Engine Autopsy
German-built American Ford engine, popular in Sweden and France
We delve within Saab’s V4.
Ford’s European operation found itself with two V4 engines and two related V6 engines in the Sixties. One was this example – the Cologne family – and the other was the Essex, created slightly later in the UK. The Cologne was designed in Detroit for the sub-compact American model that morphed into Germany’s Taunus 12M, first appearing in 1962 in 1.2- and 1.5-litre form.
After several years of success in the Taunus and Transit, Ford bought some Saab 96s to fit with the V4 and convinced those at Trollhättan to take it on as a replacement for the twostroke triple. From the 1967 model year it powered the Saab 95, 96 and Sonnett, and it also appeared in the mid-engined Matra 530. The Saab version lasted in 1.5- and 1.7-litre form until the end of 96 production in 1980.
[A] TIMING COVER The engine's large front cover not only conceals the three timing gears (opposite page) but also forms part of the body of the water pump, seen here on the right-hand side. The pulley (above) pokes through the lip-type oil seal next to the pump, engaging with the nose of the balance shaft (opposite page, bottom). The circular item in the centre of the cover is the rear of the fan bearing. [B] HEADS AND ROCKER COVERS The combustion chambers are in the cylinderheads in the Cologne V4, rather than in the tops of the pistons as they are in the Essex. Each has a separate inlet tract, but the exhaust paths are siamesed to one outlet for each head (shown here pointing towards the rocker covers). Tuners altered this for high-performance heads.
[C] INLET MANIFOLD The inlet manifold is shown with the back (or flywheel end) to the left, like the rest of the engine. The cut-out on the left allows the distributor to slot into the block, while at the right end we see the coolant feed pipe to the heater and the large aperture where the thermostat housing (above) fits on. In the centre is the mounting for the single-choke Fomoco (Ford Motor Company) carburettor. Next to the thermostat housing is the camshaft thrust plate.
[D] ENGINE BLOCK The distributor fits into the large hole at the rear of the sturdy engine block’s upper surface. It’s driven by a scroll gear on the camshaft, which sits high up in the centre of the block and operates followers that slide snugly into the eight staggered holes above it. This is a ‘closed-deck’ block. Ford revised the design from an earlier open-deck approach that looked more like a wetliner engine with the heads removed. The closed-deck version is less prone to head gasket failure. [E] OIL PUMP AND SUMP The pump sits below the centreline of the crankshaft, dipping its pick-up into the deeper section at the front of the sump and taking its drive from a slim pencil-like shaft that fits into the base of the distributor drive.
[F] TIMING GEARS The small steel crankshaft gear at the bottom drives the large camshaft gear above it and the small balance shaft gear to its left. The latter two are fibre, which makes for quiet running but a shorter lifespan than steel or aluminium replacements.
[G] VALVES AND SPRINGS In typical workmanlike Ford fashion, single coil springs cope fine with a relatively lowrevving design. The larger inlet valves are outboard of the smaller pairs of exhaust valves.
[H] PISTONS The Cologne was seriously oversquare in 1.5-litre form, with a bore more than 50% larger than the stroke. A shorter stroke reduces the difference in acceleration between ascending and descending pistons, but the large bore increases the size and mass of the pistons, so the second-order vibration you get in all in-line four and V4 designs still needs fixing – see ‘Balance Shaft’. [I] ROCKER SHAFT AND PUSHRODS Just two fasteners secure each of the short, hollow rocker shafts. The ball on the ‘inside’ of each rocker meets the cup of a pushrod and can be screwed up and down to adjust the valve clearance.
[J] CRANKSHAFT The crank is sturdy and difficult to break, thanks to three wide main bearings and its short stroke. Note the drilling in the counterweight: in an engine that struggles to be smooth anyway, getting the crank balanced properly is a good start.
[K] BEARING CAPS Three main caps bolt the crank securely to the underside of the block. The rearmost one is considerably sturdier to support the extra load created by the flywheel and houses a lip-type rear oil seal. [L] CAMSHAFT AND FOLLOWERS These are the followers that slide into the eight holes visible across the top of the engine block. At the rear of the camshaft we see the scroll that drives the distributor and oil pump.
[M] BALANCE SHAFT This shaft fits into the block beneath the offside bank of cylinders (lower, as we see it) and rotates at crankshaft speed. It has an eccentric weight at its rear end to counteract second-order vibrations. It’s a weak point: the bearings can wear, allowing the shaft to chatter and damaging the gear’s fibre teeth – which can eventually fail. If the engine feels rough and runs without the fan pulley turning: there’s your problem. n