Historic Forest Stage Rally 124 Spider

Non-engine, eg: aerodynamics, gearboxes, brakes, suspension
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Wed Sep 18, 2013 8:27 pm

Well after a very long time of not doing anything on the car, I have at last got some work done, but seem to have a problem.
I have finally fitted the fuel lines through the car and mounted the pumps and filter king in the boot. The tank if finally fitted so I can now complete the rear wiring etc.
Wanting to see some external progress I decided to start fitting the front suspension. Most things started to go together well. I wanted to try my new front spring compressor. This was something shown to me by Mick Woods and was used by the works teams. Nothing too fancy just a piece of 16mm high tensile screwed rod, some long nuts, and most importantly a couple of thrust bearings. The bar passes through the shock absorber hole and a plate that is inserted in the spring. The screw is tightened and the spring compresses against its seat. The lower wishbone is then fitted and the spring released. I was most impressed. It worked really well. I think it would also work with an impact wrench or possibly an air ratchet it is that easy. When I fit the other spring, I will take a few photos. Anybody know of a hydraulic compressor that works? I have one but it wont fit.
Having fitted one spring, I decided to carry out a few basic checks on the other side. My front suspension is taken from my old rally spider. The wishbones are strengthened, and I am re fitting the Abarth front tie rods. I have attached the Abarth info sheet showing the rods. ( I would think the copyright has expired).
front tie rod 1.jpg
Abarth info sheet
front tie rod 1.jpg (545.86 KiB) Viewed 1907 times
These fit to a mounting added to the lower wishbone ( shown as point A on the diagram. ) The front is mounted to the additional front cross member added which is also the sump guard mount. All of this has been assembled onto the new car.
I assembled the wishbones on the near side without the spring. I then added the 124 hub and measured the amount of movement at a point on the edge of the lower wishbone. I then changed the hub to the 125/Argenta hub, and again took measurements. ( These fit in to the common conception that 15 mm has to be removed from the standard bump stop) So far so good.
I then attached the front tie rods. These have left and right hand threads at each end so can be adjusted. The problem is they don’t seem to work. You will see in picture 2 the how the tie rod fits to the front additional cross member and the lower wishbone.
front tie rods 3.jpg
Front tie rod mounted
front tie rods 3.jpg (635.37 KiB) Viewed 1907 times
The problem is that when tightened up the lower wishbone will not move.
lower wishbone 1.JPG
Lower wishbone
lower wishbone 1.JPG (788.96 KiB) Viewed 1907 times
Having slackened everything off what seems to be happening is that the pivoting arc of the tie rod is not the same as the wish bone. This now seems to be quite obvious, but what I don’t understand is that it worked on my previous rally car for 3 years. The one thing I will say is that the original rose joints always had a lot of play in them ( I was rallying on a budget and could not afford to change them so put up with the noise- this was back in 1983)
Having now studied the situation and taken a few more measurements I have come to the conclusion that the tie rod moves in an arc that is 3.5mm longer than the point it is attached to on the lower wishbone. ( See calculations sheet) .
wishbone measurements and calcs.jpg
Calculations
wishbone measurements and calcs.jpg (326.93 KiB) Viewed 1907 times
I have taken measurement and can conclude the following
Wishbone length measured from pivot centre to end of wishbone = 265mm.
Travel of suspension at this point = 150mm.
Position of mounting point for tie rod on lower wishbone from pivot point = 195 mm
Length of tie rod when connected in centre of suspension travel = 340mm

Tie rod front member mounting is in line with lower wishbone pivot point.

Now, if I bolt everything up, at the centre of suspension travel (for theoretical purposes) the tie rod would move the lower wishbone backwards or forwards by 1.75mm at 195mm from the pivot point. This movement would strain the inner wishbone mounting rubbers. (I could calculate by how much) .
My question is this how they are supposed to work? Could it be that the suspension would normally move more than this in any case?
The only difference in the suspension from my old car is that the rose joints on the tie rods are thicker. I have put the old worn rod ends on and they still show the same movement. The suspension works as there is so much play in them. The mounting point for the front cross member is the same. An interesting point is that when the sump guard is mounted, then the additional cross member is also fastened to the engine cross member, making a very stiff mounting for the tie rod/lower wishbone. Is the CS chassis different to the BS? Everything measures the same and thew parts I have seem to all fit ( wishbones, engine crossmember, antiroll bar , etc.)

The other consideration is the suspension travel /ride height on the new springs. Unfortunately this wont be known until the car is finished. However, I may need to take numerous measurements so that I know what length to set the tie rod to. After all this worry it could be that I just bolt it on when the car is finished and on the ground and it will work (as it used to) but I would rather fully understand the logic.
What am I missing? ( apart from brain cells)
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Tue Jan 07, 2014 1:50 pm

Well after a spurt of work in the early summer the Rally Spider work came to a halt. Paid employment got in the way and a few other things. Anyway, over the last month I have made some progress.
In my last post I mentioned about the front tie rods and how they appeared to lock the front suspension. Further investigation and calculations leads me to believe that they are supposed to do this.
If you calculate what happens, the new tie rod will pull the bottom wishbone forward as the suspension compresses. Now this may seem a bad thing, but if you calculate how much the wishbone actually moves ( on rubber inner bushes) then it is in the region of 2mm total. I suspect that this movement is far less than would happen if you hit ruts at speed without the tie rod. Anyway- we will try it when it is up and running.
The next issues were the brakes. We finally measured up the front brakes and designed a mounting plate. ( For Porsche 911 callipers).
front brakes v 1.jpg
Front brakes parts - attempt 1
front brakes v 1.jpg (179.11 KiB) Viewed 1845 times
It was made at a local machine shop and Pete(my co driver) and I were excited about mounting the brakes. Some plans do not go right. We fixed all the hub ( Fiat 125), calliper and vented disc onto the car. 30 mm hub adaptors fitted and the 13” wheel fitted a treat. We were well chuffed until we tried to turn the steering. Unfortunately we had not noticed that the calliper will hit the lower wishbone on full lock. ( This is with the calliper mounted along the centre line to the rear of the car. ) I believe this is how the works cars had them, but they are Abarths with the modified lower wishbone. ( Is that one of the reasons they did it?). We believe the solution is to move the calliper up by about 15 deg. We should get the new mounting brackets this week.
The rear brakes have been a nightmare. These also are Porsche 911 (rear) callipers. Again originally mounted on the independent rear end, not a live axle. (Live axle cars had twin callipers one of which was a 3 pot Fiat 2300 calliper. ) The problem is that current rally rules state you must have a mechanically operated hand brake to conform with vehicle use regs. ( Even though period rally cars did not have mechanical hand brakes only hydraulic). I have considered many different options, from using specific hand brake callipers to just using standard rear discs- just to get the project moving forward again.
I purchased Wilwood spot handbrake callipers. These will do the job, but not with 13” wheels. I am sure a suitable bracket could be made, but it would take very complex machining /fabrication. With larger wheels (14 or 15”) they would be fine.
spot caliper.jpg
Wilwood Spot caliper
spot caliper.jpg (99.62 KiB) Viewed 1845 times
Using standard callipers for hand brake and 911 callipers for foot brake would work on one side- but due to panhard rod mounting- there is no room for the 911 calliper on the other side.
So with options running out, an internet search showed that Wilwood now do a calliper that has a hand brake cable attached to the brake pads. This is an option used by a local Escort prep business. My view was that this was questionable at best. However- if Wilwood are selling them then they must have some credibility. The problem is , and my initial reason for dismissing this idea 12 months ago, is that the mounting of the Porsche pads does not allow extending of the pads backing plate to mount a cable.
After some head scratching and a bit of a Eureka moment – I think I have found a solution.
The Porsche discs are 20mm thick. The new Fiat discs ( Argenta/Strada 256 dia) are 12mm thick. So put a 4mm plate behind the brake pads and extend this to take the cable. Due to the close proximity of the wheel, the amount of metal sticking out past the pad is limited, but there should be enough to fasten a cable to. Also means standard pads can be fitted, without mods.The only issue is that the anti rattle springs will not fit. After more searching, the general opinion is that these are anti squeal springs. As it is a rally car, this may not be an issue, but I have noticed some different design springs that should fit with a small mod if I find they are required.
With all of this sorted, I set about designing the mounting brackets etc. These are currently a prototype, and may be modified before final manufacture.
The mounting consists of an 8mm steel plate ( BDMS bar) that is bolted to the original Fiat calliper mounting point. Originally 10mm plate was used but this only gave a 0.5mm clearance to the disc. On investigating strength of bolts, threads and thread lengths I confirmed that 8mm would be suitable and changed the plate to 8mm. The 2.5mm gap to the disc should be ok.
The calliper is then bolted to this plate. An aluminium spacer was made and the calliper is fastened with cap screws. ( Ignore washers in pictures – the bolts will be machined to correct length) . Threads for mounting are all fine pitch and grade 10.9 blots.
Using an old set of callipers the brakes were assembled and tried. Clearance with the 13” wheel is better than I estimated. Also the callipers fit with 25mm spacers. ( shown in the pics with 30mm adaptors).
So after assembling both sides, I am happy that it will work. The axle was then stripped down again and the final welding carried out. A coat of paint and it will be ready for final cleaning and assembly.
rear brake components-1.jpg
Rear brake parts
rear brake components-1.jpg (114.3 KiB) Viewed 1845 times
rear calliper mounting plate.jpg
Rear caliper mounting plate
rear calliper mounting plate.jpg (82.32 KiB) Viewed 1845 times
rear calliper mounted 1.jpg
Rear calliper mounted ( spare calliper)
rear calliper mounted 1.jpg (88.97 KiB) Viewed 1845 times
rear calliper in wheel.jpg
Showing clearance in wheel
rear calliper in wheel.jpg (127.28 KiB) Viewed 1845 times
calliper- spacer plates.jpg
Showing 4mm spacer plates behind pads. cable will fasten to these two plates and pull them together. Initial test shows quite good grip on disc. It may be that inital application by hydraulic (ie push foot on brake) then apply handbrake (cable) will work well. Under Vehicle use regs - it is the retaining of brake that has to be mechanical not its application.
calliper- spacer plates.jpg (138.93 KiB) Viewed 1845 times
Next step is putting front brakes on. I now have the balance brake assembly, master cylinders and flexible pipes and fittings. I have bought a BMW handbrake lever as this has a simple facility for 2 separate brake cables to be attached, and can easily be modified to accept a master cylinder as well.
The advantage of using the 911 brake callipers back and front is balance. Using Toms great spread sheet on brake sizing, it was easy to see potential problems with using the 911 front brakes with a number of easier options on the back. Taking into account the weight difference of a 911 and the weight distribution front and rear, I think the use of these brakes will be a good starting point for a rally car. I will probably try with same size brake master cylinders to start with. Also when the car is put on the road standard pads will be used for the initial set up before bringing in the additional variation of competition pads.
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Will01
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Re: Historic Forest Stage Rally 124 Spider

