Wombat 33 story number 1 - My 16v boxer

[the wombat]

Bought this at the beginning of May. Main reason was that although I have several 33s, they all need a bit of work, and I wanted something nice to drive through the summer that I could fettle and tweak, but not have to do anything major. This one certainly meets that criteria - very very nice car.



Managed to have a good poke around of the car today. One of things where I thought 'I've got 10 minutes to do that' and it turned into a bit longer.

On account of finishing my lesson planning for my last training week, and marking 2 classes worth of assessed practicals, I decided to have some car time before I get going on finishing my last assignment. It's been a long haul!!

Anyway, the 16v job started as dis-assembling the drivers seat as the outside bolster has a tear in it. I have a local company who is happy to match the material and make a new bolster cover for a fair price as long as they get just the bolster. Well, fannied around with that for a while and decided that the alcantara seat base could really do with a new cover as well as its gone all bobbly and has a few tiny holes appearing, so took out the passenger seat, swapped the rails/seat belt anchor with the drivers seat, and now am minus a passenger seat which is in bits and ready to go off next week and get sorted.

The 33 has spacers under the seat rails, and generally they are small at the front and over an inch at the back to make the base level. There are also slide stops at the back which are almost 2 inches long. So, now large spacers at the front, small at the back with some washers to hold the rails off the carpet, and slide stops removed - hey presto a 33 with a driving position made for a 6ft 2 beanpole.

Then, you know those days when you see a job that needs doing, make a start, and then you wish you hadn't!! I noticed some paint bubbling just above the skirt at the bottom of the OS B post. Looks like the skirt has not been held securely by its fixings and has rubbed through the paint. Decided to take the front skirt section off to clean up the rust bubble and get some protection on it.

I am sure you know how the rest of this goes. When you start poking and prodding old Alfas, you tend to find holes. Whilst its not too bad at all, the whole skirt will need taking off, and worst case a new sill stuck on. Best case, some careful patching in 2 places, some rust treatment, and plenty of protection. Its all under the skirt so cosmetically easy.

Naturally, I had a good look around the rest of the underside, and its OK. Not removed the NS skirt yet but no bubbling in the same visible places. Jacking points and suspension mounts good, so hopefully I have seen the worst.

Tidied up the centre console while the seats were out, and swapped the gear shift gaiter for an original and unmolested or broken one I managed to acquire.

Will be driving this next week and got to get that assignment done, then next job is to stop the NS front suspension squeaking (coil is just rubbing the turret), and then I have a few brake mods I want to do - 2000 Vectra front calipers (bolt straight on), 155 V6 284mm front discs, braided hoses, and a 75 V6 master cylinder (3mm bigger internal diameter to move more fluid for the bigger calipers).

More on that soon.

[the wombat]

Did a little more on the 16v today. Having managed to knock out another 1000 words of course assignment and done some research reading for it on 'Pedagogical Content Knowledge', I became a little distressed and needed a mechanical fix

Front suspension has lowered springs, and every time the car goes over a bump, there is a squeaking/rubbing noise from the NS front. Spoke with Alex and he thought that on occasion, some of the lowering kits cause the spring to just rub the turret, so goal was to get the strut off and see what was going on with a view to solving it.

Strut off is very easy - wheel of, pop the track rod end, remove the 4 bolts holding the strut to the bearing carrier, remove the 4 nuts holding the strut on at the turret. 4 nuts - wait, only 3. 16v strut tops were meant to have 4, so looks like the strut tops or the engine has been changed in the past. That would explain the insurance confusion. Chris Knott had the car as a 1.7 i.e. but the common compare websites have it as a 16v - oh well.

Of course, not as straight forward as it should be. Very bottom of the 4 bolts was turning but not coming out. Turns out the thread in the bearing carrier is stripped. A nut has been put on the back to secure it, but the alloy spacer in the strut has broken and the bolt has seized in the alloy (the discovery of anti-seize paste was a wonderful thing for me). Beat this out, and wondered about longer bolts with nuts, or taking the bearing carrier and hub off and replacing with a spare I have.

Anyone, onto the strut, and the rubbing is immediately obvious. When the spring compresses, the first top most free coil is moving upwards and rubbing the edge of the top mount. It has been doing it for a while as the spring is quite marked.

