Fiat 131 Abarth Stradale Overhaul

[RedLexus]

Hi all , some time ago a good friend asked me to give his 131 AR Stradale a bit of an overhaul . The car was in decent enough shape , but after comparing it to my Dad's blue one he reckoned certain aspects of the car needed attention . It felt softer , looser almost , the brakes weren't as sharp , nor the acceleration , it had a few oil leaks , some rattles from the suspension and some other related issues . Typical of any older/classic car that has seen a fair bit of use .

So one fateful day I rolled up my sleeves and set to it . First I gave it a good drive , then put it on the Ramp and spent a while prodding and poking with a tyre-bar , seeing what was worn in the suspension and driveline . Several things came to light immediately .
the ARB droplinks all had some play , as did the outer front lower balljoint on one side .
Also the inner ARB bushings themslves were worn.


The rear was the same , with some movement on the ball joint on both sides.

The exhaust system's mounts were perished , letting it bang on the body .


There was obvious leaks from some of the Dampers


The Gearbox rear mount , the engine mounts and worst of all , the Driveshaft "Do-nut" were all worn , the Donut was actually torn!

[RedLexus]

The biggest problem I've found with this car is the pathetic availability of spares! Even engine mounts , which I had thought to be easily available was an issue .
We failed to get new replacement dampers , so we got them re-conditioned . Luckily (for me) the owner arranged that . Naturally I wasn't happy to refit the old looking items , so a quick spray job was in order . And a fresh coat for the coil springs too .



Then back to the ARB issues while the paint was drying . The supplied ones were gound to be completely wrong .....


so after much faffing around , I ordered some Polyurethane items for a Ford EScort and Capri , and with some small modification they were persuaded to fit . I had to change the hanger brackets from the Fiat to the Ford items . Luckily these were cheaply available , and only needed some slotting of the holes .

[RedLexus]

here's the modded ARB bracket. I would have preferred to use Fiat parts , but now we can have Bushings the next day for only a few euros , versus trawling Retro Fiat stockists for weeks .

[RedLexus]

I forgot to take pictures of the new ARB Drop links... again the only ones available were silly money , so bearing in mind my friend was trying to keep to a budget , I ordered 8 6mm Rose joints from a bearing stockist , a length of threaded bar (High Tensile) , and made my own . Rather than leave the threads exposed , I carefully measured a piece of 1.5mm wall steel, 6mm ID pipe , and slid it over the threads , between the top and bottom Rose joints . Stronger , and looks better too!

[RedLexus]

next on the suspension was the lower balljoints . The front was relatively simple I thought... Once I eventually found bottom arms! The were a 2 week search . When I found some , I bought 6 , in case our own two 131's ever need them .
The ordinary 131 is nearly the same , bar it doesn't have the brackets for the ARB drop links.




The rear , was a wee bit different... The lower balljoint is separate to the suspension arm , it's held in with 2 bolts . However as you can see the half shafts have to be removed to take the joints out .





In case your wondering , once I've everything tightened , checked , double and treble checked , I put a Tip-pex mark on the nut/bolt , so I know it's been done . And also so I can see if it is starting to loosen later on . And I always use Locknuts , unless it's not possible .

[RedLexus]

Balljoints and ARB bushes all done , next on the list was check the LSD . Or in this car's case, fit one ! This was the logical next step as the half-shafts were off . I was curious as to whether the OE Diff was in this car , so a pleasant surprise was had when I cleaned it off....


less pleasant was the amount of "gunk" found on the sump pan of the Diff housing . Any ideas what this forms from?



However , removing the diff was a doddle , with the halfshafts off , the entire side of the axle unbolted , the Diff came out with that , and then simply slid off of its splined shafts .



I transferred the ring gear to the LSD , fitted new bearings , and then re-installed it...and by sheer fluke , the back-lash and free play on the new unit was perfect! No need to move , insert , or remove shims!


heres a quick pic of the pinion gear . You can see the drive shaft the diff slides on to.





Rather chufffed , I sealed everything up , with a new o-ring and gasket compound , then filled it to the mark with Castrol B-373 LSD oil.