Post by Will01 » Tue Jan 07, 2014 6:03 pm

Intetesting read. I have a question about fuel setup. Is it not best to run the filter king pressure regulator up the front of the vehicle as close as possible to the carbs? Due to the length of fuel line you would have a pressure drop? Is this significant or is it accepted practise?
The brake option sounds very interesting, I am also planning on using some Porsche Brembo calipers on my Capri build. I am following with keen interest.
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Wed Jan 08, 2014 8:23 pm

Thanks Will

Over the last few months I did manage to fit the tank and pumps. The Filter king is in the boot with the pumps. ( I think you will have more room in both boot and engine bay with your build. ) There are advantages and dissadvantages in front or rear mounting. I think with my setup- ( Facet pump with twin 44 on 1800 engine) there will be more than adequate flow and pressure.

I have put a manual valve on the outlet of the tank so that if the pumps have to be removed you can stop the flow of fuel. This will be under a drip tray to be fitted under the pumps. In this way it cannot be seen easily- so can also be used as an immobiliser.
tank 1.jpg
Tank fitted in place
tank 1.jpg (106.01 KiB) Viewed 1840 times
tank 2.jpg
Pumps and Filter King
tank 2.jpg (119.81 KiB) Viewed 1840 times
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Tue Feb 10, 2015 7:01 pm

Well it is over 12 months since my last post on this project. I am embarrassed that many other projects have been progressed and completed, and mine seems to have stalled. ( People have even sailed around the world in this time. )

Various things seem to have got in the way, but over the last month I have managed to work again on the car, so hopefully it will progress more quickly.

As with these things you seem to do a lot of work with no progress and then things come together quite quickly. I will update you over the next few days on where I am now.

The first part was to complete the front suspension. I am still unsure about the front tie rods, but assume because it worked on the old Spider, it should work now. I will investigate more when the car is complete and the sump guard is on.

