“Hammering along in a 30-year-old Land Rover is actually rather fun”
way I do things is not the only way, or even the best way.
I’m always open to new ideas, and so when I got a call asking me to take a look at an ex-army Land Rover with a 200Tdi and a few issues to resolve, I was intrigued to see what I would find, and rather hoped there would be a few ingenious solutions to the installation that I could learn from (read steal).
No such luck. The fault list read: poor performance, smoking heavily, leaking oil. It didn’t take long to work out why. As I mentioned earlier, one of the problems with a 200Tdi conversion is the flywheel housing.
The Discovery and Defender versions of the engine use the same basic casting, but the Discovery has one of the bellhousing studs in a different place, the three bottom studs missing, and four long bolts at the bottom, which sandwich the flywheel housing between the bellhousing and the cast aluminium stiffener that sits between the cylinder block and the sump.
On the Defender version these four bolts are replaced with Allen bolts recessed into the flywheel housing.
So, to convert a Discovery flywheel housing to Defender specification you need to drill and tap four holes to take M10 threaded studs (helpfully the holes are already partly drilled), counterbore four more holes to take Allen bolts, and pull out (or drill out if seized) the two locating dowels that are unique to the Discovery version of the housing. Or you could do as the perpetrator of this conversion had done, and use the flywheel housing from an old 2.5 diesel.
Yes, it fits the 200Tdi: the attachment bolts, dowels and crankshaft seal are all the same. Yes, it will mate up to the LT77 gearbox with no modifications: that is the application it was designed for. But...
Firstly, you lose the four long bolts that go into the block stiffener. I tend to take the view that Land Rover usually did things for a reason, and if they felt it necessary to bolt the flywheel housing to the block stiffener I am not going to argue any differently.
I suspect that the bolts are there to stop the flywheel housing from flexing slightly and pulling away from the block: I don’t know this for certain, but I have seen several 200Tdi conversions with these bolts missing and oil dripping from the block to housing joint.
Secondly, on the 200Tdi engine the injection pump is timed with the engine at top dead centre (TDC), number one cylinder on the compression stroke. Accurate timing is crucial on diesel engines – even a couple of degrees either way can make a huge difference to the running.
The Tdi flywheel housing has a threaded hole in the bottom: a timing pin (or old R380 gearbox reverse light switch) is screwed into this hole until it engages with a notch in the flywheel, at which point the engine is at TDC. The older 2.5 engines are timed in a different