S4s rolling restoration project

[tomcattom]

Made some good progress on the car today.

I've replaced the three rivnuts that secure the bottom edge of the left hand side engine bay panel because a previous owner/mechanic had resorted to cutting the bolt heads off because they were spinning in the body.

 

I then set about trying to get the drivers side oil cooler properly plumbed in once and for all. I sought some chemistry advice from a friend and ended up using a solution of Sodium Hydroxide to disolve the remains of the alloy threads left by the scrap oil cooler from the steel oil hose fitting.

I used about 150ml of warm tap water mixed with 50ml of Sodium Hydroxide in a plastic paint mixing cup. This was then sat in an ice cream tub that was about 1/3 full of boiling water because heat improves the reaction and then the hose end lowered in.

The mix immediately start reacting as the Sodium Hydroxide turns the aluminium in the steel fitting to Hydrogen. It took about an hour before it stopped bubbling and the Aluminium has been disolved.

Chemistry in action

If you're planning to do this yourself, please please please be careful. Sodium Hydroxide is nasty stuff, so make sure you wear appropriate face and hand/arm protection and make sure you mix the Sodium Hydroxide into the water, not the other way around and do it in a well ventilated space.

I rinsed the hose fitting off and then smeared a liberal coating of Duralac to the oil cooler fitting and everything buttoned up perfectly at last 😌

 

I then completed the rebuild of the cam housings. Here is everying stripped down ready for cleaning.

I used a scraper to clean the worst of the old Permabond off the head mating face and then lightly went over it with some damp 1500 grit went and dry paper to throughly clean the surface.

Before:

After:

Everything cleaned up and ready to reassemble. The old cam seals left quite a nasty rubbery residue baked onto the cam housing surface which took quite a bit of time to clean up.

I used a smear of Graphogen on each camshaft bearing surface in the cam housing as per the manual

The camshaft was then carefully inserted and then I installed the front cam shaft seal. I find a rolled up bit of plastic sheet really useful for making sure the inner sealing surface of the seal goes over the shaft without distorting; it can be simply pulled out once the cam seal has been seated flush with the housing face.

Finally the cam pulleys were installed and bolts torqued down with Permabond A131 on the theads and a new O-ring seal installed in the cap on the back end of the shaft.

All ready to go back on the car when the remaining seals for the head turn up.

[Jacques]

Yes, that chemistry is a really dangerous very strong alkali. Just a few seconds of inhalation of the gasses it develops, and you're done: permanent lung damage. I know, because I have been exposed jsut a little bit very shortly despite protection, and I arrived in intensive emergency with strong chest pain, a very strong strange taste in the throat and lots of blood pouring out of my nose, and after some hours of blood analysis, blood cleaning and lung examination etc, I was told by the doctor, that I had no damages at all, being the only case he'd ever seen or heard of.

so, I will repeat it: BE VERY CAREFULL!  AND USE A FULL FACEMASK  AND FULL BODYPROTECTION, WITH THE CORRECT FILTERS PLUS VERY VERY GOOD VENTILATION, AND WARN ANYONE ELSE AROUND TO KEEP CLEAR FOR A PROLONGED AMOUNT OF TIME!!!

If exposed, it can eat through skin, bones, flesh, the lot. So better do it propperly or not at all.

Other than that, nice work!

Kind regards,

Jacques

[tomcattom]

That sounds like a rather unpleasant experience @Jacques, glad to hear you survived with no ill effects!

The origami heat shields arrived in the post earlier in the week and when I went to fit them I noticed the passenger side engine mounting bush was sort of slipping out of the bottom of its metal cup so I decided I would just replace the engine mounts while I had reasonable access. The drivers side mount bolt came out without any problems, the passenger one I wasn't so lucky with. The bolt was welded into the bush so I ended up having to cut the top off the bolt and lift the engine up off the mount.

Here is the remains of the passenger side mount, as you can see the rubber has completely parted company with its metal cup/surround

New pair of mounts, buffer washers and all new hardware ready to go on

Mount all fitted to the chassis and torqued up.

 

The engine was lowered down and the new bolts fitted with a liberal coating of copper grease, followed by the engine mount heat shields. Fitting them wasn't as complicated as I was expecting it to be, it was just a bit of a fiddly job assembling everything in the correct order. The engine is now sitting noticeably higher in the chassis with the new mounts.