The front brakes are now fitted. It took 2 attempts. We designed a brake mounting plate for the 911 callipers. The hub was fully assembled and fitted, but the front spring was left off. This was so we could test the full suspension travel and make sure nothing fouled. Good job we did. The calliper caught the bottom suspension wishbone on full lock. The original design had the calliper at the quarter to/quarter past position. A quick re calculation and a modified bracket was designed and made. This was tried and works perfectly. ( See pictures below). This problem would not affect the Abarth cars with the different lower wishbone.

ns front brake 1.jpg
N/s front brake
ns front brake 1.jpg (85.91 KiB) Viewed 1791 times
The flexible pipes were fitted. These seem easy to make, but the outer s/s braid certainly does not do your fingers any good. I will let you know how good they are when the system is pressurised.

All of the flexible pipes on the car will be the same length and fittings, reducing the spares requirement.

The hubs are Fiat 125 with larger bearings. The system was tried with the wheel on and everything fits ( 30mm hub adaptors) . As yet have not fitted shocks (Koni Sport) as cannot compress the suspension enough (No engine) Working on a solution to this other than jamming a block of wood to the garage roof!
Attachments
os front brake 1.jpg
o/s front brake
os front brake 1.jpg (71.58 KiB) Viewed 1791 times
os front brake 5.jpg
o/s calliper mounting.
os front brake 5.jpg (101.88 KiB) Viewed 1791 times
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Thu Feb 12, 2015 9:03 pm

The axle was built on the bench ( well on an engine stand actually). The original idea was to use Porsche 911 rear callipers and a Willwood spot calliper for the mechanical hand brake. After much trial and error, this did not work. The Rally Escort guys use a cable that pulls the 2 pads together on the hydraulic calliper. After much head scratching, looking at some Escort installations, and looking at the rules for MOT, I have decided that this will work. The Mot Law ( in simple terms) says that the parking brake must be retained mechanically. So this is not an emergency brake, it is a parking brake. This is why modern cars can have an “electrically” operated brake. While the brake is applied electrically, when the electric power is removed, the brake is mechanically held in place.
This seems to work with the cable operated disc hand brake. Having a cable pulling the 2 disc pads together on its own does not normally give a satisfactory “hand Brake” due to poor mechanical advantage. However, if the pads are pushed onto the disc hydraulically, and then retained by the cable, the result seems to be better.
This is the theory – I will let you know how it works.

The Escort guys weld a lug on each brake pad to locate the cable. My system has a neater solution.

The rear discs are 12.0 thickness. The standard rear Porsche disc is 20mm. This give a difference in thickness of 8.0 mm. On my system I have made a 4mm spacer plate to fit between the calliper piston and the brake pad. ( looks like the brake pad backing plate). The design of the spacer extend out from the back of the pad to allow the brake cable to attach. This means the standard pads can be fitted each time, and the brake cable can be attached to the spacers.
Only down side so far is that the anti rattle springs of the Porsche callipers do not fit. I am trying to source alternatives, but I am not convinced they are really needed for a competition car. Any views?
axle 1.jpg
Axle and parts
axle 1.jpg (92.86 KiB) Viewed 1720 times
axle 2.jpg
Axle from rear
axle 2.jpg (84.18 KiB) Viewed 1720 times
The axle was fully assembled of the car. The LSD was installed so the axle could be easily fitted to the car as a complete unit. The rose jointed rods and panhard rod we trial fitted. You will see from the pictures the complete axle and rods etc. The rear antiroll bar fitting to the axle has yet to be finalised. The mounting points are on the axle and body, but I need to design links between axle and bar.
The panhard rod fitting at the axle end has been modified. The Escort guys use a rose joint bolted on 1 side only. Time will tell if this is ok. Helps with ease of fitting.
You will notice rubber “buffers” mounted on their axle. This was a mod on my previous Spider carried out by the previous owner. They are actually Aeon Rubber suspension rubbers. The normal bump stops are removed, and these rubbers take their place. They are modified to alter their effective spring rate. They have the advantage that you can reduce the spring rate on the rear slightly, but the rubbers do a better job of progressive compression when near the limit. Worked a treat on the old car so will see how they go. Fastening with jubilee clips worked without problems on the original car so I think they will be ok on this.
The axle was then ready to fit. The flexible brake hoses will be fixed after the initial system filling with fluid. The 4 way connector on the back axle is to connect the axle to body pipe, and also a bleed valve. ( you can get bleed nipples to fit these connectors. ). This means that if you have to work on the forward part of the rear brake system ( ie the hydraulic hand brake master cylinder,) then you can bleed the pipe at the axle, not at each calliper.
After what seemed to be a very long time working on the axle, it went onto the car in an easy 1.5 hours- working on my own.
The rose joints will not be covered. There are 2 trains of thoughts on this. Protect the joints with rubber boots. – Advantage, keeps most of the dirt out. Disadvantage- keeps all of the water in. As forest rallying takes place in usually wet and damp conditions this means after every rally you have to disassemble, clean and refit. Having no cover fitted means the potential of dirt and moisture. However, I am using water repellent grease (designed apparently for oil ring installations). Liberal application of this and checking at service is easy- so we will see how it goes.
So we are now at a point where wheels could be fitted if required.
axle3.jpg
panhard rod mount and general strengthening
axle3.jpg (87.8 KiB) Viewed 1720 times



