Lancia Fulvia
Narrow-angle V4 packed with Lancia’s unique brand of cleverness
Vincenzo Lancia created his first narrow V4 for the innovative Lambda in 1922. Like all his company’s subsequent variations on this idea, it used one cylinder head to cover two banks of cylinders. This allowed Lancia to create a useful cubic capacity in
[A] CAM COVER The large cam cover with its deep spark plugs wells is one of several impressive alloy castings. The ribbed sump pan (bottom right) is also alloy. The hole in the baffle shows the position of the oil pick-up.
[B] CYLINDER HEAD Despite the V4 layout, the head is a crossflow design. As we see it here, the inlet valve of each of the hemispherical combustion chambers is at the top and the exhaust valve is at the bottom. This creates very uneven port lengths, which has the effect of flattening the torque curve and allowing the use of unusually large carburettor chokes. The distributor fits into the rear left (top left, as we see it).
[C] BLOCK AND CRANKCASE We can see the slight angle between the cylinder 'banks' in the cast iron block. Specialist equipment is needed for a rebore or the pistons on one side will rise higher than the other. We’re looking at the top of the alloy crankcase, which mates with the bottom of the block.
[D] WATER PUMP This mounts on the front face of the block and is driven by the timing chain, via the small pulley on the opposite page. Seals in the impeller shaft stop coolant entering the engine and oil entering the cooling system. Seal failure can lead to a potentially catastrophic mixture of the two.
[E] COVERS The timing cover fixes to the front of the crankcase, with a liptype oil seal for the crankshaft's nose. Its shape shows the angle at which the engine sits in the car: the lower surface is horizontal and mates with the sump. The rear cover is shown with the outer face towards us, which would normally be adjacent to the flywheel.
[F] OTHER BITS The slender oil filler casting contains a flame trap. It fastens to the two studs we can see at the rear of the head. Beneath that is the oil pickup and strainer that rests in the sump. Finally we have the crankshaft pulley. It's a plain steel item: the well-balanced design requires no additional damping. a very compact engine. Making it work, though, called for some highly original engineering.
Ettore Zaccone Mina took the performance potential of the layout to a new level in 1963, with the Fulvia engine we see here. He made it oversquare and designed a unique crossflow cylinderhead with separate camshafts for inlet and exhaust valves. It started at 1091cc, but grew eventually to 1584cc for the HF Coupé and Sport Zagato. This one is a 1298cc unit from the Series 2 Coupé, built shortly after Lancia surrendered control to Fiat in 1969.
[G] TIMING ASSEMBLY The long duplex chain is turned by the sprocket on the nose of the crank. It runs up inside the chambers in the front of the block and head, past the water pump sprocket and tensioner, round the two camshaft sprockets and back down again.
[H] TENSIONER A weak spring pushes the guide against the chain, but oil pressure does most of the work. Resistance increases to stop the chain dancing around as rpm increases.
[I] PISTONS The amazing angle-topped pistons are also domed to give a high compression ratio. The con-rods are desaxé – or off-axis. This reduces thrust face wear in the bore and ensures the rods are past vertical in the cylinder when the combustion stroke begins.
[J] CRANKSHAFT The sturdy little crank remained much the same for all engines up to 1300cc, but gained extra strength and nitriding for the 1600HF. The big end journals are positioned at odd degree intervals to achieve balance with the small V-angle.
[K] CAMSHAFTS There's one camshaft for the inlet valves and one for the exhaust valves. The inlet camshaft has a scroll on its tail to drive the distributor. The front ends of the shafts locate in bronze bushes. Their other journals run directly between the cylinderhead and the rocker shaft pedestals.
[L] VALVEGEAR The valves, concentric springs and caps are conventional enough, but there is a unique feature about the way they’re actuated. Short pushrods are needed where the rockers have to reach across to the valves in the other ‘bank’ of the head. Each one is guided by cast extensions on the rocker shaft pedestals.
[M] BEARING CAPS The large main bearing caps are all of different widths. The rear one carries the thrust washers.
[N] OIL PUMP AND DRIVE This shaft fits diagonally inside the timing cover, driven by the scroll gear on the nose of the crank. The lower end drives the oil pump (below), which bolts to the lower left of the timing cover. The top end locates in the top-hat casting (above). The hole in it is for the fuel pump plunger, which is pushed in and out by the little cam at the tip of the shaft.
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WORDS Nigel Boothman PHOTO Matt Howell DISASSEMBLY Sam Glover THANKS TO Tim Heath of the Lancia Motor Club (lanciamc.co.uk) for expert advice; Martin Boothman for the loan of the engine.