Discovery 2 4.6 v8 build help!
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Interesting, so if I blueprint it to 10:1 that should make a difference. I then need to choose nice heads as I'm not up for porting them myself. I was looking at some v8developments stage 3 heads as I'm not sure stage 4 would benefit it any further. I've also been researching about merlins but seem to have some fitment issues; exhaust, rockers touching covers etc. Best cam to use in this application? What's everyone running in theirs? I think I'll get some hedman manifolds for it too. How much torque do we think this set up could produce?
Land Rover discovery 2 top hat 4.6 v8 4.0 pistons stage one heads Kent h200 cam Range Rover maf Mark Adams remap in lpg
That's good to know. Is the reason I can't go too high on the compression with a high torque camshaft because there isn't much duration therefore the cylinder pressures will be a lot higher than they would be with a high duration cam? What sort of torque figure do you think I could achieve with that?
Land Rover discovery 2 top hat 4.6 v8 4.0 pistons stage one heads Kent h200 cam Range Rover maf Mark Adams remap in lpg
If you have a cam that allows early cylinder filling like a torque oriented camshaft you need a lower compression, if you have a high revving engine you can use a power oriented camshaft with more duration, you are correct in thinking that a torque camshaft will not work with high compression
With high compression you need overlap to run on regular fuel. You should aim for a lower compression and less cam to achieve what you want.
With high compression you need overlap to run on regular fuel. You should aim for a lower compression and less cam to achieve what you want.
Intake I'm thinking of just keeping the banana branch Thor manifold and the exhaust I'm going hedman 4 into 1 they have 1 1/2" primaries and a 2 1/2" collector. After them it will be sport cats and a free flow silencer all in 2 1/2"
Land Rover discovery 2 top hat 4.6 v8 4.0 pistons stage one heads Kent h200 cam Range Rover maf Mark Adams remap in lpg
Is the Thor inlet different between the 4 and 4.6? Seems odd BMW would have gone to those lengths yet restrict the max BHP? I understood it was done for maximum torque. If after BHP, you might do better with the old inlet system?
According to a mate who has one, the Thor is very good indeed at doing what it was designed for - ie a 4x4. So might be the law of diminishing returns trying to improve it?
According to a mate who has one, the Thor is very good indeed at doing what it was designed for - ie a 4x4. So might be the law of diminishing returns trying to improve it?
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
The heads and ports are pretty much the same as the 3.5 Vitesse - Why go to all those lengths!! - they didn't go to any lengths at all apart from what they needed to do to get through the legislation on emissions required at the time.DaveEFI wrote:Is the Thor inlet different between the 4 and 4.6? Seems odd BMW would have gone to those lengths yet restrict the max BHP? I understood it was done for maximum torque. If after BHP, you might do better with the old inlet system?
According to a mate who has one, the Thor is very good indeed at doing what it was designed for - ie a 4x4. So might be the law of diminishing returns trying to improve it?
They had no intention of carrying on with that engine so they did the bear minimum they needed to as the manifold only needed to flow the paltry amount of air to feed the ludicrously low power output of the stock 4.6 .
If you want more than just stock performance out of a RV8 every aspect of the induction needs to be modified.
4.5L V8 Ginetta G27
Think I am going to enquire about extrude honing. I think it's the only way to truly open up the Thor manifolds. Who do people recommend when it comes to top hat liners? I have seen that v8 developments do it. Think I'm looking at about a grand to do it but I'm not going this far with out doing it!
Land Rover discovery 2 top hat 4.6 v8 4.0 pistons stage one heads Kent h200 cam Range Rover maf Mark Adams remap in lpg