Blacktop? Silvertop? Good question.
The Zetec-E Engine comes in a few Series. Do not get this engine confused with the the 1.6 Zetec – S engine, as found in the mk5 fiesta and focus. It is a totally different design.
Series 1 – Silvertop – Upto 1995 ish, found in Escorts, Fiesta Mk3, Mondeo Mk1
-These come in 1.6, 1.8 & 2.0 variants. It has DOHC 16V cast into a aluminum rocker cover and has a known problem of sticking valves.
Series 2 – Silvertop – Upto 1998 ish, found in Escorts, Mondeo Mk1/2
– Again, they come in 1.6, 1.8 & 2.0 variants, but have 16V Zetec cast into the aluminum rocker cover. The issue of sticking valves is sorted here.
Series 3 – Blacktop – 1998 Onwards, Found in Focus Mk1, Mondeo Mk2
-This one only comes in 1.8 & 2.0 variants. The rocker cover is coated in black acrylic. There is also a 170BHP (Variable Valve Timing) version of this found in the Focus ST170.
The series 1&2 engines are almost identical from the outside, there are minor differences to the head, to combat the sticking valve issues. Nows a good time to mention that either of these are near a straight swap for a Mk3 16V Fiesta. In all variants, the block mounting holes a practically identical, which is what makes them such an easy swap for each other.
The series 3 engine is fairly similar when looking at the side by side, how ever all the mount bolt holes are laid of differently which causes a problem (amongst many!) when fitting into a mk3. It has a revised port design and the 2 piece sump tends to damp out some of the noise.
The main differences:
| Silvertop Engine | Blacktop Engine |
| Hydraulic Tappets | Solid Tappets With Shims |
| 32mm Inlet Valves | 33mm Inlet Valves |
| 28mm Exhaust Valves | 28mm Exhaust Valves |
| 1 Belt Tensioner (manual adjust) 2 Idler Pulleys | 2 Variants Of Belt Set up – Both Auto Tensioner -1 belt tensioner, 1 idler Pulley -1 Belt Tensioner, 2 Idler Pulleys |
| Waterpump Set Into Block | Waterpump mounted into housing on side of block. |
| Oil Filter Mounted On Back of Pump | Oil filter mounted to block |
| Deep Main Caps (with windage tray bolted to it) | Shallow main caps |
| Rod Legnth – 136.18mm | Rod Legnth – 141.01mm |
| Rod pin diameter – 13/16mm | Rod pin diameter – 19mm |
| Large Alloy Sump | 2 Piece assembley. |
| Crankshaft identical across the whole range | |
| Fibre Composite head gasket | MLS (0.6/1.1mm thick) head gasket |
| Power -1.6 – 90bhp -1.8 – 105/115/130bhp -2.0 – 136bhp | Power 1.8 – 115bhp 2.0 – 131bhp 2.0 VCT – 170bhp |
| Oil pump run directly from crank | |
| Inlet and exhaust stud patterns are identical across the rangle. | |
| Crank/Cam pulley gears are identical across range (except vvc variant, inlet is different) | |
| Recommended oil is 5w30 Semi Synthetic | |
| Sidefeed injectors | Top feed injectors |
| Inlet Manifold Series 1 – Cast Alloy (3 Power Variants) Series 2 – Plastic | Inlet Manifold Plastic, Focus and Mondeo are different items |
| ISCV – Cast inlet, iscv next to throttle on manifold – Plastic inlet, iscv underneath in manifold | iscv underneath in manifold |
| Crank drive belt pulley is the same accross all models | |
| Cam belt gears are the same accross all models (exception to inlet pulley on VCT 170 lump) | |
Things to note
– The MLS headgasket can be fitted to the silvertop series.
– The standard crankshaft can handle a lot of abuse.
– The Series 3 engines have revised ports.
– The series 3 engines known weak point is the cambelt tensioner, a manual adjust item is available from Ian Howell (Area6)
– Standard rods on all engines will take approx 300 BHP
– Dont be tempted to buy alloy crank pulleys that claim to give you x amount of bhp. The standard item is designed to reduce vibrations, if you remove it, you will send the vibrations into the oil pump and shatter the impellors.
– A known weak point of the Zetec block is the lower cylinder walls.
– A standard silvertop head flows poorly when compared to a standard blacktop head. However power can be produced from both.
– All thermostat housings are interchangleable, some have different thread sizes for temp sensors.
– The blacktop rocker cover can be fitted to the silvertop.
– Silvertop 2.0/1.8 130bhp cams can be fitted to silvertop 1.8 105/115bhp models for a power increase. Not to sure if the blacktop cams are interchangeable – anyone know?
– Solid tappets offer improved valve control at high RPM on the blacktop models.
– The ISCV from a blacktop engine will not work with a ecu designed for a silvertop engine. If fitting the focus manifold to a car using a silvertop ecu, use a iscv from a series 2 engine, plastic inlet, this should bolt directly to the focus manifold.
– Top feed injectors from a blacktop will work with a silvertop ECU
– Silvertop throttle bodys are all interchanglable. 2.0 items require slight modification when fitting to a 1.6/1.8. 2.0 and 1.8 130bhp throttles are the same diameter.
– The series 3 engines have two different lower sump and pickup pipe combinations, one for focus, and one for the mondeo (They ARE NOT mixable, you can use either on either, ie focus pickup and lower sump or mondeo pickup and lower sump. They will not physically fit if you mix them)
So why would i want to use the 2.0 blacktop over the silvertop, it produces less power and is a pain if fitting to a Mk3 Fiesta?
My answer to this is: Try and find a decent low milage 2.0 Silvertop, there hard to come by and when they are its expensive. For the 5 bhp difference i would rather have a slightly revised engine that can still produce good power when tuned correctly. Also, theres the option of the VVC 170 BHP lump from the Focus St170.
Something to consider about the power outputs of the to engines is that they both run different manifolds and both run different ecus. I””d say that its safe to say that focus/mondeo ecus are set to run for better mpg/less emissions. Thats most likely the reason for the difference in power outputs.
What ever engine you decide to use, there are good potential in both engines. The choice is yours!