6.3 AMG V8 engine conversion

[JLG]

Hi,

I'm considering converting my Defender 90 200tdi to a Mercedes AMG V8. It's been done with the wildcat engine so why not with a merc v8? Obviously engine n Gearbox mounts, radiator, fuel tank n fuel lines, propshafts, Gearbox and possibly bulkhead will need to be changed or altered. But what about the rear differential would that need to be uprated to cope with the power? Or would it be able to handle it? Is it also possible to swap the axles on a 200tdi to the newer tdci axles with the ABS brakes?

Thanks.

 

 

[Jamie_grieve]

I'd say it could be done with the right degree of enthusiasm. The end result might be easier achieved these days by the lighter and easier to install Chevrolet LS3.

The rear diff and half shafts will die but not straight away. It's the inertia of a heavy flywheel coming to a sudden stop that actually breaks things, not engine torque. You're just more likely to have spinning wheels finding grip with a more powerful engine so much will depend on your driving style. Axle upgrades are easy nowadays with Ashcroft and KAM components.

Have you done anything like it before?

[FridgeFreezer]

Neither differential will handle it, they couldn't handle the 200TDi reliably. I'd badger Nige / Hybrid From Hell (Xcess4x4) when he's back from holiday about what can be done for how much money.

Also worth having a serious wave of the tape measure before doing anything, car engines can be bigger in the wrong dimensions for a Defender engine bay and things like the PAS box, shape of sump, etc. can really ruin your day. Also remember the Defender engine is offset to one side.

[Daan]

Salisbury axle, like a 110?

[retropower]

As above an ls3 would make a lot more sense I think

[FridgeFreezer]

On 02/09/2017 at 7:03 PM, Daan said:

Salisbury axle, like a 110?

That gets you a diff that won't break, but the half-shafts are no stronger.

LSx makes more sense if you've gotta buy one, if you've got a spare AMG Merc that's been in an accident then the economics might stack up differently

[Carloz]

The standard running gear is not very solid to begin with, that is clear. So putting more power on it will break it faster. But you can drive fast or drive to break! ;-)

The rear axle and diff will stay alive in the same way as with a standard engine (with LT230) if driven in a "normal way" (if possible with a 6,3L V8... :-P)..

On the road: When really using the power in low gears the front wheels will slip and  the center diff. will die because of lack of lubrication.

Off road: diff. lock on, the wheels just slip. Diff's and axles will break when you overstress in the same way as a standard engine.

 

 

[Quagmire]

It won't just be the front wheels that slip on road- i can get 4 wheel wheelspin in my 90 and that's just with my little Rover 3.5!

When this happens the whole vehicle tends to start to bounce up and down as wheels spin/grip/spin/grip - when this happens it can't be doing anything any good at all... I hate to think how much the halfshafts are twisting in this scenario.

I think the result withe the 6.3 will be spin/grip/*pop* instead.

I do like the noise of the 6.3 though - it sounds evil. If you do carry on with the conversion please post it up! 

Good luck

 

[Carloz]

On ‎12‎-‎9‎-‎2017 at 10:18 AM, Quagmire said:

It won't just be the front wheels that slip on road- i can get 4 wheel wheelspin in my 90 and that's just with my little Rover 3.5!

 

 

With the centre diff locked I guess... With my RRC the front wheels just spin. (on the road so without diff. lock of course). Because of the short wheelbase a 90" will spinn the fronts more easily than a 100" RRC