Looking at the logistics of this, the top of the spring sits in a rubber moulding, which sits in the strut top which is shaped so that end of the spring is against a stop (should have photo-ed it I guess). It looks like the spring is not hard enough against the stop because of the rubber, as if the whole spring was turned a further 10 or 15 degrees to be hard up against the stop, the first free coil would miss the edge of the strut top by a good few mm. Not able to do this, the simple solution is a gentle application of the angle grinder to remove the offending strut top edge. That seems to have solved the problem from a bouncing up and down perspective, and the drive to work tomorrow will confirm it has been successful.

On re-assembly, managed to strip the top thread into the bearing carrier. So temporarily have 2 longer bolts (155 bottom wishbone bolts do the job nicely) with nuts to hold the thing tight, but will replace the bearing carrier and pop new front bearings in while I am at it.

Front disc on that side is - now what is that term... cattle trucked. Caliper is fine and pads look like they have overheated. I pulled the caliper off and popped on one of the Vectra front calipers I have. Perfect fit directly over the tiny disc, and the wheel fits nicely over it. Will be ordering a pair of 155 V6 front discs shortly, and as soon as I get the brake hoses made up, will do the big brake conversion.

Whilst this was all in bits, had a chance to inspect the front NS for rust. Jacking point is good, but all the protection is falling off and a bit of surface rust, so plenty of work to do de-rusting and re-protecting towards the end of the summer. All round the engine compartment looks good, so not bad all in all.

Will do some pics next time, as next piece of work likely to be the big brake thing.

managed to find a set of late rear discs/calipers etc, so at some point, the rear drums will come off as well.

[Steve Webb]

Ahh the joys of a used cars previous history. Always a surprise in store when you start working on it.

[the wombat]

Aye. Its not a bad car though. Some bits to keep me busy!!!

Good news, the suspension doesn't squeak now.

[the wombat]

Some breaking news...

Speedflow make up brake hoses, and are making me a set of plastic coated braided hoses to fit the Vectra calipers (banjo fitting) and 33 hardline fitting (screwthread) for 50 quid.

Ordered a set of 155 V6 discs, just standard reasonable brand OE replacement. The wheel fitting centre on the 33 is about 1mm larger than the 155, so worst case I will have the get the disc centres machined, but no issue with that.

So all the front brake bits are on their way.

And...

I also found this, and am in the process of having the bits I need sent to me for the back end



Rear stub axles, caliper mounts, calipers etc from a very late ABS 33, so, discs all round for Mallory

[the wombat]

Front brake braided hoses turned up today. Just need to get my University work done and I can go and get these big brakes sorted!!

Not sure if anyone has experience of them before, but www.speedflow.co.uk are the company who got these made up.

Very impressed with their service. I emailed them to ask if it was possible, they gave me a good set of instructions as to what they needed to quote, I sent them a 33 flexible and a Vectra caliper hose fitting, and 50 quid later I have a set of braided stainless hoses the right length with the right fittings. Took a week from my initial enquiring to having the hoses in my grubby mits.

Very impressed.

[Steve Webb]

Front brake braided hoses turned up today. Just need to get my University work done and I can go and get these big brakes sorted!!

Not sure if anyone has experience of them before, but www.speedflow.co.uk are the company who got these made up.

Very impressed with their service. I emailed them to ask if it was possible, they gave me a good set of instructions as to what they needed to quote, I sent them a 33 flexible and a Vectra caliper hose fitting, and 50 quid later I have a set of braided stainless hoses the right length with the right fittings. Took a week from my initial enquiring to having the hoses in my grubby mits.

Very impressed.

Nice to hear there are still some places out there that provide a good service.

So what are the specs of the Vectra calipers, and what size disks are you gonna be able to run with?

[the wombat]

The Vectra calipers are ATE single piston and slider off any Vectra 'B'.

They are a straight bolt on replacement but are huge in comparison to the tiny 33 originals. I will measure up the piston area and do some hydraulics calculations (I am allowed, I am a Physics Teacher). I can probably get a part number off the Vectra calipers as well.

