I've got an Opel Manta (GT/E) coupe that was built by a previous owner as a rally car for UK tarmac stage rallying, with a Rover V8 engine fitted into it.
The donor for that engine would have been the Rover SD1 3500, single plenum 'flapper' Lucas injection system, distributor, etc.
Although it worked fairly well, the engine was exhibiting common failings that arise with that factory setup over time:
* Poor idle control, especially hot or when electric fan kicks in
* Flat spots, worst when using wide-open throttle from low revs; engine would bog down a lot before chucking the car up the road
* Misfiring some of the time; hard to pin down the cause even when new coil, plugs and other parts changed
Rather than continuing to replace various parts, some of which are no longer available new, chasing common problems, I went for the recommendation of fitting the MegaSquirt engine management setup. That decision was made a LOT easier given that the Rover V8 has had many conversions to MS in Land Rover/Range Rover off-roaders. The LR4x4 forums have a host of information, success stories and many gotchas and recommendations.
I bought a full kit of parts from Nigel at Megasquirt V8 Ltd, including new top-end parts to replace 'flapper' injection components with later 'hotwire' manifold, plenum and parts, as well as trigger wheel, sensor, EDIS-8 and Ford coil packs, and an MS1 ECU pre-loaded with an MSQ map known to work [safely] with a standard 3.5 litre RV8 engine.
A few differences found along the way where the Rover V8 injection differs slightly between the SD1 saloon and the Range Rover 'Classic' 3.5 v-belt engine but nothing insurmountable. For reference, these differences are:
* Injectors; the nose on the bottom of the SD1 injector is of a different size and design to other RV8 injectors - use injectors from the hotwire, or later, setup
* Fuel pressure regulator; there are a number of different fuel rails, use whatever seems suitable for your own installation
* Crankshaft pulley; there are less parts on the SD1 crankshaft pulley - I do not have power steering so even easier to remove unwanted pulley and fit the trigger wheel
* Crank sensor mount; as the crankshaft pulley differs, the bracket provided in the Megasquirt-V8 kit does not put the sensor in line with the trigger wheel - easy enough to space out differently or create a new bracket
* Heater matrix feed pipe; on SD1 it is from a pipe at back of the thermostat housing, below the inlet manifold - on the other V8s, from some other pipework (don't yet know where but will probably use manifold heater supply when I eventually plumb in my heater)
* Heater matrix return pipe; on SD1 it goes below the inlet manifold, not present on the RR manifold but can be bolted in place with original SD1 pipe and hose
Pleased to say that the conversion from flapper to hotwire injection parts was basically easy enough, and that the MegaSquirt setup worked straight off, as per Nigel's instructions.
Now, the engine starts reliably whether hot or cold, full throttle is usable from minimal revs, no misfiring evident at all and the engine seems much happier to shoot through the rev range. I still need to do some fine tuning and a before-and-after rolling road power run for comparison purposes but I can definitely say "MS Runs"
Links to information sources: