Thread: Which Cam?

Originally Posted by Traco

Which cam for a hc 4.6 with hotwire injection and a Mark Adams Tornado chip in an auto Disco1?

The ones I'm considering are: RP4 (Piper) or the new Cyclone (Real Steel). The Cyclone is supposed to pump out an extra 27ftlb on a 3.9. Both are made for shifting heavy 4x4s with auto trans and have a good idle, so the emphasis is on torque more than outright bhp. The RP4 (from RPI) has a good reputation from those who have used one.

I am also looking at Crower and Speco cams. Discounted the Dynotec 216 that Sydney Speed Suppliers and TRS sell after reading some reviews about premature rounded off lobes on a Commodore forum.

The Dynotec PC216 or PC217 are fine, and I wouldn't listen to what those Commodore types spout on about...I've fitted plenty to Rover V8's and have had NO issues with lobe wear etc.

JC

are you still running the front 3.9 Timing cover? When we built my 4.6 I got hold of the full 4.6 front timing cover and set up Wolf with Coil packs, When it came to the cam there were nothing much available in Aus and quite pricey and limited options O/S, as the 3.9 cams wont fit !

How are you setting your 4.6 up ?

I'm using the 3.9 front cover so I can retain the dissy, but with the crank driven oil pump of course. Need a cam without too much overlap for efi but which will work with auto transmission and provide truckloads of low to mid range torque. At the moment I'm tending to lean towards the Piper RP4.

I've been talking to Mark Adams about a Tornado chip for the 14CUX. This is a fairly common upgrade in the UK as the price and availabiltiy of new 4.6 engines makes it reasonably affordable. So it's realtively easy to get a chip done that results in 10 -15% more torque and maybe even some small fuel economy gains.

In addition you can select other preferences such as idle speed, rev limit, etc.

Tornado Engine Management Systems need to know some basic type information from inside the ECU. There are two major variants, and the software has to match. Also it is worth checking that the EPROM in your ECU is fitted in a socket, because many of them are soldered into the circuit board. If this is the case then you would need to have one fitted locally, or send it to TEMS for surgery.

A chip is about half the price of an Interceptor (Unichip) and much much less than going for another full engine management system (Emerald, DTA,etc).

Either MCT or Coscast/Mahle 4.6 blocks are available new.

I put a new hc 4.6 in my hot SD1 Rover sedan a few years ago (worked Buick 300 alloy heads, Crane cam, Edlebrock carb, etc) and have not had any problems with the block. However this runs at 74 degrees whereas the fuel injected Disco has an 88 degree thermostat. If you put in a colder one the ecu pumps in more fuel (the enrichment cuts out at 80 degrees).

The Coscast blocks that RPI are selling are a completely new casting (by Cosworth) and look good but are pricey. Also they haven't been around long enough for any problems to show up yet. I'm reluctant to use the MCT made standard Rover type casting due to fears with cracking/slipped liners on a fuel injected engine (though it seems the GEMS ones are more at risk).

So I'm on the look out for a seasoned (well used) P38 block that has been top hat linered. Anyone know of a source of these in Oz?

Hello Traco,

If you are still on the look out for a top hat linered 4.6, have a word to Graeme Cooper Automotive here in Sydney.

I purchased my seasoned Thor 4.6 with top hat liners from them, absolutely excellent!!

Ron.