Although they are not the most sophisticated pistons in the world, the have a much bigger piston than the originals, and much bigger brake pad area. In theory, I can work out roughly what force you apply on a brake pedal, calculate the moment through the leaver, calculate the force on the master cylinder piston, work out the hydraulic pressure created, work out the force at the bigger piston caliper piston, and use that force to work out the pressure applied at the brake pads to give an idea of the difference (or get a clever student to do it for me).

Disc wise, I am using a set of standard new 155 V6 front discs which are 284mm diameter compared to the 239mm 33 discs.

These will not fit under 14 inch wheels, but do fit nicely under 15s (already done a mock assembly).

I might have mentioned I will be using a 75 V6 master cylinder. It is identical externally, but the bore diameter is 22mm instead of 19mm.

Hydraulically, if I were to use the 75 master with the original set-up, I would end up with less pedal travel (good), but would need to apply more brake pedal effort (bad, as it is already pretty high). I need to check the maths, but using the 75 master with the Vectra Calipers is primarily to shift more fluid with the same travel (bigger calipers = more volume of fluid needed to move the pistons, so more pedal travel with original master), but I think this should keep the brake pedal effort about the same as well for much more force available at the caliper.

The interesting thing (for some) is that pressure = force/area, so there is a play off between more force at the piston, but that force is acting on bigger brake pads. Bigger brake pads/discs are better generally (better heat dissipation etc), but not if the pressure you can exert on the disc becomes less than the original pads and discs.

Will be starting this later this week hopefully, so pics to follow and some technical info and calculations.

[wrinx]

The interesting thing (for some) is that pressure = force/area, so there is a play off between more force at the piston, but that force is acting on bigger brake pads. Bigger brake pads/discs are better generally (better heat dissipation etc), but not if the pressure you can exert on the disc becomes less than the original pads and discs.

I was having a similar discussion elsewhere about brake efficiency and area, it concluded that a larger surface area did not improve the braking ability as such, but did so by improving the heat dissipation ability of the set up via larger discs and pads.

I still can't get my head round it (a much smaller pad just wouldn't work, but is it heat or friction by area?), but the others produced tech articles which agreed with their POV so who am I to argue...

wrinx

[Steve Webb]

I am allowed, I am a Physics Teacher

Is it wrong that my mental picture of you just changed.

Anyone remember Denzil Dexter from the Fast Show?

[the wombat]

It is an interesting thing to explore (again, for some ).

I think the pragmatic story goes something like:

Effort on the brake pedal needs to be light and with some feel, so as a hydraulic system can be a force magnifier (with the trade off being pedal travel), a small master piston size is good.

Feel can be built in based on the pedal travel versus how far the pads at the other end have to travel, and how the friction material starts to work (heat comes into this as well)

Just to finish the pedal end of things, it is a little more complicated as we are not just applying a force straight to a piston, there is also a lever system (pivot, force, and distance from pivot that the force acts) which also allows some pedal travel to be fine tuned. And there is a servo!

So at the caliper end of things, the bigger the piston, the more force can be applied. The trade off again is piston travel. For a given amount of piston travel and fluid movement at the master end, the larger the caliper piston area, the less movement.

Ideally, if you have a whacking great piston at the caliper end, and the brake pad is the same size as piston, all is well.

I will do the calculations for the original front brakes/master, and the new ones, but from an initial simple view:

Original master (19mm dia) for a force of 100 Newtons, pressure exerted on the fluid = 35.2 N/cm squared

New master cylinder (23mm dia), pressure = 24N/cm squared

So straight away you can see why you have to push the pedal harder on the larger master, as the increased piston area means less pressure exerted on the fluid. There will be less pedal travel though.

At the caliper end, I don't have the measurements yet, but just as an example, lets say the original pistons are 3cm dia, and the Vectra pistons are 5.5cm dia

Area or originals = 7.1 cm sq.
Area of Vectra = 23.8cm sq.

If the pressure of the original master is 35.2, Force at the caliper = 35.2 x 7.1 = 250N

If the pressure of the new master is 24, Force at the Vectra caliper = 24 x 23.8 = 571N

So we have more than doubled the force at the Vectra caliper for the same effort at the pedal (and hopefully balanced how much fluid to move).

So on to pad size.