[RedLexus]

So , the halfshaftss , which are fully floating , ie they have a CV joint both ends , were carefully checked , and found to be ok , as were their Rubber boots . As a precaution , I swopped them side to side , so if there was any wear on them it would be cancelled out by turning the opposite way now .

Engine mounts next... these were as soggy as sponges! Random oil leaks plus a torquey , tall 16v motor had done them in . The owner supplied what were supposed to be OE ones , however they had a larger diameter , and the stud each end was 12mm , not 10mm like the ones I removed.... I suspect the new ones are a RWD Ford item ? Anyone recognise them?



I made a steel plate to help strenghten the mount , to help prevent the rubber sagging , basically a piece of flat plate folded into a very shallow "U" section . You can see it in the pic , between the rubber and the chassis mount , painted silver . It's the small things that count , I reckon...

[RedLexus]

Next thing to do was the brakes . I stripped all the calipers and pads off , and cleaned everything , no major issues . PAds were in good order , as were all the seals and so on . Some of the slides were a bit sticky , so a polish of all moving parts with fine sandpaper and re-assembly , then bleeding . While working on the fronts though , I noticed that the wheels were located solely by the Wheel studs , not with a central locating spigot . The Brake discs looked to have been machined too , as if the spigot was part of them , or something . Possibly to fit wheels at some stage thatweren't the correct fitment?
So some careful measuring up , and my Lathe/CNC equipped mate machined some natty adapter/spacers , one side locates into the centre of the disc and hub , the other side into the centre bore of the wheel . And they also space out the wheels a wee bit , increasing the track .







No such issues at the reart , the correct Abarth items were fitted.

[robert kenney]

less pleasant was the amount of "gunk" found on the sump pan of the Diff housing . Any ideas what this forms from?



Common deposits from oxidation and heat when the differential oil is long for this world.

[RedLexus]

Now..the bit you have probably been waiting for.....Engine dismantling!
Inlet manifold off..


Exhaust manifold off , and moved back away from studs , and 'Cam box covers removed


Cam boxes removed , because unlike the 8v Engines , the Head studs are under the cam boxes . Makes Cylinder head removal a bit labour intensive . In this picture You can see a socket extension reaching down to a Headstud .


And cylinder head off! You can just make out the valve cut-outs in the pistons . As you can also see , its a very similar block to the 8v.


all the bits!


Now , next thing to thoroughly clean the Head.

[RedLexus]

A good wash with detergent , and steam cleaning , before removing the valves and springs.


I gave all the spring retainers a sharp tap with a plug socket and hammer to help unseat the collets , then laboriously removed all the springs , collets and retainers . All valves have double springs. Tired fingers after this job!



once all the valves etc were out , a good clean and examination of everything . These valves have a very wide seat , nothing fancy at all , the port has a mild porting job , possibly from original? I would have dearly loved to have sent the head to the GC workdhop for proper finishing , 3 angle seats etc , but sadly it wasn't in the budget this time .



I cleaned thevalves , and with the guides in decent shape all bar one , I lapped the valves with grinding paste with the old fashioned "sucker stick" . Times like this I remember why I prefer 8v engines...haha

[RedLexus]

On valve guides , one was actually broken! at the top , where the seal sits on . So my preferred engine machine shop fitted a new one , and as you can see , gave the head a mild skim , to ensure it was properly "true" .
So then new valve stem seals pushed on with a socket..


and re fit the valves and springs , making sure that collets were accounted for!




I used some heavy grade engine oil on the valves , as I couldn't get proper assembly lube locally .

[RedLexus]

a pictorial guide to the OE Abarth valve head sizes.

[ace124]

Great pictures !
Im doing an 8 Valve head at the moment also and the similarities with the Abarth 16V are striking!
Seems your doing twice the work though! heheehe

Keep the pictures coming.

Great post

[RedLexus]

Great pictures !
Im doing an 8 Valve head at the moment also and the similarities with the Abarth 16V are striking!
Seems your doing twice the work though! heheehe

Keep the pictures coming.

Great post

Tell me about it....calluses on my palms from the Valve grinding! All for a good cause though . The Head is very similar indeed to the 8v , apart from the headstuds hiding under the Cam Boxes.