RV8 3.5 > 4.6 + stroker advice

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Kit
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RV8 3.5 > 4.6 + stroker advice

Post by Kit »

Hi all,

I'm after some advice, I want to build a 4.6 to go into a Defender but ideally I want to avoid all the 4.6 electrics sensors...etc as it's going onto a comp safari racer which will have some rough and tumble.

I have a 4.0 P38 and 3.5 EFi RRC which are laid up, so I can take parts off them?

What would you recommend?


1988 Range Rover 3.5 efi - Trials project

garrycol
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Post by garrycol »

Start with the 4.0 as it is the same block as the 4.6. Just put the 4.6 crank in, use the 4.6 conrods and for a higher compression ratio us the 4.0 pistons and go from there.

Garry

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Post by Kit »

Thanks for confirming Garry, where can get a 4.6 crank/conrods for a good price new/used?

What parts would you recommend to manage the ignition?

Ideally I would like to run it on EFi:
Would it be a massive pain to keep the 4.0 EFi?
Would I be better using the EFi off the 3.5?
Webber 500?
1988 Range Rover 3.5 efi - Trials project

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Post by DaveEFI »

If you intend going EFI, what sensors are there you wish to avoid?
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Kit
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Post by Kit »

Mainly the MAF, I'd probably replace it with a air temperature sensor if I ran a MS2
1988 Range Rover 3.5 efi - Trials project

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Post by ChrisJC »

The 4.6 sensors will be much newer than the 3.5 sensors.

I would do as suggested above to get a 4.6 engine. I would probably ignore the 3.5, but I would research what sensors are needed for your preferred fuel injection system, and choose the inlet / ignition system that suits you best.

Chris.
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Post by garrycol »

Kit wrote:Thanks for confirming Garry, where can get a 4.6 crank/conrods for a good price new/used?

What parts would you recommend to manage the ignition?

Ideally I would like to run it on EFi:
Would it be a massive pain to keep the 4.0 EFi?
Would I be better using the EFi off the 3.5?
Webber 500?
Note that I am in Australia so I cannot help where you would get a crank etc - noting how are you going to get a 4.6 engine without a 4.6 crank.

If you are confident with Mega Squirt then go with that for ignition and injection but if you are new to it, it is not as simple and people make out

You can run the 4.0 EFi system but work will be required on the ECU to make it run stand alone (I have assumed it it a Thor system - not sure about a GEMs system. It will run the ignition as well.

I would forget anything off the 3.5. I have heard the Webber works OK but you will still need something to run the ignition.

Garry

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Post by DaveEFI »

Kit wrote:Mainly the MAF, I'd probably replace it with a air temperature sensor if I ran a MS2
Ah - right. But a MAF is common to most factory injection systems including most RV8s. The first RV8 EFI used a flapped AFM, which is definitely to be avoided.

As you say, MS doesn't generally use a MAF, but uses a combination of engine vacuum and throttle position for much the same thing.
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