Reply at bottom of message is from another thread on this NG!
"Dave White" <
[email protected]> wrote in message
news:
[email protected]...
> In <[email protected]> Jens Axboe wrote:
>> On Wed, 19 Jan 2005 13:04:10 +0000, Richard wrote:
>>
>>> Assuming the cam is knackered what is best to use. A standard cam or
>>> a 'mild' road cam or other? On RPi's site they have a cam that it
>>> says is suited to autos http://www.rpiv8.com/engine-6a.htm(RP4) is
>>> this anygood or bull? Its only used on road and very rarely for
>>> towing. I have put a mild cam in our 90 V8 but its hard to tell the
>>> differance as the engine was worn beforehand. Richard
>>
>> 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?
>
> 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.
> http://www.yorkshireoffroadclub.net/
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.
www.bhengineering.co.uk
www.roverv8engines.com
