Practically Classics Forum

I can't seem to find what engine oil to run in my Rover V8? Its now in my MGB but was a 3.9 EFI unit that came out of a 1993 Discovery.

What grade oil is correct for this motor?

'ello,
you can use 10w40 in all of them without issue unless it is a high mileage / on it's last legs or the oil pump is worn. (or your rocker shafts are knackered and letting pressure bleed away as I experienced recently with my new steel rockers eating the shafts)
Earlier and higher mileage engines can use 20w50, later (suffix B, with the serpentine front cover, crank driven oil pump, cross bolted main bearings, re-designed crank, etc) engines have tighter tolerances and (MUCH) better oil pumps so there is no need for a thicker oil. 1994 is the change over year so your 1993 is almost certainly a V belt engine but if you have landed a "4.0" even if you have fitted an earlier front panel should stick to 10w40.
I'm sure John and others will be able to give some more detail but because of the flat tappet design of the Rover V8 you need an oil with Zinc alkyl dithiophosphate in to reduce cam / lifter wear.
Castrol claim their oil does contain the correct amount of zinc and phosphorous for rover v8 engines or you can get an additive to put it back in to your choice of oil.
If your engine is using a new cam / lifters (if it isn't then I would as they are fairly cheap and always wear quite badly) then make sure you use a break-in additive and run it at 2k for 15 minutes or so to harden the cam / lifter faces.

Thanks Terry!

10W40 it is then. Semi or fully?

I use semi Castrol 10w40.
If you are going to drive it "enthusiastically" then race oil such as this:
http://www.ebay.co.uk/itm/MILLERS-SYNTH ... 0468333036
contains a higher level of ZDDP to keep wear to a minimum.
40,000 miles (and having had the top end of mine apart recently) with Castrol and there is no significant wear to mine so it can't be too far wrong, I do change the oil every 3000 miles.

Whilst I agree, generally, with TerryG's suggestions, it's worth bearing in mind that other manufacturers, such as Shell and Mobil, market similar products. As long as the oil conforms to the ACEA oil specs A3/B4, you will have adequate protection for normal motoring. But if, as Terry implies, you intend to race or thrash your car, and the addition of extra ZDDP to protect against high temperature shear becomes desirable, be aware that your expensive cat. converter will become contaminated and require replacing the sooner.

Pavel

Pavel wrote:....your expensive cat. converter will become contaminated and require replacing the sooner.

Pavel

A Henry VIII isn't required on the O/P's car, which is an MGB with a large surprise in the engine bay.
One of those things that works both ways for yet neither against; if the engine is older than the car, then emissions are tested according to the age of the engine but, and this is the good bit in this case, if the car is older than the engine, it's the car's age that dictates the nature of the emission or smoke test.

So if the O/P had fitted a pre-emission testing 1800cc B series to the Disco, the Disco would need only a visible smoke test because of the engine's age, thank goodness he's done the swap the other way round!

Thanks guys,

Done a little research and going to go with Shell Helix Hx7 10W40 Semi. I'm not a Castrol fan but also it seems from what I can find that Hx7 has a slightly higher ZDDP content than the Castrol (1200-1300ppm compared to 800-1000ppm).

Don't think it matters too much. It's a Land Rover engine so it'll all leak out anyway..

Good thinking, Welshie. My son has an early Rangie with the 3.9l and uses that oil -- no worrying leaks!

Pavel