Looking at changing my Dunnell 2.0L Zetec Silver top to a 2.0L Black top. Raceline can supply a crated motor at reasonable cost but what other bits will need to be costed as I understand some of the Dunnell parts will need to be replaced.
Has anybody done this 'conversion'?
What's the preferred ECU nowadays? (my Silver top runs the basic Dunnell Clubman 2D ECU)
As always, any helpful suggestions gratefully received

Did exactly this about 5 years ago. Silvertop had bit the dust at a trackday and it was cheaper to drop in a new Blacktop instead of either rebuilding the old engine or risking another (by then) old Silvertop.

It was pretty much a direct swap with a few exceptions, will try and be as accurate as my memory allows.

Off the Silvertop I used the following with no modifications:

Flywheel/clutch
Exhaust system
Inlet manifold
Thermostat Housing - Blacktop one is useless since it has no bosses for senders and is made of cheese

The following parts need some modifications:

Dunnell Sump - bought kit of parts from Scholar engines to fit Silvertop windage tray to Blacktop, cost £15
Oil Pickup - had to modify slightly to rotate it on the pump, easily sorted in the garage
The Off side silvertop engine mount fitted strait on, the near side need a simple mod to the top bolt area, easily done in the garage. Mine are Dunnell/Whiting mounts, others may need different mods.
Alternator - had to make a plate to allow the Silvertop bracket to bolt to the Blacktop, garage job. Bought Raceline idle pulley kit kit, other are available but it looks nice. Only works with engine covers off but there is no way a Blacktop will fit in a Caterham with the front covers on.
Had to replace some hoses but which depends on which cooling system you use.

I fitted the Silvertop cam cover, direct swap and looks way better than the Blacktop plastic fantastic.

Used the MBE management directly off the Silvertop. Minor remapping required.

Caterham Zetec
Great stuff - that's exactly the info that I needed
Just wondering though, what's involved in the sump mods?
How does the oil pick-up need modding?
What mod was required to the engine mount (I too have a 'Jimmy the Fish' installation)
and..
The idle pulley - is the change due to the cam belt route being changed?
thx

To answer your points one at a time:

No mods were made to the sump. The Scholar kit invoves changing number 2 and 4 main bearing bolts for Silvertop items with spacers under. This enables the windage tray to bolt to the extended threads exactly like it does on a Silvertop. Its as simple as removing 4 bolts and fitting 4 longer replacements.

The holes in the pickup need slotting slightly to allow it to turn a few degrees. I then made a simple lock tab and lockwired the bolts to prevent any chance of them moving. The alternative is the have it cut off and rebrazed.

The top hole needs to be about 10mm higher, simple fabrication mod.

The idler pulley is required because unlike the Silvertop there is no alternative waterpump that revolves the correct way. The idler pulley allows the waterpump to revolve in the direction intended by Ford. Legend has it there are impellers available in the States with the correct rotation that make the idler redundant, never seen one.

Any more questions please ask away.