Thread: Old school V8i tunning

For more torque and not silly $$$$'s, I'd start with a camshaft swap, upgraded fuel pressure regulator and a new ECU chip / interceptor box.

Jon

beyond that you could look at gas flowing / porting of the heads.

Sure they are available off the shelf.

I would be inclined just to opt for a different camshaft, one that has been designed to increase torque.

Modifications to the heads will usually shift the torque curve further up the rev range, which is the opposite to what you are seeking, especially with an automatic.

The biggest improvement for torque though is capacity, so going to a 4.6 would produce a massive improvement, but at the same time far greater cost.
It is not just a matter of swapping the crank either, as a 4.6 crank will not fit into a 3.9 block,...you would be looking at a whole new engine.

So the camshaft, lifters, timing set and rocker assemblies would be the way to go with minimum outlay.

Ron.

A Hiclone

The cam is likely to have some wear and power has probably dropped off unnoticed over time. A new cam and chain would be the go and replace the head gaskets while the inlet manifold is off.

I've looked at the specs of several of the hi torque cams and they dont look much different to a stock cam, but having said that, I've never tried one.

Defender transfer gears would also make a big difference to torque at the wheels......

if your pulling the heads of and want to work them up...

change the camshaft,
new valve gear
extractors
if your heads will take it skim them to lift the compression ratio

then (and you can do this without lifting the compression ratio and still get improvements

get the heads and manifolds port matched and flowed to suit your new setup
new brain + injectors to suit the lot.

leave it alone, it works.
if you mod it it becomes a bastard and is impossible for it to be fixed by the man in the bush where it is most likely to break down.
if you arn't happy with the performance then buy a better vehicle.
that may be hard to do!
stroke it - your local mechanic is a tosser.
learn to drive it within the limits of its performance - it's a v8 for christs sake, how much performance do you want!!
and don't lose sight of the fact that the more you make the engine go, the more the drive train will need upgrading.
mr lr built a pretty good machine, and when we want more from it we suffer all the upgrades to solve the next breakage.
if this doesn't do the job for you, buy something else.

Originally Posted by RoverP6B

I would be inclined just to opt for a different camshaft, one that has been designed to increase torque.

Modifications to the heads will usually shift the torque curve further up the rev range, which is the opposite to what you are seeking, especially with an automatic.

So the camshaft, lifters, timing set and rocker assemblies would be the way to go with minimum outlay.

Ron.

I agree with the cam and assorted items but there is room for improvement with the heads and manifold. All that really needs to be done is match porting the intakes in particular and cleaning up inside radius at valve seats without removing too much metal.
Headers as per Blknight but interference type not collector unless you plan on running 12 sec 1/4 mile....
There is also a converter upgrade for the 4HP22 you can do using the 4.6 unit. See here for the link to ashcrofts. Not sure where the page is now, but Im sure you can email them and get them to send the info.