Thanks, Ivan.
The reason for the question was that I have been reading old ROC newsletters from 1994-1997. Early in the life of the Sabres build history the clubs technical rep and the manufacturer (John Barlow) thought that the standard ARB was deemed to be too stiff and recommended grinding some flats on the ARB to reduce its torsional rigidity. That was until in 1997 when one builder who had followed this advice (in the build manual!) had his car fail its MOT as a deliberately modified ARB is (or was then) a failure point.(This was pre-SVA when cars needed to be MOT'd before registration) I haven't found the end of the story yet but in 1997 the ROC technical advisor and the RMC withdrew this recommendation. Luckily the original builder of my car had not modified the ARB.
I think I'll stick with what I've got until I get the car on the road when I can see how it handles with the the weight of the BMW engine.

(small) Progress Report...
 

There doesn't seem to many build reports on the forum at present and my progress is not very exciting but here's what I've been up to over the last couple of weeks.
I spent a not very exciting day cleaning up the rear brake caliper carriers. They were badly painted by the original builder but had also rusted!! I had to start with some old fashioned paint stripper and then cleaned all that mess off followed by de-rusting and cleaning up with Scotch brite and lots of elbow grease.
I then gave them a coat of Hammerite Smooth and left them in the greenhouse to bake hard.

https://farm1.staticflickr.com/469/2...99391aef_z.jpgRear brake caliper carriers by marlinpeter, on Flickr

I have bought some Pagid recon brake calipers as I didn't fancy rebuilding the old ones because the Sierra calipers have a fiendishly complicated handbrake mechanism which, despite being well described in the Haynes manual, still looked like a potential nightmare. The calipers are very pitted and must have been very rusty before being recond but do have new pistons fitted. They came painted but a bit thin so I couldn't resist giving them an extra coat of paint.

https://farm1.staticflickr.com/277/1...792d1739_z.jpgRear brake calipers by marlinpeter, on Flickr

And I bought a new set of sliders and dust covers....

https://farm1.staticflickr.com/345/2...6177b337_z.jpgRear brake caliper sliders by marlinpeter, on Flickr

I've also started installing the brake lines. I'm using Automec Cupro Nickel tubing. I was worried that this would be more difficult to flare than pure copper but it turns out is very easy to bend and flare.

It sounds strange but I started in the middle of the car and will work back and forward from this point. First up to be fitted was the Ford rear brake deceleration valve.

https://farm1.staticflickr.com/348/2...c97a98c3_z.jpgSierra deceleration valve by marlinpeter, on Flickr

The rear brake deceleration valve reduces brake pressure to the rear brakes under deceleration force. It's supposed to stop the rear brakes locking up when braking hard. There is a heavy weight inside that slides forward shutting off the supply to the rear brakes. The short rubber hose is just for protection.

I then had the challenging task of bending a length of tubing to follow the path back to the two way splitter that divides to the two rear brake calipers.

https://farm6.staticflickr.com/5617/...a510d6d3_z.jpgRear Brake line routing by marlinpeter, on Flickr

https://farm1.staticflickr.com/426/2...1443b157_z.jpgRear brake line to splitter by marlinpeter, on Flickr

The original builder's mounting position was a bit high and made the right angle out of the top a bit challenging. (Having now studied this photo, I think I'm going to move the splitter down a bit.)

Well that's all for now and unfortunately I've embarked on repainting all the window frames on our 17c cottage, so car building will be limited to spare time when it's raining :wink:

...peter

Looks like you'll have plenty of time on the car this weekend then, Peter. :)

Progress report....
 

Yeah, the rain over the past few days means I've been able to crack on with the brake installation.

