re necked-in, but I’m unsure as to why they’re oval. They look like something off my mum’s washing line pulley.  In any case, I decided to machine a circular steel bobbin earlier, as it has more contact area. With luck I might finish the job tomorrow, then I can get on with the remainder of the list, which, as per usual, has grown somewhat. The planned engine removal and rebuild has been postponed until this winter, as I can’t find any good reason to do it, other than the fact it’s covered a few miles now.

[sailorbob]

Some of the bobbins are threaded and the oval shape is to stop them turning.

[Chillidoggy]

My original one had no thread (unless of course it had been worn away) over the years. The new steel bobbin is necked in the same, with a deliberately rough finish, and mirrors the whole area of the chassis bobbin below. I’m thinking that will do the job, but I won’t know until I use the car. I should finish it today.

[drdoom]

11 hours ago, Chillidoggy said:

My original one had no thread (unless of course it had been worn away) over the years. The new steel bobbin is necked in the same, with a deliberately rough finish, and mirrors the whole area of the chassis bobbin below. I’m thinking that will do the job, but I won’t know until I use the car. I should finish it today.

Threaded bobbins are readily ID'd by examination of the Parts Manual, as there will be no nut spec'd for fastener retention. Most are for use with through bolts.

Cheers

[Chillidoggy]

A bit of progress.

The new wheel bolts, nuts and valves arrived today, along with an email to say the Radinox rims have been dispatched from Germany.. I went to see the inners and centres earlier, they’re ready to be powder-coated, and I should pick them up on Saturday. 

[Chillidoggy]

12 hours ago, drdoom said:

Threaded bobbins are readily ID'd by examination of the Parts Manual, as there will be no nut spec'd for fastener retention. Most are for use with through bolts.

Cheers

I couldn’t find the bobbins listed in the S4s parts manual. Maybe they’re listed for earlier cars?

[Sparky]

In the '88-'92 parts manual they're listed under 10.04A,  #C075B2165Z.

[Chillidoggy]

That’ll be why I couldn’t find them. In any case it matters not, as I have the Margate Exotic’s improved version ready to be glassed in.

[Sparky]

[silverfrost]

Sparky has the right idea,  screw that down to the body,  tie rope around the chassis to that and mak sure you do a good knot 

[Chillidoggy]

Just picked up the freshly-done wheel inners and centres. Looks like a nice job, but I'm not sure whether I will have to remove the new powder-coating on the bolt flanges.

I also need to find a suitable sealant, which is proving more difficult than I thought as there's such a huge range on the market, none of which appear to state whether they're suitable for sealing split rim wheels. Who'd a thought, eh? Maybe RTV will do the job.

[Giniw]

@Jacques made it recently so I am sure he will have a few hints

As far as I know (that is what I have read), you have to screw the rims dry, and then put the sealant — no sealant on the matting surfaces.
But I suspect you already noticed that when you split the rims.

[Jacques]

I did not apply sealant between inner mating surfaces, as they can sometimes make things go wrong and not sit straight. This would make a wheel dangerous and wobble.

And I applied the Pactan 7043 in two rounds with two beads laid down each time, then smoothed out with a wet finger or a tool. I made sure there wouldn't be any edge that a tyre being fitted can get caught on, thereby risking the quality and integrity of the sealant. With a few days in between each of the two layers, to give it time to cure.

I would personally remove any lacquer or powder coating or similar from the mating surfaes, before bolting them together - for the same reasons.

From factory, there's no sealant and no paint or lacquer on those mating surfaces. And it's not because it's just sprayed all in one go. Each part is done individually and in different materials. So for safety reasons and sealing well, no stuff in between. That's how mine were from factory.

