The Uno Turbo engine conversion

How it was done - March/April 1999 by Dean Donaldson - X1/9 owners club

So the Uno Turbo engine is actually a X1/9 1500 engine block with a smaller bore - anyway but with lots more to it. Basically it drops straight in without to much faffing, but patience is required, but if you're going to go to the trouble of an unleaded conversion, this is one way of doing it...

Once we cut through the sludge we were able to actually seeing what we were dealing with. Having a spare bell housing from an x1/9 really helps.

As you can see from the photo, the Uno and x1/9 gearboxes are quite similar, except the x1/9 bell housing that has gear shifter prepared for rear mounted engine (1) as opposed to Uno's (2)

Using the X1/9 gearbox casing we replaces X1/9 internals with Mk1 Uno for higher 1st and lower final drive ratios. Also use x1/9 reverse idler. Use x1/9 race for clearance on the main shaft pinion, and mount the RPM sensor as per Uno's (3) and align it to the flywheel. Thought now would be also a good time to replace the clutch too. The x1/9 assembly mates onto Uno flywheel.

The sump from the x1/9 had to be used because of the camber on it, but need to make an oil return pipe to fix on it... oh and its aluminum... have fun!!! File off all the tabs too for clearance.

You'll never get that engine in with the oil filter on... come to think of it we'll never get that oil filter in either!!! Better try one from a Lancia Y10 turbo... You'll need to use x1/9 cam housing for mounting bracket with Uno cam cover, Use Uno camshaft and all Uno internals though, which fit no problem...

Couple of days before engine was to be refitted, it was time to attack the engine bay itself... Rust proofed and welded the patches on the suspension struts, she was etched-primed and sprayed... not a run in sight!

Well with a sparkling engine and engine bay, it was easier to lower the exxy onto the engine than drop the engine in... did it fit... well with the oil filter removed it did!!! After fixing the lower engine mount back on from the x1/9, careful maneuvering of jacks and hoists, we eventually lowered her down.

Once firmly lowered to the floor, we began fixing the side and top braces... both from the x1/9.

Oh yes, with a slight kink to the top brace to pull it away from the exhaust chamber. (1). Had heard a lot of people had kept the distributor at end of engine block as in Uno (5), but we found more space was gained if we left it on side as the x1/9 is (2). Meant we had to take a blanking plate to the end of the cylinder head and fit the water thermostat (5) from the x1/9 and you can retain most of the x1/9 water pipes (as well as a couple of new and replacement ones!) Welding the mechanical advance in the x1/9 distributor means you have set it to cope with the electronic ignition system. Also will need to remark your dipstick (3) to allow for the extra depth of the x1/9 sump. Bring the pipes from the x1/9 radiator and connect to breather on engine block (4). And remember to use the oil pressure switch (4) for safety cut off of fuel injection... Underneath you will need to use the Uno's intermediate driveshaft to alternator bracket mount and two X1/9 short drive shafts, so make sure you have a spare one handy! Use a CV joint as a spacer and get some high tensile strength coupling bolts.

Modifying the bracket for the X1/9 coolant expansion tank by cutting away a couple of inches (1), and time to fit the fuel system... You will need to marry the x1/9 and Uno pipes with a couple of downsizing connectors (2), as well as replace both the inline fuel filter attached to the fuel pump (7) and canister fuel filter. Ended up having to get a new ignition relay switch too (2) as these are expensive and the first things to be taken at a scrapyard! The Intercooler which will be located left side, needs to have the bottom pipe that connects to the turbo (3) chopped and welded in order to lay over the gearbox at the right angle, and you'll need to fabricate a a mounting bracket too. Modify the air flow meter bracket (4) to allow fitting sideways, and mount to top strut brace on the cam housing and then invest in a K+N cone filter (5). It saves lots of room, increases air flow and sounds lovely!!! Fit a new T-piece in between turbo, expansion tank and water thermostat housing (6).

Once you get to the electric's, you need to work out which loom to keep and which to ditch! Invest in some serious leads and plugs would be my advice such as Splitfire's twin core! At first, the electric's it look like a snakes wedding, but we managed to disregard a lot of the Uno loom used for their digital dash boards, and stick with the bare minimum. We found the best place to mount the ECU system was actually in the sparewheel well behind the right seat, and on the centre pillar. It was a bit of a squeeze but its out of the way and kept dry inside the car.

Blank off one of the pipes from the exhaust chamber (1) and get a nice new lengthy piece of flexible aluminum pipe (2) to help cool the alternator, which ironically enough, is nicely mounted near the turbo and exhaust! Use the downpipe from the Uno exhaust system, the rest you'll have to make up as you go along!!! We left out all the internal air ducts from within the engine bay... decided the more free flowing the air could be, the less chance of over heating, and she's crammed enough as it is! And it seems to work...

