Porsche brake conversion Pt3

I think I've been a bit sidetracked sorting out the brake conversion instead of getting all the welding completed, probably because it's more fun seeing shiny bits coming together.

The problem with the rear disc diameter being too small was solved with replacing the 944 >88 discs (289mm diameter) with 944t (928s2/928s4) 299mm diameter ones, these new rear discs are a little thicker at 22mm making it a squeeze fitting the caliper when they have new pads. The new disc cost an extra £30 a pair; this reminds me why I have a Vdub and not a Porsche.

The caliper is a pretty tight fit in the back off the 15" wheels; there is a slight rub on the wheels' inner shoulder where it rubs on the front caliper face so I'll need a wheel spacer of about 6mm to get the minimal clearance all around. It's not what I wanted to do. But it's something I'll have to live with.

Trying to find 14mm washers in the local DIY shops to use as wheel bolt spacers was harder than expected so I've resorted to using 15mm plastic water pipe. I first cut them 7mm thick that didn't work, then at 9mm and this still rubbed in a few places on the inner wheel, This meant pushing the wheels this far from the hub gives me the next problem of having to use longer wheel bolts, so I may just space the wheels enough to get to get 4mm spacing from the caliper keeping enough thread for the wheel bolts and clear the small amount of material from the caliper to clear the foul.

I popped down to a local Porsche show room in my bug to collect some caliper mounting bolts, after a scan of the 911,s I was greeted by a pretty lady behind a desk asking if I would like any help, explaining why I was there and a phone call later a suited gentlemen arrived with my £6 bag of bolts, a little surprised I paied and started to ask about caliper piston sizes and brake master cylinders, "sorry I don't study the breaks" silenced I decided it was time to leave. You can't beat speaking to a grubby mechanic who knows there way around the cars they work on.

With new bolts I mounted the front caliper to the wooden bracket I'd made and with the bearing spacers fitted I was able to work out that I needed 11mm offset to centralise the caliper on the disc. I'll now have this bracket machined once I decided the best place to position the caliper around the spindle. Although I'm still unsure if I should use my link pin or ball joint spindles and beam.

Porsche brake conversion Pt2

After all the previous measuring I realised that using only one spacer behind the inner bearing to take up the 8.5 mm lateral play would push this bearing off the flat running surface and over the tapered portion of the spindle, so I decided to (ask my kind, old school engineering uncle with cool 40 year old tools, at the cost of a portion of fish and chips to) turn down the inner spacer 6.5mm thick with a taper to allow for the spindles' inner radius. This slid on with a slight tap and allowed the inner bearing seal to sit on the original face and gave me a gap of 9mm behind the disc to fit onto the original wheel cylinder mounting holes a mounting plate for the calliper.

The vision of a shiney Fusch wheels and polished callipers isn’t as easy to pull off as “oh you need some 944 hubs to do that” Its hard to get the right parts when you don’t know the model and year of the car, you cant just ask for a rear disc with about this much diameter and the depth to fit the rusty hub you plonk on the counter, But the bloke at the parts shop was intrigued with what I was trying to do and was very helpful pulling parts off the shelf’s till I found what I thought would fit.

I like (more stare at each time I see one) the 996 / Boxster style of Porsche mono block (all once piece) callipers but these are for 320ish mm diameter discs to fit 16”+ wheels and would be to much trouble to fit in my 15”ers So the power of eBay drew me into it's grasp for a month while I tried to obtain a set of 944/924 Brembo callipers for a fair price (Inc postage). Of course the description is not always accurate. What I received needed a full check up. this included freeing a couple of pistons new dust seals and some corrosion treatment.

During my clean up and inspection it became apparent I'll have to sort a few things out. There was corrosion around one off the pistons holes that will need blasting to remove it and that piston was seized, this was because of corrosion on the surface. I found out after I levered it out that there’s a removal tool that probably makes the job a lot easier. Also the piston sizes weren’t matching and the rotation arrow was the same. Each calliper is manufactured with two different size pistons, the smaller of the two at the leading edge. I ended up with a pair of 36mm-40mm that Ill use for the front but have a right hand 32mm-36mm and a right hand 30mm-34mm. This is the problem of doing things on a budget, you get what you pay for. I'll look for something better later but for now they will help me get everything fitted OK.

Fitting the calipers’ to the rear 924 swing arms should be a bit easier than messing around with bearing spacers. With new discs trialed on and the calipers pads centered on these, I’m able to work out the spacing between the original caliper attaching threads on the rear swing arms and the calipers. If I sit the caliper so the pads are on the center of the disc it foul's the disc on the lower part of the caliper, and because the rear hubs came with out rotor attaching parts (two counter sunk disc fixing screws) Ill need to sources these to get the disc fixed securely so that the measurements I need to adjust the caliper are correct.

If I fit the caliper to the original mounting threads on the rear swing arm the pads over lap the disc. The easiest way to solve this is hope there a wider disc with the same offset for the hand brake drum assembly. I think the Brembro calipers are fitted to turbo 944 so that could be an option, although that may mean a bigger disc off set for larger turbo style wheels. I'll have to have a chat with the parts shop again and see if they have any thing that will help.