But firstly, I've had a new handbrake cable shortened by Speedograph Richfield. Excellent fast service including test certificate (COC). I've had it shortened by 750mm as specified in the RMC build manual for a Sierra cable.

https://farm1.staticflickr.com/686/2...36957659_z.jpgShortened handbrake by marlinpeter, on Flickr

The new termination is slightly different to the original but seems to fit and work OK.

https://farm1.staticflickr.com/672/2...8e204356_z.jpgShortened handbrake by marlinpeter, on Flickr

So on with the rear brakes...

https://farm1.staticflickr.com/725/2...52d98a14_z.jpgCarrier, slide pins and new disc by marlinpeter, on Flickr
https://farm1.staticflickr.com/663/2...78bc7fca_z.jpgBrake pads by marlinpeter, on Flickr
https://farm6.staticflickr.com/5828/...8a072e36_z.jpgCaliper installed by marlinpeter, on Flickr
https://farm6.staticflickr.com/5642/...a7a7c4ca_z.jpgRear nearside brake by marlinpeter, on Flickr
https://farm1.staticflickr.com/674/2...4d5c7ffc_z.jpgRear nearside brake line by marlinpeter, on Flickr
https://farm1.staticflickr.com/619/2...83396e44_z.jpgRear nearside wishbone hard line by marlinpeter, on Flickr

Now it's back to the house painting....

...peter

Update....
 

My earlier pedal box trials centered around replacing the original Ford Sierra pedal box with a pedal box from a BMW e46. These are nicely designed assemblies but required the modification of the Sabre mounting cross member and the pedal positioning was not ideal. Whilst pondering one day and looking at all the pedal boxes and pedals I have accumulated it occurred to me that it might be possible to mount a BMW clutch master cylinder to the original Sierrra pedal box which was designed for a clutch cable operation. I first removed all the parts associated with the cable connection and some parts of the pedal. I was then able to mount the BMW M/c on two 6mm spacers. (the box section spacers are temporary as I didn't have any suitable round tubing to hand). I also need to make and fit some nylon spacers each side of the m/c piston
eyelet.

https://farm1.staticflickr.com/693/2...fb1608a9_c.jpgClutch Master Cylinder by marlinpeter, on Flickr

My first trial was using the hole you can see furthest from the pivot (red bush) but this resulted in about 5" pedal movement so I drilled another mounting hole nearer the pivot and this gives me about 6" pedal movement which is more in line with a BMW pedal box. Shown hear in the fully depressed mode.

https://farm1.staticflickr.com/578/2...d00d9c37_c.jpgClutch Master Cylinder(down) by marlinpeter, on Flickr

Here the pedal is shown in the rest position. I need to devise and fit some upper and lower mechanical stops to avoid damaging the master cylinder and find a way of adding a return spring but the overall concept does seems to work ok.

https://farm1.staticflickr.com/775/2...e92d3730_c.jpgClutch Master Cylinder(up) by marlinpeter, on Flickr

Because I'm using a remote dual circuit brake servo I needed to find a master cylinder with a fixed pushrod to attach to the brake pedal. This one seems to fit the bill and is from a Triumph Spitfire 1500.

https://farm6.staticflickr.com/5688/...93bffdc8_c.jpgDual circuit master cylinder by marlinpeter, on Flickr

This pushrod extension was provided by Marlin to extend a Metro servo pushrod. I plan to use it to extend the Spitfire master cylinder pushrod and attach it to the Sierra brake pedal.

https://farm1.staticflickr.com/601/2...f6eab3ea_c.jpgMaster cylinder push rod extension by marlinpeter, on Flickr

And like the clutch, I need to add a return spring, etc.

Totally unrelated, I've bought some more seats.....

Slight change of direction. I had already bought a pair of Mk1 MX5 seats but they don't have the shoulder high seat belt supports. My Sabre chassis has rather low seat belt mounting positions that would fail the IVA regulations. The Mk3 MX5 seats have seat belt supports that raise the turning point. I believe the IVA will accept this as a solution as long as the seats are designed to take the forces.

https://farm6.staticflickr.com/5717/...16675030_c.jpgMazda MX5 Mk3 seats by marlinpeter, on Flickr

On first look they look like they will fit OK but I'm not sure the design suits the car?

I've also been able to source a new Granada fuel tank locking ring from a parts supplier in the Ukraine! (autopartmaster)

https://farm1.staticflickr.com/579/2...05903c8c_c.jpgNew fuel tank lock ring by marlinpeter, on Flickr

Isn't the internet a wonderful thing!!

....peter

Pedaling along.....
 

I've finished work on the pedal box.......