 

Finally I fitted the Alunux manifold. I couldn't manage to fit it in situ with it fully assembled so I ended up splitting it down into its component parts and assembling each pipe onto its respective port loosly so I could manipulate the pipes a little and then fitted the collector - that was a tough old job getting that back on. Once its was all assembled again I could torque the manifold down onto the head studs.

Hoping to get the cam housings back on the car tomorrow.

[Jacques]

Thanks. Fortunately and thanks to my very active guardian Angel, I am

Looking very good. But seriously, you can spare the engine mounts, no need to renew those, they look really fresh.

How about the gearbox mounts?

I would install a piece of heat insulation on to the frame tube closest. I did that on mine, to protect the galvanising.

Kind regards,

jacques

[tomcattom]

The gearbox mounts look to be in far better condition than the engine mounts by a long way but I did buy a set of poly gearbox mounts from PNM at the same time. I'll probably wait to fit them when I tackle the various gearbox tasks on another occasion.

What did you use to insulate the chassis by the the manifold @Jacques?

[Jacques]

I used a piece of soft heat insulation like on the picture, which contaníns some layers of aramid and a silver foil layer, and fastened it with some metal ties. Works well and is still intact after a few years. The ties are those that is often used to hold drive axle rubber boots in place.

I got the same poly gearbox mounts as you. To be installed once I have new bolts etc. but everything is closed over here.

Kind regards,

Jacques

 

[tomcattom]

Cam carriers were on the menu today. I started off dry assmbling each cam housing without the tappets to check that the threads in the head were okay; I was especially worried about the threads in the exhaust cam housing where the bolt was completely missing. Thankfully they all torqued up fine so I turned the crank back 90 degrees to get all the pistons at mid stroke ready to fit the cam housings.

I coated the tappets in Graphogen and inserted them into the head and then ran a bead of Permabond A136 around the perimeter of the cam housing going around the outside of the bolt holes as instructed in the workshop manual.

The head surface had already been cleaned, the oil O-ring installed and the shims placed on their correct valves. Then it was on with the head and I carefully tightened the housings down to the specified torque in the specified sequence.

First carrier in place successfully.

 

Once both were fitted I then cleaned up the Permabond residue that had squeezed out as best I could and then set about checking the valve clearances again, hoping all would be as I planned 🤞

The inlet clearances measured right in the middle of the specified range, the exhaust clearances all came down a fair bit despite me only adjusting two shims; I guess the lack of the bolt and a thickish layer of permabond on that housing gave artificially high readings. Luckily they are all consistent and within range albeit on the lower end of the specified range.

	Exhaust	Exhaust	Inlet	Inlet
Valve	Before	After	Before	After
1	0.27	0.26	0.10	0.15
2	0.30	0.26	0.14	0.14
3	0.29	0.26	0.11	0.15
4	0.29	0.26	0.15	0.15
5	0.26	0.26	0.14	0.14
6	0.29	0.26	0.13	0.15
7	0.27	0.26	0.14	0.14
8	0.28	0.26	0.08	0.15

 

Satisfied that the cam housings were all sound I cleaned up the cam housing plugs and fitted them with fresh rubber O-rings. The cam covers are just lightly screwed down for now to prevent dirt getting in until I'm ready to start up at which point I'll oil the cam lobes again and fit the gaskets properly.

Pretty productive weekend on the whole

[Barrykearley]

Don’t forget the cam belt 😎

[tomcattom]

New Magnecor KV85 plug leads have been installed along with the freshly painted chargecooler mounting bracket and polished heatshield.

 

I then attempted to test fit the turbo onto the manifold and ran into a fitment problem. The turbo won't drop down fully onto the exhaust manifold flange because the coolant feed pipe on the back fouls on the heatshield 😕

 

With things as they are there is still a good 10mm gap between the turbo and Alunox flanges.

 

Anyone else had this problem fitting the turbo to the Alunox? I could remove some of the spacers/washers in the heatshield arrangement on the back of the cylinder head, but I'm not sure if that will give me enough room to fully seat the turbo...

[snowrx]

Is there enough slack in the oil drain to re-clock the turbo center section a bit?