Attach the fuel system as shown in (3) and mount the Uno's ignition coil and power module in position (4). The oil cooler will need to be mounted sideways, with the help of a few fabricated brackets, and altered pipes (5). However, mount no lower then sump or spare wheel bulge in the floorplan. If you have my luck, we went through 3 oil coolers trying to find one that hadn't been split on other Uno's. They are mounted at the front on Uno's and prone to stone chip, and mounting vertically means they just spray oil!!! Route ducting from Fuel injector cooling fan through to Injector rail mounted (7) with a bit of modification. Time to refit the engine bonnet now (6).

And the finished result! All that remained was to have a handmade stainless steel exhaust made with out pipes at both sides of the car. That was done by a local exhaust maker as a one off, because could I find a manufacturer to do it for me? hahahaha...

So what's she like, I hear you cry... well after 6 weeks of being off the road and over a £1000 spent under the bonnet, we reckon we are definitely getting over the 105 horsees standard, after all there's splitfire plugs, ported head and a freeflow exhaust. Not much beats her off the lights, and she cruises quite happily at 100 mph. Its the dump valve and K+N that just add to the whine of the turbo, that makes you wonder why Fiat hadn't done this as standard years ago....

All that remains now is the rest of the car... but that's another story!

New and replaced parts on my engine overhall:

Modifications X1/9 Uno Turbo ie Conversion

Advantages

Power & Torque: Increase over standard 1500 from 85 to 105 bhp & 87 to 108 lb.ft/rpm for Mk1 1300, and to 116 bhp & 119 lb.ft/rpm for Mk2 1400. Post-1988 engines are unleaded.

Weight: Similar to standard unit, so minimal change to handling unlike heavier twin cam unit.

Mounting: No structural modifications are required unlike for twin cam unit. No need to cut into bulk head or boot space, as all extra components can fit in engine bay. Can utilise existing water cooling and air ducts.

Gearbox: Use X1/9 Gearbox casing but replace X1/9 internals with Mk1 Uno for higher 1st and lower final drive ratios. Use X1/9 reverse idler. On main shaft pinion side bearing, use X1/9 race for clearance.

Bellhousing: Fabricate and weld adjustable mounting point for RPM sensor to align with flywheel.

Lower engine mount: Required as X1/9 gearbox and differential housing is retained.

Sump: Retain from X1/9 due to previous slight incline. File of all tabs for clearance. Mount and fit a Turbo oil return pipe. Use X1/9 oil pump pickup and dipstick for extra depth.

Driveshafts: Use Uno intermediate shaft to alternator bracket mount and two X1/9 short shafts (existing and new) plus CV joint as spacer. Increase tensile strength of coupling bolts.

Side engine mount: Required from X1/9 as not fitted to Uno but mating holes present.

Cam Housing: Use X1/9 cam housing for mounting bracket with Uno cam cover. Use Uno camshaft and all Uno internals. Fabricate blanking plate where distributor was.

Top engine mount: Utilise X1/9 top brace, and modify the injector fuel supply rail pipe union for clearance.

Intercooler: Fabricate mounting bracket on passenger side to hang vertically and position for side air duct. Cut or remove duct grills for increased air flow. Cut and weld pipe from turbo to intercooler.

Oil Cooler: Fabricate mounting bracket and position no lower than sump or spare wheel bulge in floorpan. Suggested mounting vertically on drivers side air duct.

Distributor: Modify X1/9 distributor by welding mechanical advance and and mount on engine block.

Oil Filter: Either fit a remote oil filter or retain existing Uno oil cooler coupling and use smaller oil filter (Lancia Y10 Turbo) with pressure release valve. (3" length max. for clearance in engine bay.)

Coolant Expansion Tank: Retain X1/9 tank but modify bracket for clearance.

Water Thermostat housing: Use X1/9 thermostat housing and utilising existing X1/9 water pipes. Mount water pressure sensor.

Water Pipes: Fit new t-piece in between turbo, expansion tank and water thermostat housing.

Air Flow Meter: Fabricate mounting brackets and mount to top strut brace on cam housing.

Air Filter: Replace with K&N or similar to allow for extra space in engine bay and increased air flow.

Exhaust: Use Uno down pipe with fabricated additional section to mate to suitable free flowing silencer.

Fuel injection: Use x1/9 sending unit and upsatge bore to fit the Uno fuel pump.

Fuel Injector Cooling Fan: Fabricate mounting and route ducting to side air duct.

Fuel Pump: Replace with suitable electric version with inline filter. Use oil pressure switch for safety cut off from Uno.

Electronic Control Units and Miscellaneous Electrics: Mounting required for both injection and ignition ECU's. Suggested mounting in spare wheel chamber behind drivers seat. Also use Uno ignition coil and power module and mount near oil cooler on drivers side.

Wiring: Use standard Bosch LE2-Jetronic injection and Marelli Microplex ignition system looms. Sensor feed required from starter motor. Refer to Haynes workshop manual number 923 for wiring diagram.

Braking: Use Uno front calipers and fit race discs and pads all round, such as Tar-Ox. Possible braided hoses and (Servo from Fiat 126 or Hillman Imp?)

Required Modifications (Mk2 1400 only):

Flywheel: Required from Mk1 Uno with X1/9 clutch.

Turbo and Manifold: Required from Mk1 Uno as insufficient clearance for larger Mk2 version.