The brake master cylinder has been lengthened with the Marlin supplied extension.The Sierra pedal box needs a good clean up and repaint.Pivot bolt needs to be 10mm longer.

https://farm1.staticflickr.com/582/2...c7f7092f_c.jpgSierra Pedal box and master cylinder by marlinpeter, on Flickr

This is the Triumph Spitfire 1500 brake master cylinder mounted to the Sierra pedal box. The 3.5 mm hardboard is simulating the GRP bulkhead on the Sabre body tub. The 6mm thick MDF disc will be replaced with a 6mm steel disc.

https://farm1.staticflickr.com/567/2...26a8bea1_c.jpgBrake Master cylinder by marlinpeter, on Flickr

https://farm6.staticflickr.com/5747/...5e0363ca_c.jpgSierra Pedal box and master cylinder by marlinpeter, on Flickr

Alignment is looking good but the pedal box could do with moving up about 5mm in the final solution.

If fitted return springs to both the clutch and brake pedal.
This is the brake pedal with a BMW spring.
https://farm6.staticflickr.com/5779/...ed1ef1d7_c.jpgBrake Pedal Return spring by marlinpeter, on Flickr

https://farm1.staticflickr.com/730/2...a3462058_c.jpgClutch Pedal return spring by marlinpeter, on Flickr

The clutch spring is a Rover part found in my box of bits.

Modifications to the Sierra pedal box are now complete so it's now stripped down for a repaint.

https://farm6.staticflickr.com/5645/...ee9772f2_c.jpgPedal box painting by marlinpeter, on Flickr

....peter

As always, you are doing a beautiful job.

Thanks Amir, your feedback is always welcome.

totally agree with Amir. It's a pleasure to see progress every time I log in. Properly well-thought-out care and attention to every detail - marvellous!

Glad you're enjoying the updates, here's the next one........

The Spitfire brake master cylinder pre-dates the introduction of brake fluid low level warning light switches. The BMW cap has a switch but the thread is different to the Spitfire reservoir. Luckily the BMW cap is made with a separate locking ring so I was able to cut a hole in the Spitfire cap.

https://farm6.staticflickr.com/5798/...6f712265_c.jpgBrake fluid level switch by marlinpeter, on Flickr

https://farm1.staticflickr.com/639/2...07f5ee27_c.jpgBrake fluid level switch by marlinpeter, on Flickr

My thoughts have now turned towards the exhaust system. Re-use of the e36 donor exhaust system has a number of benefits in terms of being matched to the engine, emissions, sound level and cost. So I've positioned the exhaust under the car to take a look at how it looks. The good news is that it starts on the right side of the car and ends up with the rear box in roughly the right position.

https://farm6.staticflickr.com/5652/...666d21f4_c.jpgExhaust initial trial by marlinpeter, on Flickr

The rear box is in, roughly, the right position and is clear of the rear suspension and fuel tank.

https://farm1.staticflickr.com/661/2...0e7f5b71_c.jpgExhaust initial trial by marlinpeter, on Flickr

Rear box currently projects about six inches from the rear chassis rail. The Sabre rear bumper sits about 3" from the rear chassis member so I need to loose about 3" in the overall length.

https://farm1.staticflickr.com/652/2...9748aaed_c.jpgExhaust initial trial by marlinpeter, on Flickr

The Cats sit centrally below the prop shaft tunnel

https://farm6.staticflickr.com/5832/...e67859b4_c.jpgExhaust initial trial by marlinpeter, on Flickr

I need to design a central support for the system to hang from. (It's currently hanging from that bit of blue rope).

https://farm1.staticflickr.com/590/2...ce0d68e5_c.jpgExhaust initial trial by marlinpeter, on Flickr

The front pipes to manifold is the biggest issue. With the exhaust slung under the chassis rails it is approx. 7cm too low to meet the manifold. I plan to try some jetex bends to raise the pipes up to the manifold.

https://farm1.staticflickr.com/644/2...a9963878_c.jpgExhaust initial trial by marlinpeter, on Flickr

Next step is to order some Jetex bends and joining sleeves.