No measurements again, but roughly, lets say the originals are 8cm x 3cm, and the Vectras are 10 by 5.5

So, original area is 23cm sq. Vectra is 55cm sq. Double this for 2 pads (both sliding calipers so force is still only coming from 1 piston - now that is why multi-piston calipers are better)

Original pressure = 250 / 46 = 5.4N/cm sq.
Vectra pressure = 571 / 110 = 5.2N/cm sq

So there is your dilemma. Pressure at the larger pad is less than the pressure at the original pad (based on my estimates) even though the force at the caliper is much greater.

Amonton's laws of friction state that it is proportional to force, and independent of contact area, so in the calculations above we have produced a less effective braking system, which is counter-intuitive.

When I get the actual measurements of everything, I bet we will find that actually the larger calipers and changed master cylinder make a slightly more effective braking system, but perhaps only by 10% or so.

It is worth seeing if the original master cylinder is adequate for the new calipers at the expense of more pedal travel to move them, and I might try that as it will move things more in the right direction.

So, interesting right (don't you just love Physics!!!)?

There are many more factors or course, and the larger disc and pad to spread the resulting heat and dissipate it is an important factor in brake performance when time applied is taken into account, and the impact heat has on the material in contact, the brake fluid etc.

More on this when I get the actual measurements together later this week. As mentioned, I predict an increase in braking effectiveness of around 10% - so is it worth it for the cost and extra weight, or could the same be achieved just by new original discs, better pads, a good brake service, or even a better vacuum source for the servo!!!

Oh, can you tell I am bored with the Uni assignment I am working on???

[the wombat]

Did a few bits and pieces over the weekend.

- Seat bolster repaired and seat back in
- Wanted to measure the vacuum on each throttle body, but my vacuum gauge was swinging all over the place. So did the butterfly movement by eye and adjusted the linkages accordingly. Ticks over more smoothly now and pick up seems a little more rapid
- I wondered if bleeding the clutch might help with the gear shift, as the fluid looks quite old (grey rather than beer colour). What a PITA. Had to take dizzy cap off, intake hose off, and several other bits and pieces just so I could get a bleed pipe onto the slave cylinder. Even then had to use long nose pliers to get into the space to push the pipe on!!!. Luckily had a long 7mm spanner to reach the bleed nipple. Fresh fluid in the reservoir and clutch, and the gearshift is quite acceptable now. So not planning to change the linkage bushes any more. Will replace the box oil and should be good.

Car already drove well, but every little tweak seems to get more out of it.

[the wombat]

Got a spare set of front hubs sorted this week - new bearings and a splash of paint after a clean up. These are now ready to go on with the new brakes which have also been cleaned up and painted.

Looking through the various bags and boxes of spares I have acquired with each car, I found a full set of superflex bushes for the front suspension, so plan to pop these in when I have the front end to bits.

Apart from that, been spending a few hours working on this:



I bought it because the underside and most of the body are in extremely good condition. No holes, no major rust, just a few dings. Because I have now got the 16v, decided we need to sell something to make sure everything has got dry storage over the winter. This was the one - hard decision as it is a really nice drive (late 8v 1.7 with cat - very torque and laid back).

I have been offered another 16v SW as a swap which is of huge interest, so may not reduce the fleet per plan. Now need to get on and create more garage space!! See where the white door and bin are on the right of the pic. I can fit another 33 in there!!!

[the wombat]

Blue 33 passed its MOT today.

2 advisories, small centre section exhaust leak, and brakes pulling slightly to one side.

Quite pleased with this. Very clean and tidy underneath, and drives nicely although a bit softer than my 16v.

[the wombat]

The swap with the blue 1.7 8v went ahead yesterday, so sidetracked by this although I have finished the big brake work.

I am being a bit lazy and copying this from my post on 155.org, but here are a few pics of the new SW. It looks quite scruffy, but looking around it, its just dust and dirt from storage. A good wash and polish and it should look OK.

It has a few bits of body rust that need sorting:





The windscreen is cracked and needs to come out, so won't be an issue sorting the rust in the top corners. Fuel filler area is perfect, so need to get up into the wheel arch and derust/waxoyl/seal quickly to keep it that way.