I also specifically bolted the parts marked 1-1-1, 2-2-2, 3-3-3 and 4-4-4 together with just a few bolts and then went to a tyre fitter and had them spin it up on their computer controlled measurement machine, which measures balance AND road pressure, to see if it was mated together correctly, or you will seal it all for nothing and will have to remove it all again and undo it all again and rebolt it again etc. After this check, bolt it all up to spec and check again by measuring if it jumps or in any other way is not centered. Then seal it up twice as described and then fit tires and redo balance again, this time with only a few grams of weight

Make sure you tight them correctly and not to much or too Little. I've seen people mantioning lesser torque on old used bolts and that is maybe something others can comment on. I used factory spec and bolts are 10.4 grade steel then hard cromed. Nuts are more mundane. Each bolt is clearly marked O.Z

Other bolts can be bought (not originals) and should be 10.4 is used. I did not trust those and used the OZ bolts again after having cleaned them completely, so no old stuff on the threads. I spoke to a Wheel cpecialist about this and he said they are safe to use. Others may think differently. I just think all this is worth mentioning.

Those numbers mentioned are suposed to sit aligned to each other and balance the Wheel. Those numbers also sit exactly in front of where the valve stem hole is positioned in the outer lips. So all should be aligned: inner star, inner drum, outer lip.

The road pressure can counterbalance for any grams of weight, saving you problems, and lowering road tear as much as 5000-8000 kms extra on a set of tires. Worth doing.

 I also only used strong metal valves, no rubber stuff here.

After this, my wheels are perfectly running smooth, straight and cemtralised and is completely air tight.

Kind regards,

Jacques

 

 

[Giniw]

1 hour ago, Jacques said:

I used factory spec and bolts are 10.4 grade steel

Are you sure they are not 12.9? Maybe I am wrong but this is what I remember, though?!

[Chillidoggy]

I bought new bolts and nuts, the ones that were fitted weren’t the original OZ, the chrome had started to come off some of them, and given I’m spending a cart load of cash, I figured what the hell, a bit more won’t hurt. Right?

Of course when the new Radinox rims arrive (they’re on they’re way from Hamburg right now), they won’t have any number stamped on them, so it’ll be ‘suck it and see’ when it comes to balance, although they cannot possibly be as bad as they were before they were straightened.

I’m up against it time-wise now. The chassis mount repair is nearly finished, and then I’ll have a look to make sure the other side isn’t damaged. At the same time I’m also developing the Delco brake kit further, and have a long job list which I’d like to finish before I put the car back on the road. I need to retire, or at least give up the day job!

 

[Jacques]

Sorry, they are 12,9 steel.  I looked it up and it says  12,9 grade. My bad.

Cannot buy some like that that I know of. Only 10,9 steel, stainless forged to 8,8 or Ti6Al4V titanium bolts.

Ian, you should like those numbers on the inner star and the inner barrel up, and then place the new Radinox outer lip on top, so that the valve hole is aligned together with the stamped numbers on the inner barrel and the inner star. See attatched Picture in the above.

Kind regards,

Jacques

 

[Chillidoggy]

Jacques, I'll have another look to see if there are any numbers stamped on the inner rims.

Felgenfuchs supply bolts for the OZ wheels which are 10.9 grade, that's what I have here. I got mine from SRR wheels here, they were quite a bit cheaper.

 From what I can see so far, Pactan is only available from Germany, and it's way too expensive to get it here. Given what I took off the old rims, I'm pretty sure RTV was what was used before, and it's much less expensive.

[Chillidoggy]

Trial fit, and I reckon that GRP is about as thick as Thanet bird, so I can start putting it all back together.

The bad news is I noticed a leaking damper while I was underneath the car. Bugger!

[sailorbob]

Wheel Power Devon in Torquay might have Pactan 7043 available.

[Chillidoggy]

Thanks Derek. I e-mailed the UK agent yesterday to see it there are any local dealers, should get a response tomorrow. Depending on the outcome, I'm now thinking Sikaflex 291 as the alternative.

[fjmuurling]

Sikaflex 291i is good stuff. (polyurethane based).

As a side note I would be carefull with using silicone as they can contain acetic acid (not all of them).