...peter

Just a thought, but you say your back box needs to be at least 3 inches in/shorter than its present position and your down pipe to exhaust is 75mm a drift? Would it not be possible to cut the 3inches out of the straight pipe and then attach/ lengthen the upturned front section by 75mm, I am joking with the metric imperial but serious about a cut shutvand lengthen. Actually surely it would be possible to alter the bend at the front to get the length to down pipe and that would also solve the long back box problem too. Ed

Hi Ed,
yes, thanks for the suggestions. I've been looking at these kind of options but BMW have built in some complex curves and bends that are not simple to cut and extended. (And difficult to photograph as well!) I'm sure if I had a very large tube bender and mig welder I could make something fit but I don't so I'm going to try and make some standard Jetex parts fit. It may not be very pretty but so long as it's gas tight I'll be happy.

My first cuts were to remove the only straight section of the rear section.

https://farm1.staticflickr.com/606/2...70e9de6e_c.jpgExhaust shortening by marlinpeter, on Flickr

https://farm6.staticflickr.com/5682/...1f3fa7eb_c.jpgExhaust modification by marlinpeter, on Flickr

These appear to be very small silencers, presumably designed to remove a particular frequency. I used a slitting cutting disc in an angle grinder. It was re-assuring to see how thick the pipes are.

I then rejoined them with some Jetex joining sleeves....

https://farm6.staticflickr.com/5816/...ee81fe9e_c.jpgExhaust shortening by marlinpeter, on Flickr

Cut sections re-joined with Jetex double ended sleeves. Plus 48->50.5mm spacers used to match the pipe sizes. These will be sealed with exhaust assembly paste when finally aligned.

Next, I've removed the front section to manifold pipes....

https://farm6.staticflickr.com/5741/...47e12d0c_c.jpgFront Exhaust modification by marlinpeter, on Flickr

The first step in modifying the front exhaust section was to slice off the front manifold connection bends to insert an 'S' bend made up of two 45 degree bends. I can't imagine why BMW built the exhaust with one pipe 46mm diameter and the other is 50mm?? Luckily Jetex do 46mm and 50.8mm bends and packing sleeves to convert from 50mm to 50.8mm.

Now I need to re-assemble the front and rear sections and offer it up to the chassis to see where I need to cut next. My current plan is to now get the rear box mounted in the right place and then try and sort out the front pipes to fit.

(I say'my current plan' because I often plan something in my head and then do it different when I get working on the car. I guess my brain is not very good at 3D modelling :shocked:)

...peter

3D imaging of your build
 

Looking at what you have done and are doing, I recon your brain works fantastic, your 3D visualization marvelous, and planning second to none. I am yet to meet a more meticulous car builder. Keep up the good work Peter.

I while back I fitted these Volvo engine mounts.....

I've now replaced the temporary square washers with bespoke spacers discs that help to spread the load correctly. (they will be painted before final engine fitting)

https://farm1.staticflickr.com/600/2...b83a62e7_c.jpgNearside engine mount by marlinpeter, on Flickr

https://farm6.staticflickr.com/5792/...746eabbf_c.jpgOffside engine mount by marlinpeter, on Flickr

I've also slotted the engine mount chassis holes by about 10mm which means the mounts now sit better on the chassis mounts and has also solved the sump to chassis clearance issue.

I'm now happy (subject to another body tub check) that the engine and gearbox are in their final position.

....peter

My current focus is on fabricating some brackets to support the rear exhaust silencer box. It's become a bit of a challenge as one of the brackets needs to go under the spare wheel well. I'll grab some pictures when I've finished....

But in the meantime here are some pictures of the rear brake line, from the rear brake compensator valve up to the servo, that I fitted a couple of weeks ago.

https://farm1.staticflickr.com/563/2...1c270c7d_c.jpgRear brake line by marlinpeter, on Flickr

https://farm1.staticflickr.com/630/2...7566c812_c.jpgRear brake line by marlinpeter, on Flickr

https://farm6.staticflickr.com/5756/...54e29926_c.jpgRear brake line to servo. by marlinpeter, on Flickr


...peter

Exhausted.....
 

I've continued working on fitting the exhaust system over the last couple of weeks. It's been a lot of trial and error trying to find the best location.