Next job – connecting the brakes.
Attachments
axle4.jpg
rear of caliper showing mounting bracket and you can see the spacer plates between pad and piston.
axle4.jpg (85.63 KiB) Viewed 1720 times
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Fri Feb 20, 2015 7:18 pm

Next job – connecting the brakes.


My vision was to have a brake balance system, but still retain the servo. ( This is a RH Drive car).
My previous Spider and the ST had this system but used 2 remote servos in the brake system. On the original Spider these were mounted in the passenger footwell and on the rear seat area. The main problem with this system was bleeding the brakes. A complete nightmare.
My idea was to keep the original servo, and then mount the brake balance assemble onto the servo.
What seemed a good idea, ended up being too difficult, and not really practical. Firstly to locate the balance system onto the servo proved more difficult than anticipated. The design of the interface plate proved challenging. After 2 failed attempts, it was decided to run the system without a servo .( as per works cars). Another issue was the support of the balance assembly. This was a large weight to be suspended off 2 x 8mm bolts that are fastened to the pressed steel plate of the servo case. Supporting the balance assembly , even with flexible mountings, caused other concerns. ( Exactly how much flexing do you get of the inner wing/chassis rail on a rally car? )
So back to the drawing board, and the decision was made to fasten the brake balance unit to the bulk head. This proved quite easy, using the servo mounting plate as an interface. The only mod was to make the balance lever fit onto the brake pedal. Modification of an old master cylinder rod made fitting easy. Getting the correct length took a few trial fittings, but overall it was a relatively easy fit using a “universal” Balance brake unit.
master 1.jpg
universal balance system with extended rod for fitting to brake pedal
master 1.jpg (109.15 KiB) Viewed 1676 times
A disadvantage of no servo meant that the was a hole around the brake operating rod and the bulkhead. Some form of grommet is required. ( required by MSA rules) . After a search on the net, the solution appeared to be a steering rack gaiter for an early mini. Cut the end off and it fits perfectly on the rod and in the balance assembly. ( and cheap!) See picture.

Having looked at the data provide by Tom, I decided on 0.75” brake master cylinders on front and rear. I have 38mm rear pistons and 48 mm front. Porsche use 19mm diameter master cylinders as standard on the early 911’s . As the 911 is rear engine, I assume there is naturally more braking on the rear than a front engine car. This should be ideal for a rally car as a starting point. I also notice that a “first mod” on early 911’s is to increase the brake master cylinder size to 23mm. This will be my option if the current system is not to my liking.
So next job is to connect the brakes. This is not quite as simple as it sounds. To connect the brakes I need to install the hand brake lever. This will only be positioned when the seat is installed. To install the seat I need to fit mountings ( not easy due to the transverse bar in the floor.). To install the seat I need the steering wheel and column in place- and the correct steering wheel, to get the position.
So a few jobs to do before the brakes are connected.
master 2.jpg
steering rack boot before mods
master 2.jpg (104.98 KiB) Viewed 1676 times
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Will01
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Re: Historic Forest Stage Rally 124 Spider

Post by Will01 » Sat Feb 21, 2015 9:07 pm

I like your brake bias box, i too and going down this route although i will be making from scratch to fit my Capri.
You mention the nightmare of the servo installation, but if you are looking at trying to make the pedal easier to modulate and easier to push because of no assistance, have you you looked at changing the point on the brake pedal where the old servo rod connects?
On my Capri, i just worked out the standard lever ratio i have using the standard pivot hole, pedal length and where the brake rod attaches. Once i knew this i did a little research online to figure out what a non servo assisted pedal should have for ratio assuming load i would be able to put on the pedal. Check out the excel sheet i put together to work it through. viewtopic.php?f=5&t=2992&start=120
The other reason i did this was because my wife will also be using the car to drive on track and i need to be able to modify the brakes in order to allow her to make the most of them as intend not fitting any servo for assistance.