I had plenty of time today to get underneath and have a good poke and prod. Bulkhead and floor are very good. Sill seam needs a good cleanup, but I couldn't poke holes in it and the rust is all surface stuff, nothing embedded. Spare wheel tub and boot floor are all good. Suspension, brakes, and lines need refurbing, but the underbonnet area is very clean:


Interior is complete. The carpet is very dirty, but everything is very unworn. I have a spare recaro interior and carpets to go in, so all is fine. Roof lining will need to come out and be cleaned, but is complete and in good nick - very important as its a lot longer than the saloon!!
Overall very very pleased with this. It runs (smells a bit oily so a bit more investigation) but worst case I have a spare 16v lump to go in.
Speedlines did not come with it.
I had a big turnout today to start making space for the barn re-roofing exercise. This SW will have to wait a while, as I want to get on with the S2, so that is now in the middle of the barn so I can move the cars each side out giving plenty of space.




Work on the red saloon is just about done for now. It will get a fluid service before Mallory, and I might get the rear discs in time to fit before then, so next big ticket item for me is the S2 (complete rust free rear quarter cut off another car and on its way to me), finishing the living room (Victorian Parlour) and re-roofing the barn!

[the wombat]

Decided to give the red 16v some love this week.

I was away on a DofE bronze expedition over the weekend helping look after a bunch of students. Some parking up on rough ground dislodged something underneath, so needed to take a look and give the car a good once over.

Well, it was one of those jobs that was planned to take a day but took 3!!

The exhaust was the main cause of the problem, mainly because of very aged rubber hangars. The back box pipe should sit outside the centre pipe and be clamped, but looks like too small a back box has been used, and the pipe is inside the centre pipe, and was free to rotate. Combination of both meant the exhaust had started to sag.

Lambda sensor wiring was also excessive and close to dragging on the ground.

Whilst sorting the above and generally making sure everything was tight and secure, I took a closer look at the OS sill which I had made a hole in earlier. Wish I hadn't as it was clear that it was in poor shape. I took the side skirt off, and made 5 large holes, including pulling the back end and bottom of the arch off (with a big chunk of filler).

New sills seem quite hard to find, so I have chopped out all the rust, and patched everything with 1.2mm zintec plate. Lucky its all under the skirt as my welding is functional but not pretty!!

Pic of all welding done and some masking ready to paint and protect



Finished job ready to put back together:





Protection is:
- zinc anti-rust undercoat
- Plastic seam sealer
- Urethane paintable truck bed liner
- top coat and lacquer (Halfords mix a good match for AR130 Rosso)
- Half a tin of waxoil pumped into the sill

I also took the opportunity to fix the skirt on properly. Drilled and prepped the fixings at the bottom (where the rust came from in the first place), put all the upper fixings in and slid the skirt over them properly, and sorted the end fixings and screws.

Hopefully this will last a while

I also changed the gearbox oil, which has made a bit of a difference, and swapped the plenum and idle control valve as tick over was a bit erratic. While the plenum was off, I set the throttle linkage by eye so both sides open at the same time!!

Overall effect is pleasing. The car runs a bit cleaner, and the gear shift is improved.

A few more things to do before Mallory, including a cold air feed CDA (it has a K&N right above the OS cylinders and exhaust), and possibly rear discs.

[the wombat]

Here is the CDA in place

Really struggled to find a source of fresh air at the front of the car, so the air pipe is now oval and fitted between the radiator and the headlight.

Had to make modifications to the grill by drilling a bunch of holes in the blanked section:

First impressions on driving it for 5 miles or so, is that pick up is a little cleaner, and it revs through a little cleaner, but only very small differences which might be me rather than the car!!

[Integrale]

Nice project's, i bougth me a 33 P4 1. Month ago. Lovely car.

[the wombat]

Any pics? Would be great to see it.

[the wombat]

Been quiet here for a bit, but quick update, been working on the 16v in preparation for the 155 Mallory track day next weekend.

A few things done:
- Tracked down the rear end vibration and sorted
- Rear disc conversion completed. Braking seems nicely balanced without changing the compensator
- NS rear jacking point collapsed while doing all this good stuff. Now repaired, although I really need to practice more welding!
- A little mod to a spare grill to help with the CDA



Not quite lined up due to the rad in the way, but seems to pressurize the CDA with cold air, which is a good thing




Won't be driving like this on a daily basis as looks damned ugly and the grill lacks the proper clips so is cable tied on (love that person who invented the cable tie), but for the track day, should do the trick.