Grabbing a few spare bit of pallet wood I knocked up a front caliper mounting bracket this gives me a visual idea of the calculations and drawings I've been spreading around the garage on each piece of scrap paper I could find, With a bit of fine tuning. I'd like to get this part CNC (Computer Numerical Control) machined at a local shop, but if its to expensive Ill make it from plate steel and weld on and tap the spacers/ mounting holes. All of this and I still need to work out how to pressurise this lot? I'm sure the original single circuit master cylinder wont be up for it!

Front Valance Pt3

Well back to the job of repairing the front valance again. I’ve been going back and forth to this job for too long now and I decided to post the work once compleated..... ish. With the joining brackets fabricated I set up my new 160 amp welder to fit these on. Wow how much easier it is to weld with decent kit (although I’m still not perfect), the small old hobby welder I’ve been suffering with will defiantly get the boot. The bracket was tacked on with ease and the lower flange I decided to bend to the profile of the closure panel when its trial fitted.

I drilled and tacked some nuts inside the valance for attaching the cab floor belly panel because unfortunately this panel didn’t have the forming for these, I then trialled the valance front closure panel using the lines drawn on tape Id marked as a datum long; long ago. With a bit of forming at the ends and re-measuring, the panel went on with no problem. I tacked the lower part from the inside the valance and discovered the joys of welding upside down. The welding burns are a lesson learnt, and it could get hot and sweaty stuck in a garage with all that protective gear now the summers coming.

I received the new lower front panel (which I specially requested without the cut out for the nose and longer at the ends so I can fold it over like the original.) Rather than butt weld this panel I joggled a small lip on the repair panel to sit inside the original one. I ground a ton of filler off the front panel so I could ensure the repair panel was straight, although a bit tricky around the nose; using some fabricating magnets and clamps the panel fitted OK.

Eager to get the panel on I started tacking it together, then double checking the fit before I went welding crazy I noticed that the joggle at the left corner end of the panel was overlapping to much, and causing the curve of the panels not to sit flush. Access to the back of this panel is very awkward because of the front light bowl and inner kick panel, this ruled out any fabrication from the back. So I painstakingly cut the joggle off from the front with a cut down junior hacksaw clamped in a pair of pliers. This did the job of letting the pannels sit flush, and then with the magnets in place I continued to tack it all together.

Learning from my cock up with warping the dog leg panel I spaced out the weld points and spot welded the a seam between the two panels with only a second spent on each weld, but still the original part of the panel had a slight ripple along its curve. Not sure if I’m being to particular about my work or still have a lot to learn but I'm determined to get it right. So I guess Ill rely on the paint prep to get rid of any imperfections (filler).

I cleaned up the welds and with a few tacks along the lower lip and tidying up the wrap around part of the edges this job is finally finished.

front door hindge replacement

So that when I weld the wheel arches in place I get a true line to compare against the door bottoms I’m replacing all 4 front door hinge pins. The doors had only dropped a little from the 40 years of wear, but this movement transferred to the end of the door meant the door bottom scrapped on the arch when you closed it. One of the mirror stalks from the top hinge was welded to the top. This was a quick fix to stop the wear getting to bad, but means I needed to carefully cut off the stalk and grind off the weld to free up the top of the pin. I first tried to squeeze the pins out with a G clamp and small socket hopping the pins would be louse enough to pop out. But quickly gave up to getting the flame thrower out. I’ve been reluctant to attempt this job because of the fear of it turning into a nightmare and ending up damaging the hinges or even worse the doors.

With a fire extinguisher and bottle of water close by and some help from a friend we got the plumbers torch lit and started heating up each hinge. I concentrated the point of the flame only on the upper and lower parts of the hinge as these are the parts that secure the hinge pin in place. After about 3-4 minutes of heat applied evenly on both sides top and bottom, we rested the hinge against a vice and persuaded/eased/whacked the pin out from the lower side. For the first attempt I wasn’t properly prepared, I bent my first punch and lost the heat only getting the pin out half way, The next attempts using a cut down allen key were surprisingly easy, with the pins sliding out and we managed not to scald the doors or burn down the garage.

The next task is to replace the pins and do some thing about the cracks around the hinge rivets. The new upper replacement door mirror arms are 8.5 mm over size, and the lowers are 8mm. my first mistake is presuming the lower pins wont be that worn. The new lower pins slid straight into the hinges and wobbled, so I'll have to replace the 8mm’s to 8.5’s. This had held me up till I can replace these.

Some time later...... Now with replacement 8.5mm bottom pins and access to a pillar drill I was able to ream the hinges to a tolerance fit. This was done with an adjustable reamer, not my first choice but because I was messed about getting the correct size originally this got me through. Adjustable reamers are not the most accurate to use, it took a bit of trial and error to get the exact fit I required, and each pin had a very slight size variation and tapper that effected a tolerance fit.

