Before making a sump, mounts and an adaptor plate for an engine, it’s worth knowing it actually runs. In the third video of the Zetec RWD playlist, Dave’s Garage UK finds out using parts already lying around the garage: a starter motor, an old Ford ignition module, a coil pack and a pair of DCOE carburettors on a Zetec inlet manifold. None of it is meant to stay. It’s a quick, cheap test of the ST170 before real money goes into the conversion.
Video: Dave's Garage on YouTube · watch “Zetec ST170 engine start up on DCOE carbs and ESC module” on YouTube
What happens in Episode 3
Assessing the engine (0:00). The ignition module comes, Dave believes, from a Mk4 Orion or Escort, one of the last carburettor Fords. It works from a vacuum sensor and uses the same connectors as the Zetec for the crank sensor and coil pack, so it should at least get the engine running. Filling it with oil revealed holes in the old sump, hence the odd angle on the stand. The dual-mass flywheel has been swapped for one from a 1.8, a set-up Dave already runs on another car.
A temporary starter (1:31). A starter is held against the block and the bolts measured at about 35 to 36mm; the scrap boxes supply some close enough. The battery leads come from an old jump-start pack, with one damaged end cut back. The starter position is only for the test, as the gearbox will carry the starter in the car. The engine turns over nicely.
Ignition and a spark test (5:13). Dave admits the module’s ignition map won’t suit this engine perfectly, but it only needs to get it running. He warns that later Fords catch you out by using black for live and brown for neutral. The engine’s own coil pack is fitted loosely and earths through its mounting. The centre pin is live and the module switches the earths on the outer pins, firing cylinders in pairs as a “wasted spark”, one of each pair sparking on the exhaust stroke. Other sensors aren’t needed. With a plug pulled and held against metal, there’s a spark.
Fuel (8:37). His usual first try is a little petrol poured down the trumpets: with spark, compression and fuel, he argues, an engine will run, and he reckons TV non-starts are usually staged with the plug leads in the wrong order. He won’t use this sump in the car either. Ready-made ones are £400 or more, and he plans to make his own from sheet steel for about £20, and his own water rail too. It fires briefly, so for a steadier supply he rigs an old tank from a lawnmower or petrol compressor.
It runs (14:58). After a few attempts the Zetec runs on the carbs, kept short for the neighbours’ sake.
Wrapping up (17:22). There are two versions of this module. The red one is easier to find, but Dave believes this one has a slightly better internal map for the Zetec; how it would cope with everyday driving is another matter. He points out oil spatter from a spark plug hole, and says he believes banger racers use a similar set-up with a single carb.
Parts, tools and materials mentioned
- ST170 Zetec on an engine stand, with a flywheel from a 1.8 instead of the dual-mass one
- Ford ESC ignition module from a late carburettor car, plus the engine’s own coil pack
- Twin DCOE carburettors on a Zetec inlet manifold
- A spare starter motor, scrap bolts and old jump-start leads
- An old small-engine fuel tank for the fuel supply
Lessons for your own Mk1
- Prove the engine first. A bench run tells you whether a donor is worth building a conversion around.
- Spark, fuel, compression. Check each in turn and a first start isn’t a mystery.
- Check the colours. Later Ford wiring colours may not mean what you expect.
Mk1 context
Twin side-draught carbs are a classic Mk1 look, and this test shows a Zetec can run on them with a carb-era Ford ignition module, at least on the bench.
Related
- Series page: the Dave’s Garage Zetec RWD conversion, episode by episode
- The previous video: Episode 2, a home-made water rail from box section
- Where the sump story starts: Episode 1, a DIY oil pickup pipe for the ST170 sump
- All our Mk1 Escort builds