Fiat 126 Bis

Cool car...


I don't have any first hand knowledge of the watercooled engines, but by the looks of it they are basically a big bore version of the Fiat 500 Giardiniera engine with added waterjackets.

It doesnt have a CV joint at the gearbox end, it is more like a wet (on the inside, with the gearbox oil) U-joint.

It works with hardened steel sliders in the diff, and they are pretty much bulletproof.

If it has a tight spot, it is more than likely at full droop ( when the car is on a floorjack ).

The splines on the other end of the driveshaft can fail, though.

But you'll know right away, because you'll have a box full of neutrals and a ratcheting sound coming from the rear.

To replace a driveshaft, the gearbox has to come out and the diff has to be opened up ( this is all assuming the later watercooled cars are similar to the earlier aircooled ones.

You've got the 98X4 boltpattern ( of all the 126's except for the very early ones ), so all brake components are easy to get and very affordable.
So I'd just replace everything, except for the backingplates ( if they are in good condition )

I'd also lower it a bit and get some good shocks.

They can handle extremely well ( no matter what Ralph Nader says about rear engined cars...) and be a lot of fun...

On faits

I've raced cars with 600 and 500 boxes in them.

Most sloppyness in the shifting comes from the mechanism, or at least more than the boxes themselfs.

( So I usually make my own mechanism, to make the action more direct and tighten it all up )

These boxes can handle lightning fast shifts, but at higher HP levels can get a bit fragile.

For street use they can stand up to a lot of abuse as long as you never shift down into 1st while the car is still moving.

Cool car but the rally version you see in action above is powered by a motorbike engine.
I had the build and several races in my YouTube playlist before they got greedy and tried making us pay to watch ads.

I had one from new in 1988 or 1989. I think they had just come out then as I vaguely remember looking at the (for the UK) previous version with air cooled engine the year before. The video above I think covers nearly everything.

I had been in Poland a year or two earlier and was driven around for many hours in a Polish air cooled one four-up. They took a fair while to warm up in winter and the family squeezed in with coats I guess expecting the car to not be particularly warm. Much like everyone crammed on a bus or tube train at rushhour.

My Bis heated just fine (for UK weather a least).

The Bis felt like a pre-electronics Porsche, (but at lower speeds) everything was tight and the back end was always threatening to kick out. It felt really purposeful and pure. Thinking about it, it felt like a modified car that's just a bit too 'rallycar' for the road, stiff suspension and needed concentration.

Compared to the air-cooled, the Bis had larger wheels with low profile tyres. While a 2cv I had with similar engine size and 2 cylinders could be a relaxed drive, the BiS was furious at any speed.

Coincidentally or not I had two cars crash into my Bis during ownership. No accidents before or since. Having owned it 3 days, my first ever and only brand new car, someone went in to the back of it while waiting at traffic lights. Also at work I returned to the carpark to find someone went into the front end and crushed it in. It was able to drive after both events. But it always felt somehow invisible or perhaps psychologically further away for drivers so they misjudged distance I don't know.

Being a small but well geared car, it drove like anything else around town but on dual carriageways or motorways, while it would do 70mph, that was about it. I was frequently tailgated by trucks on the motorway and couldn't get out of the dangerous situation.

I eventually changed it in for a poverty Spec Panda 750 as I was spending a lot of time on the motorway and it felt dangerous - or rather it couldn't get away from dangerous drivers tailgating. The 750 fire engine (acronynym - Fully integrated Robotized Engine - not .. you know. ) was much better for the motorways though even that was weedy. (looks up specs... 26bhp Bis, 34bhp 750 Panda a 30% increase). While both are primitive NVH-wise, the Panda felt much less buzzy. Some days I practically fell out of the Bis with buzz fatigue.

I believe the Bis's, though made in Poland, weren't sold there. Once the Bis was produced the air cooled 126's were no longer sold in the UK. FSM continued to produce an air-cooled 126 up to 2000 while the Bis ceased production earlier.

It may be that the air cooled 126 was cheaper or was seen as simpler & more reliable in the Polish market.

It is possible to fit a Fire engine in the back of a 126. While I'm all for bigger engines normally, the small wheelbase and extra rear weight could make this deadly. With the Fire engine having I think 170bhp in the Fiat 500 Abarth, 100bhp as a n.a. 1.4 in the Panda - nice for an airfield maybe

Also see this:

www.fiatforum.com/126/453333-126-bis-fire-engine-conversion.html