Std Ratio was circa 4:1, for non servo brake systems you are looking at using 5:1 or 6:1 in order to make sure you don't have a solid pedal and are able to maximise the brakes.

Might help?
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Sun Feb 22, 2015 7:51 pm

Hi Will

Thanks for the input. I never thought about the pedal ratio. Certainly it seems a very effective alternative that I will consider if I find problems. Certainly easier than adding twin remote servos.

I have spare brake assemblies so I can work on the ratio on the Fiat assembly.

Nigel.
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Fri Feb 27, 2015 10:05 pm

While waiting for parts for the seats, steering wheel etc, I decided to look at the engine. I have parts to start the build of an 1800 engine (86mm bore). As yet I don’t have the cash to ship it to Guy (my obvious first choice.) So I have to either bite the bullet now and start the build, or wait and see if I can get the money together.

Then I had an idea to keep the project ticking along. There are still plenty of things to do on the car, some of which can only be done with the engine in, so delaying the build even more. So why not fit a temporary engine to get the car moving and allow completion of things like radiator, oil cooler etc. Swapping an engine is not a massive job.
So what to fit? I have a number of possibilities sitting in the garage. 1608, 1800 US spec or 2 litre. The one that sprung to mind was one of the 1608 engines- the one from my old rally Spider. This has been stored in a dry garage, with clean oil in the sump, oil in the bores and turned over with a spanner on a regular basis. As this has been a long time (15 years) I need to give it a once over and change a few things. Also it is the only engine that I know the history of.
Removing the sump revealed a clean bottom end. Removing a couple of bearings showed perfect bearings and crank. As the engine is only intended to get the car moving and on the road- not for competition, then I think it should be ok. I am fitting new seals and timing belt and the new carbs are on the way. ( fitted the old 40 IDFs to my ST and then sold it- so have bought new 44 IDF as the new 1800 engine will need them).
The engine was built by Langprop Engineering in the 70’s and had little use . It has a ported head(?), 70/30/30/70 cams, matched manifolds and a 4:2:1 manifold ( that fits on a RH drive car). Remote oil filter and cooler and it also has Abarth lightened cam pulleys.( unfortunately not adjustable. ) It used to go extremely well and was allegedly dyno’d at 135 BHP. It certainly held its own with 2l litre Pinto rally Escorts in its day.

Talking of Abarth- this engine is also fitted with an Abarth big wing sump. Now I understand that there is some differing views on these items. Firstly- it is Aluminium not painted steel. ( The ABARTH name is cast into it.) It has one baffle plate but no trap doors in the wings, so would have little advantage on a circuit for example. It does give much better ground clearance though. I have attached a picture. Mourenhout claims he has only ever seen one other – so I suppose it is quite rare, even if not very effective!.
The sump will go back on this engine for now, but I don’t think it fits the 1800 block so will be redundant in the final spec car.
Attachments
sump.jpg
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sump 3.jpg
sump 3.jpg (63.42 KiB) Viewed 1601 times
sump2.jpg
sump2.jpg (62.81 KiB) Viewed 1601 times
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TomLouwrier
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Re: Historic Forest Stage Rally 124 Spider

Post by TomLouwrier » Sat Mar 07, 2015 5:05 pm

hi Nigel,

A bit slow to react, but that's an interesting looking rear ARB. Where did you get it from? An AS torque-tube rear axle of from another car entirely?

regards
Tom
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Tue Mar 17, 2015 6:51 am

Hi Tom

It was fitted when I bought the original Rally Spider in 82. I think it is original 124 Spider- so yes from a torque tube model. The original drop links looked like a production item. I notice that there are thicker ones available in the USA, which is something I may consider later if required.