So firstly, here is the rear silencer box clamps and hangers...
This is the nearside mounting. I've used standard BMW style silencer clamps and hangers. The hanger is bolted to the Sabre's exhaust mounting point and the rear chassis rail.
https://farm6.staticflickr.com/5711/...dbcd0853_c.jpgRear Silencer N/S hanger by marlinpeter, on Flickr

The offside mounting had to be bit more complicated as it has to hang from the rear chassis rail and clear the spare wheel well in the body tub. I modified the silencer clamp but the hanger is standard.

https://farm6.staticflickr.com/5754/...99b86d0c_c.jpgRear Silencer O/S mount by marlinpeter, on Flickr

BMW style clamp had to be modified to get the hanger low enough to clear the spare wheel well.

https://farm1.staticflickr.com/743/2...06782d1f_c.jpgRear Silencer O/S mount by marlinpeter, on Flickr

Here's a view from under car. The cut in the angle bracket will be welded to stop it flexing if this design is successful.

https://farm6.staticflickr.com/5804/...c2971486_c.jpgRear Silencer O/S mount by marlinpeter, on Flickr

It was then on with making something to support the middle section of the exhaust system.....

https://farm6.staticflickr.com/5654/...d51916ee_c.jpgMiddle Exhaust system hanger by marlinpeter, on Flickr

The hanger slots over the seat belt mounting rails. I didn't want to drill holes in the rails for fear of weakening them. The hanger bracket will be welded to the rails once I'm happy that it doesn't foul the body tub and I've finalised the front to back location of the whole exhaust system. This is the third version of this bracket so I hope it is the final.

The upper mounting rubber brackets are standard BMW parts bolted to the hanger with M10 bolts and thick walled ali tube spacer.

https://farm6.staticflickr.com/5636/...92448755_c.jpgMiddle Exhaust system hanger by marlinpeter, on Flickr

View from under the car.......

https://farm6.staticflickr.com/5732/...6dcf5a08_c.jpgMiddle Exhaust system hanger by marlinpeter, on Flickr

I've also added an extra support at the front of the 'cats' as I will be using flexi pipes between here and the front down pipes so the weight of the 'cats' can no longer be taken by the gearbox mounting bracket. (the idea of two 45 degree Jetex bends didn't work :sad:)

https://farm6.staticflickr.com/5682/...22143cc4_c.jpgExhaust System - front mount by marlinpeter, on Flickr

It's fixed to the gearbox cross-member chassis rail with an M8 steel rivnut. The angle bracket is fixed to the exhaust pipe with a standard exhaust clamp. (The M8 bolt in this shot is too long and will be replaced when I get some the right length!)

https://farm1.staticflickr.com/681/2...a54e5a04_c.jpgExhaust System - front mount by marlinpeter, on Flickr

Next, I've ordered some flexi pipes to join the exhaust system to the down pipes from the exhaust manifold.

After I have finished fitting the exhaust system, I plan to refit the body tub again to check all the clearances between the tub and the fuel, brake lines and the exhaust mountings, etc. Fingers crossed that there won't be too much re-work needed :noidea:

.....peter

Hi Peter,
I think everyone following this build are enjoying your progress and the way you come up with solutions to any problem you face during your build. I have an idea about the bracket you have put over the seat belt mounting rail. Rather than welding the bracket and making it permanent, how about making a same shape but smaller bracket to fit from underside of the rail and bolt it to the top one with the rails sandwiched in between. This would make the bracket adjustable, forward and back, and no welding to the rail would be required.

Hi Amir,
thanks for the feedback, I think that is great idea! It also means it could be completely removed should I ever need to change the type of exhaust.
cheers, Peter

I am glad you liked the idea. But to be able to remove the bracket without having to take the body off the chassis, it will be a good idea to have the lower one in one piece but the top one cut in the middle and each half to have its own bolt to secure it to the one below.

You're right again....

Looking at this picture again, I certainly need to check the options with the body tub on, which was my next step...and I think I need to install the propshaft to check clearance.

https://farm1.staticflickr.com/558/1...a9a1eef7_c.jpgFuel/brake line planning by marlinpeter, on Flickr

I think I spoke too soon as I think version 4 may be next.....

(that will be after I've fixed my daily drive that has sprung a leak from the HP diesel pump :doh::doh:)

cheers, Peter