I am going to start shopping for a new engine due to a cracked block. Is the 4.6l swap worth the extra money? Am I going to need an ECU out of a 4.6l car or is my stock ECU going to be able to adjust to extra displacement? Is there anything else that is different on a 4.6l such as injectors or MAF? If I buy just the short block, can I use my 4.0l heads on it?

 

4.6 and 4.0 Bosch are the same block, different stroke. Heads are the same all the way around, no need for another ECU, everything bolts up the same. There are a few things to consider if you are swapping from a GEMS, but only a few.

Be sure that if you are swapping a used engine that it is not from an 03.

 

I looked into this not too long ago(before I needed a new tranny). In my '98, it would have been a direct swap. Only thing to change was a chip in the ecu to up the injector flow for the bigger engine. In older(pre-97) disco's, the 4.6 would need to be converted to distributor type ignition. Here's a link with some info, and if you contact them, they got all the info and parts you may need

http://www.eastcoastrover.com/116.html

 

Sorry, but in your 98 it would not have been a direct swap. You have to modify the knock sensors to fit, and the front cover has to be changed to a GEMS, or you have to go with spacer, an electric fan, and new timing gear set. The engine would have to be converted to GEMS, as the only Rover 4.6's were Bosch, or had accomidations for a distributor for the PRE-96 Discovery.

 

You will need the 4.6 ECU, it will run fine on the 4.0 ECU but you wont get the gain in power without the 4.6 ECU.

 

Unless I'm mis-understanding you, I know 1998(but i believe it is '96-'98) P38 Range Rover 4.6HSE came with a 4.6 GEMS non-distributor engine. East Coast Rovers told me one of these would bolt right in with no mods, save for an ECU chip.

 

You are correct Kenk, the P-38 was GEMS and had the 4.0 and 4.6.
They did not start using BOSCH engine management until BMW took over.
German's wanting to use German stuff and all.

 

Discoart, What year is your Rover? I was thinking about finding a good 4.6 for when my 4.0 finally dies. Mine is a 2000 series 2 with 175,000 miles.

Willie

 

Mine is an 02.

Has anybody driven both, the 4.6 liter and the 4.0 liter disco? Is the difference in power worth the extra $1.5K?

 

Being local, send me your number and I'll call you.