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16v versions

Picture 1. 16v engine. As the other late model TCs, the engine is tilted forward 20 degrees.

Although the 8-valve head has excellent flow capacity, it was needed to develop a 16-valve head for further power and economy improvements. This was mainly used on sporty Lancia models, but it can be found from newer Fiat models also. The engine is fuel injected and almost all of the engine versions had 150bhp or more. Turbo models had sodium-cooled exhaust valves and bronze valveguides.

The head - apart from the other TCs - has integral camshaft bearings. The other halves of the bearings are located on the head and the others are in small bearing covers. This is quite common structure on newer 16-valve heads, and the camshaft lift is not limited by the size of the bearings, as in the 8v models.

The head can be used with any TC bottom-end. The 16v engines, like the late Lancia engines generally, have eccentric balance shafts that reduce the vibrations of the engine. The shafts rotate at multifold rate compared to crankshafts and make the engine run smoothly at low revolutions. Those have no positive influence on performance, and they are usually removed when building the engine for racing purposes.

If the head is going to be used on a vertically mounted engine, the oil return galleries of the head need modification to maintain the correct oil level in the camshaft boxes. Of course, the pistons must have correct valve cutouts, and the timing belt pulley of the bottom end needs to be changed to 16v item. This is because the 16v engine has different timing belt toothing.

The valve lifters and shims are the same as in all of the Fiat/Lancia 8-valve OHC models. This is a notable benefit for those who have shims in store.

Picture 2. Cross-sectional drawing of Lancia 16v engine.

The head - when preparing for tuning use - works very well with its standard form. Without minor changes, and when equipped with 2l bottom-end, rally-profiled camshafts and 45mm carburetors, 200bhp can be measured from wheels. The compression ratio should be at least 11.5:1 to fully profit from this head with modern pentroof-type combustion chambers. The camshafts and other parts of the head are easily available.

If one wants to have some modifications, the short-side radius of the port turns near the valve pocket can be increased. This prevents turbulence behind of the intake valves. Additionally, every head does not have three-angle valve seats. Since the ports are large, low-end performance is not the best possible. Therefore, the head works best with fuel injection.

Picture 3. Valve seats and combustion chambers. Note the large valve sizes, 34.5mm and 28.5mm.

Picture 4. Top view of the head. Note the camshaft bearings.

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