Nigel.
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Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Fri Feb 12, 2016 5:18 pm

Hi All
Well last year was a bit of a disaster regarding the rally car project. Life just seems to get in the way. Anyway, as I am getting older- I said that if the car was not driveable by March this year I would buy a prepared car to go rallying in. That convinced my wife that I should spend more time on the car. (Not really her fault that I have not been working on it but I have to blame somebody. Certainly over the Christmas holiday, I managed some work and it is now starting to progress, although many issues keep cropping up.

So last time I was looking at finishing the brakes, and had to find the location for the hand brake. So I bought a steering wheel with quick release mechanism, fitted that, and then had to locate the seat. This was not as easy as it seems- the cross floor stiffening mean you can’t use standard off the shelf mountings. IU ended up making my own out of the correct aluminium angle and flat. It still gives the adjustment, and complies with the MSA regs. The other problem is the width of the seat (on the headrest). When the doors are fitted, the “wings” on the seat will catch the door, so a small “dent” will have to be incorporated.

At the same time I was fitting the “slave” engine and box, which gave me a better feel for the correct positioning.
So with all of this work, calculation, trial and error- I could now fit the handbrake. Yes, the best position was in the original position!
So after this I was able to fit the handbrake and devise a system for the hydraulic and cable operation. This also caused some head scratching. My previous spider had only a hydraulic hand brake. Now it is required to have cables as well, not only for the MOT but at scrutineering for the rallies. The local Escort pre shop uses cables that pull the pads together on the rear discs, and this seems to be the way forward. Regarding the MOT- it actually states that the parking brake is retained mechanically. It does not have to be applied mechanically. It would appear that if you apply the pads with the hydraulics, the cables will retain the pressure (Certainly enough for the MOT test.) Anyway we will see what happens.

So I mounted the brake master cylinder in line, and constructed a cable system that also attaches to the modified handbrake. The cable on the handbrake lever is a single cable which then goes onto a yoke – where it splits into 2 and is adjustable. It all sits neatly on the floor and actually pulls the pads onto the disc quite well without any hydraulics. I think on the rally the cable may need adjustment- so I can get the full benefit of the hydraulic effort- but again something to test when it is on its wheel and running.

You can see on the pictures the cable and master cylinder are operated from the same arm. The cable runs in a slot in the arm and is held in place by a soldered ferrule (Silver solder). The cable then runs under the master cylinder mounting bracket, which is spaced off the transmission tunnel. The outer sheath of the cable is fastened to the underside of this master cylinder mounting, and then passes through the box section to the rear seat area, where is fastens to the yoke which connects the two individual cables going to each calliper.
There is a hole drilled into the handbrake handle which allows a pin to be inserted when the button is pressed in. This retains the button “in”- so the handbrake is now fly off. ( only to be used on stages)
The brake balance system is now complete. You will see in the picture that the pipe from each cylinder goes to w tee piece. (1 each front and back system). The Tee piece is fitted with a bleed valve. This is to aid bleeding the brakes. The problem with a balance system is bleeding each cylinder. If you only bleed one system, the peddle may not go down to the floor ( depending on the balance set up) To get full stroke you need both cylinders to empty. So – for example- if you want to bleed the front callipers, connect a pipe to the T piece of the rear master cylinder, open the valve and bleed that cylinder at the same time you bleed the front callipers. You won’t have to jack the car up and remove the rear wheels. Obviously in the garage, then using a vacuum system to bleed the brakes will make this redundant, but in a service area in a rally- this may help.
I will take some more pictures of the other work and post them soon.
handbrake 1.jpg
Handbrake Overview
handbrake 1.jpg (63.54 KiB) Viewed 887 times
handbrake 2.jpg
Handbrake showing operating arm
handbrake 2.jpg (66.29 KiB) Viewed 887 times
brake balance 1.jpg
Brake Balance System showing "bleed valves"
brake balance 1.jpg (76.88 KiB) Viewed 887 times
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Guy Croft
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Re: Historic Forest Stage Rally 124 Spider

Post by Guy Croft » Fri Feb 12, 2016 8:46 pm

that sump - without trapdoors, is completely useless..

G
Guy Croft, owner

Rallyroller
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Re: Historic Forest Stage Rally 124 Spider

Post by Rallyroller » Fri Feb 12, 2016 9:55 pm

Hi Guy

I know! It just shows how technology and understanding has progressed. A works tuner developed an aluminium cast sump that did not give any advantage to the health of the engine. ( perhaps only ground clearance)

Nigel.
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