V8 cam

Hi Richard,

Too bad no one has answered this one yet, I was contemplating using that very same cam on my Disco.

Anyone used the RP4 and cares to share?

Regards, Jens

I have fitted two 3.9 EFi auto setups into Defenders in recent years. Both automatics.

One of them has a standard Land Rover 3.9 cam in it, the other (the lower mileage one) has an RP4 fitted.

There is no noticable difference between the two, if anything the one with the standard 3.9 cam seems the better of the two but it's borderline. If I were to put another new cam in at some time in the future I'd probably go for the standard cam as I don't think the RP4 justifies the extra cost. Unfortunately it's difficult to compare the two cams in the same engine - the engine now fitted with the RP4 started out in a Range Rover and I rebuilt the engine as part of the transplant into a Defender. Given the aerodynamic differences and the slightly larger tyre size on the Defender it's difficult to judge.

I'd always go for the duplex timing chain and, if you're going that far, a main bearing stud kit. Use a composite valley gasket and, if you're taking the heads off, get them skimmed and use composite head gaskets.

cheers

Dave W.

Personally, I'd plump for a Real Steel Viper Cyclone, that cam is designed specifically for the 3.9EFI engines (including automatics, that otherwise have serious stalling when selecting gear issues when you fit a different cam) and with no other mods will give about a 10% increase in torque across the board with about an extra 15bhp at the top end. I've used it in a few engines now and it "does what it says on the tin"! It works really well in conjunction with a rising rate adjustable fuel pressure regulator to iron out any slight flat spots due to the std lean fuellng. A lot of cams make serious claims re. power gains, but you really need to consider that in a landrover product you need torque, not necessarily power. Most fast-road cams will give an extra 20bhp or so, but about 500rpm higher than the std peak power rpm, with less power than std below around 3500rpm. Great in a 2-seater roadster but rubbish in a rangie etc unless you drive at the redline permanently. Stick with the cam quoted above, or an equivalent such as RPI's RP4 cam. Just don't be taken in by rpi's bullsh!7. Be wary of claims about even mild-road cams such as Crane H-204, Piper

270/110, Oselli RV8255 (an excellent cam grind for landy's) as they were all designed for carburettor engines and the EFI systems will not simply compensate to the extent required. Make sure you check the lifter preload and shim as required for best results. Badger, B.H.Engineering, Rover V8 engine specialists.