Thread: Old school V8i tunning

Originally Posted by RoverP6B

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.
Ron.

But that is exactly what you want with an auto.
An auto has a thing called a TORQUE convertor. What this thing does is multiplies the torque of the motor. Therefore an auto produces huge amounts of torque down low. Since you have more than you need in the lower rev ranges, you are better off trying to raise the torque/power curve up in the rev range a little. Cams and other mods that produce low down torque are a waste in the auto and tend to take the performance away from the 2,000 to 3,000 rev range where it is really useful.

Originally Posted by JMAN

A Hiclone

Originally Posted by harry

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.

What a load of ****

Originally Posted by Blknight.aus

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.

Pretty much that, wlthough I'd can the extractors, the efi manifolds are good enough and the $ for HP ain't worth it, plus free flowing exhausts decrease torque

Next step, is working on ignition timing and aomething to control fuelling better, but you starting to add $$, so more imprtantly, what's the budget?

Im watching this with a lot of interest.I am thinking of doing the same thing except with a 3.5 V8 and auto.Sorry to hijack your thread but is it easy enough to change the cam with just the heads off?If you think your 3.9 is gutless come for a ride in mine Took Stirling out in mine last night after we put the new dizzy in and he says" Is that flat to the floor?". And my reply is "Yup it sure is". I would be looking at a cam which brings the torque down lower in mine and maybe a little port work because the Rover heads are pretty bad.

Originally Posted by SPROVER

Im watching this with a lot of interest.I am thinking of doing the same thing except with a 3.5 V8 and auto.Sorry to hijack your thread but is it easy enough to change the cam with just the heads off?If you think your 3.9 is gutless come for a ride in mine Took Stirling out in mine last night after we put the new dizzy in and he says" Is that flat to the floor?". And my reply is "Yup it sure is". I would be looking at a cam which brings the torque down lower in mine and maybe a little port work because the Rover heads are pretty bad.

Dynotec PC216 cam, some port MATCHING both exhaust and inlet, some EFI manifolds and a compression lift, head skimming and steel head gaskets. Don't machine too much due to the mismatch of inlet manifold angles and the need for rocker pedastal shims etc. PhillipA has some info about what heads/ chambers produce better comp ratios too, I can't rmember them of the top of my head.(Pardon the pun)

The biggest help would also be a remapped ECU. The difference with decent fuelling to these hotwire EFI engines is huge, and you can then run more advance etc... All of this without significant fuel consumption issues, even less if you don't push the loud pedal TOO much (As IF!)

JC

The biggest improvements are to be found in the heads, depending on your budget. TRS have the RPI big valve ported heads for about 2 grand or you can fit a pair of cast iron Buick 300 heads, enormous ports and instant bolt on power. There are a pair on the 'bay at the moment for about a $150 bucks, combined with a cam, mapping, exhaust, figures of 30-50 more hp are not unreasonable expectations. any more than that and be prepared to mortgage the house.

Originally Posted by rovercare

What a load of ****

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