twin turbo 4 litre rover v8.

[andrew e]

I finally got a spare motor for my defender buggy so i can play around with some hairdriers. It started when my old man turned up with a 2004 disco which had an under bonnet fire, with minor damage to the engine. The bosch intake manifold is ok but the injectors are toast, as is the coil pack. The bottom end should be strong enough. I'm planning on using some turbo's off some jap 2 litre junk, which are cheap, spool up quick, and aren't watercooled (less to go wrong). No intercoolers yet. I'll use 2 head gaskets on each side, to lower the compression (any opinions on this?). The origional throttle body was toast, but the front half of the manifold unbolts, exposing the intake runners on each side, prefect for a twin throttle body setup. Any reccomendations on what injectors, what computer, and what size throttle bodys? Is it worth scorcing another coil pack and running it without a dizzy for waterproofing?



sandblasting tomorrow.

Andy

[nzdarin]

I don't know what shape the combustion chamber of a rover is but in general 2 head gaskets (or a spacer etc) to drop compression will reduce the quench and so increase the chance of detonation. You want to keep the piston hieght as high as possible around the edge and reduce it in the centre to lower compression ratio. That is why you would normally dish a piston.
What compression is the rover in stock form?
What sort of power can the rover bottom end handle and what is you plan? What boost do you need to run to get that power and at what revs? ECU is pretty easy as there are a lot of options but the more you spend the more reliable it will be and you'll be able to run higher boost to compression ratio, safely! That's why I have an Autronic ECU and CDI in the truck. Coils will depend on what else you do. I'd talk to whoever is going to tune it for you and get their reconmendation. (same goes for the rest of the electronics)
No dizzy is great idea! Also you use a CDI instead then you have total ignition control to allow the higher boostand stop detonation.
Injectors are pretty simple as well. I assume the rover uses standard injectors and so you can get second hand ones of pretty much any size. Rotaries are a good place to start as they run a much bigger injector than most but in reality you probably only need a 400 too 500cc injector. In you are going to get new fuel rails then I'd work on making sure you can use standard tp feed injectors as talked about above.
Why no intercoolers? Cheap easy power and much better engine life accordingly. For the few hundred $ a couple of cheap IC's will cost I'd do it straight off.

I could go forever as there's a huge amount to do this correctly. You can throw a coupl of turbo's on but unless you do it properly you may as well not bother. Think about what your budget is, double it and add some and you'll be getting close to what this will actually cost you. SERIOUSLY!

PS That manifold does look like an easy twin TB conversion!

[chimpboy]

CR is probably only 8:1 to start with.

http://www.british4x4.nl/TheSpecialist/8cyl.htm

If you kept boost under 6psi you would probably just about get away with it with just a slightly thicker than standard head gasket..? But you'd be running premium unleaded for good. Anyway maybe you could experiment this way and then look at replacing pistons later if it seems worth it.

Just random thoughts, I know stuff all about turbos.

["CANADA"]

Chances are, anything above 7-8 PSI you will forever be blowing rear mains and breather hoses off...


Do it properly if you are going to do it...What does it redline at?

[BrettInUte]

my mate has done this.
440 hp with 2 throw away turbos on 3.5L motor.

pm me.

[GRPABT1]

Twin head gaskets will give more trouble than water cooled turbos.

[andrew e]

its the good bottom end, 4 litre late model is meant to be the strongest with 4 bolt cross drilled mains. Was thinking 7-8 psi.

[Dexter]

I would probably suggest some ebay turbos(chinese) because second hand turbos are a minefield.

[frp88]

Don't double the head gasket if you running 100 octane fuel and the comp. is only at 8:1 7-8 psi should not be a drama.Asked Chris he ran a 4l lexus on 8 psi and he was spinning the 37 like there was no tomorrow feel 400 hp is more than enough unless you are doing desert racing.

[PGS 4WD]

I relieve the combustion chamber and retain the std thickness head gasket, careful work on the head will lower the compression and increase flow around the valves if done right while maintaining the important quench area around the edge of the bore.

Joel

[andrew e]

I relieve the combustion chamber and retain the std thickness head gasket, careful work on the head will lower the compression and increase flow around the valves if done right while maintaining the important quench area around the edge of the bore.

Joel

any photos of before and after?