The V8 Owners Forum -

4.2 Rover V8?
Was it only fitted to the (early 90's) strange rover?
Are they an overbored 3.9 or something else?

Was it a problem engine?

The 4.2 was fitted the Range Rover LSE - i.e. the long wheelbase vehicle.

It's a stroked 3.9

Chris.

it also had a reputation for breaking cranks when tuned. No idea if if deserves this reputation or not but it wasn't a popular engine.

'it also had a reputation for breaking cranks when tuned.'

Yes it does. Usually as a result of no 4 main cap failing first. I have to say mostly on test beds though.

Russ

Cheers for the info

The 4.2 crank is actually supposed to be stronger than the standard items because 4.2 cranks were ground from the stronger "Iceberg" castings. The 4.2 engines themselves are probably not the best base for a modded engine, the off-set design of the pistons dosen't really lend itself to racing and the blocks of that time were crap even by rover standards. However I see no reason why the crank should fail if the engine is built properly. The cast cranks have held up well enough in some remarkable engines over the years and this is mainly because most people wont pay upwards of two grand for a forged crank in their rover. I'll be putting some silly hp + rpm's through a 4.2 crank myself in the not too distant future so I shall be ideally placed to comment on their durability (or lack thereof!).