[tomcattom]

I'd have to check the drain pipe to see if there is scope to clock the turbo. However I think the bigger problem will be that Garrett say the oil feel should be no more than 15° off vertical and the core is already clocked a fair way forwards as it is. I'll measure it later and see where it currently is.

[Barrykearley]

Time to take an angle grinder with a nice thin cutting disc to the plate and relieve it 😂

[Chillidoggy]

Yes, I had precisely the same problem. I think the Alunox manifold needs re-jigging, the turbo sits too far forward on the flange.

[tomcattom]

What do you mean by rejigging @Chillidoggy? Are you implying there is a manufactuing fault with mine and I should send it back to Alunox?

There isn't any adjustability in the manifold that I'm aware of. I can't slide the flange rewards away from the four individual pipes because the metal straps on it won't line up then.

The only other option I can think of is to remove some of the penny washers from the heat shields and possibly get some different fittings for the turbo coolant feed.

[Chillidoggy]

One S4s being like that could be an oddity. But two the same, and something’s not right. I complained to Alunox at the time, and was told it must be my car at fault, the manifold fitted their jig perfectly.

 

 

[Chillidoggy]

I’m fairly sure there’s something about it early on in my refurb thread. I seem to recall I had to find a different brass elbow fitting. I think they have an odd thread, though. I might have a spare but would need to check first.

[tomcattom]

Clocking the turbo is out of the question then. That's clocked more than what is advised on Garrett's website 😟

[Chillidoggy]

Just had a butchers in the garage, no spares that I can see.

But from my maintenance records, it seems I bought a pair of 3/8" x 3/8" NPT elbows and noted them as being for 'brass elbow for turbo coolant'. This does not categorically mean they're correct, but it's possible.

[Chillidoggy]

7 minutes ago, Chillidoggy said:

Just had a butchers in the garage, no spares that I can see.

But from my maintenance records, it seems I bought a pair of 3/8" x 3/8" NPT elbows and noted them as being for 'brass elbow for turbo coolant'. This does not categorically mean they're correct, but it's possible.

Found it!

[tomcattom]

Thanks Ian. While you were posting that I think I've found your original topic on the matter.

 

[Chillidoggy]

Hopefully that should be what you need.

Can you see why I said the manifold was the issue? To me, the turbo flange is about 10mm too far forward.

[tomcattom]

Certainly seems that way to me too Ian. In fact the cat/downpipe isn't lining up by about 10mm properly either, adding further evidence there is some subtle difference on the S4s. The downpipe can be adjusted easily enough though.

[Sparky]

My GT3 was pretty much the same.  For info I've run it without the support strut for years, and it hasn't flexed down at all.  Changed the union and shoed it in.  I'll have to check to see if it's still in contact.

[tomcattom]

What a frustrating day today has been. While I was out trying to work out how to sort the turbo fitment, to my dismay I discovered that the exhaust manifold gasket on number 1 had slipped off the studs during the the install last weekend and I hadn't spotted it 😠 😢 so I spent a large chunk of this afternoon correcting that cock up. The only silver lining is I spotted it now and not when everything else has been put back in place.

 

1 hour ago, Sparky said:

My GT3 was pretty much the same.  For info I've run it without the support strut for years, and it hasn't flexed down at all.  Changed the union and shoed it in.  I'll have to check to see if it's still in contact.

Funny you should mention that @Sparky I was going to ask if others were running without that brace thing after the various configurations I tried this afternoon.

Once the manifold was back in again I refitted the heatshield with one less washer in the setup and the coolant union removed and added the Alunox mounting plate thing. Unfortunatlely the turbine housing outlet flange seems to foul on that support brace preventing one corner of the flange closing up properly.

 

I tried swapping out the ~6mm spacers against the cam housings for some DIN 7349 heavy washers I had that are about half the thickness to see if that made any difference.

Support brace still fouls just in a different place

 

I removed the Alunox plate from the equation entirely and the turbo finally dropped into place

 

There also appeared to be a bit more clearance for the original coolant pipe adapter, so I tried refitting it to see if it works. It does fit but the adapter is hard up against the heat shield so I'm going to try the alternative fitting because I'm not overly happy with it being like that.

[910Esprit]

What about extending the straps that hold the collector to the manifold pipes by maybe 8mm?   After all there is probably at least +30mm of overlap here.  That may fix all your issues?

Edited February 7, 2021 by 910Esprit