Porsche brake conversion

Helpfully link below from Vdub engineering
porsche-brake-conversions technical info

After having a bit of a break from welding up the van, I spent a few late nights on the net working out the best option for the wheel and brake set up that I'd like. About 10 years ago I bought a set of 15"x6" Porsche Fusch alloys, I later found out from a friend that the guy I bought the wheels from had said they couldn’t be fitted to a van. Well, with that in mind, I saw it as a challenge. There’s been plenty of bolt on products and fitting kits on the market since then. Some are good quality, some well over priced and others not quite the look I’m after. I’ve decided to try and save a bit of money by getting good quality parts by sourcing all my own, this will mean hunting for the bits I think Ill need and a few modifications here and there. I hope my discoveries will help anybody else trying to fit Porsche brakes. After reading a few split screen van club forum discussions and a few tips from members, I’ve started by getting hold of a set of front and back Porsche 944 hubs (non turbo) and rear swing arms. This will allow me the choice off aluminium arms or the VW type 3 set up I have had laying in my garage. But that decisions for later.

I’ve stripped the Porsche spindles to work out bearing sizes and spindle lengths, I also have a choice of which spindles to try and fit the hubs too.

• Split 1964 king and link pin drums.
• Bay 1968 ball joint drums.
• Bay 1971-ish small stud Pattern discs brakes.

I spoke with Paul at T3D who along with other bits of advice recommended fitting my king pin set up back on the bus replacing the current ball joint beam I replaced years ago from a scrapped 1968 Bay, as it was cheaper then than getting my original link pins overhauled. This is no longer the case as scrapped Bays are harder to find and link pin referb kits are a lot cheaper. Stripping and comparing the parts, to my surprise the spindle diameters are the same, just the length is different, and sliding the hub on to the spindle with the 944 bearings in the hub I could work out what thickness spacer Ill need for the rear bearing.

Front Valance Pt2

Getting back to finishing the front valance with a hope to get it wrapped up in a weekend was a bit hopeful. I should have learnt by now how long things take .

The left hand lower portion of the A pillar was as rotten as the right hand side so this was removed, keeping the original radius just below the hinge bolts to help blend the seam of the weld . Again most of my time was spent cutting and filing the two repair pieces and trying not to rush ahead and grab the welder out.

The inner valance was then trial fitted up with only a little trimming required. Using the bumper mounts as a guide I was able to line up the bumper mount holes, and then clamp the valance into position. With almost no gap between the panel and the forward chassis faces, this allowed me to drill spot welding holes at the original positions that I had grinded off keeping a good gaping and shape for the cover panel.

I secuired the clamps close to each hole trying not to weld the clamp to my van, this was to ensure a tight fit onto the front chassis supports. A few more spot welds to attach the top of the inner panel to the cab floor and this panel will not be going any where fast.

To finish the ends I kept the panels I originally cut off to use as a template, this turned into more of a guide. These panels I hope will be a little stronger that just welding a piece of angle in the corner, they also help with the profile of the outer skin, because the new valance curves in to steeply to match and support the front skin profile ill use these to weld the skin onto at the ends.

I was then able to trial fit all the other closure panels and found that the cut out for the nose, on the lower front skin does not match the correct profile! When the panel is at the correct height (by my calculations and measurments) it does not reach up to the lower portion of the nose either. Frustrated and just wanting to get this done I was tempted to just patch up the gap, but a short break from the cramped garage and a quick sugar rush I deciede to return the panel and get one made with out the cut out, Replacing this panel would also help as the original panel was too short to wrap over seam at the ends as origenally manufactured.

front window gutters

So far all the jobs I've tried to start have been held up or I've had to stop because of not having the right parts or bits need modifying. Hopefully patching up the front windows shouldn’t be such a problem.

Nope, think again.

Ordering parts on-line means you can’t see how how good the parts are untill you get them on the van. Nearly all the panels I've tried to fit need fabricating, so learning panel beating skills is becoming a necessity. I started repairing the window gutters with two corner repair panels, but trial fitting these panels and I found they didn't meet in the middle. I had a word with Schofields at a show and they made me up a pair of gutter that would stretched the whole length of the window frame and bend up enough to cover up the holes I’d already cut out.

A job that I thought would take a day, had taken that long just to get the area and parts cleaned, cut and filed to fit. This included picking away the sealant that I'd originally used under the windows, to stop rain comimg through the rust holes and filling up the van. When this repair is done I hopefully wont need a towel by my feet any more.

Before I got the gutter welded into place, a few bits of the dashboard lip needed patching up, and one of the new gutters repair panels needed cutting and splicing back together, because it was a couple of milimeters too long. With a lot of patients and a brand new light sensitive welding mask (well worth the money £80), I managed to get both gutters tacked and welded on the second day. After grinding down the worst of the welds, I used a large dreadnought file to clean up the front radius, this gave me a flat and even finish compared to rotary file or sanding disc, any remaining pits I re-welded and filed down again. A final rub down and a coat of primer and this is the vans first completed repair.