Beat the Dead Horse again 4.0 to a 4.6

[Yellow Defender]

Greetings and a 30+ year Rover owner of many Defender, Disco 1.
To take a 4.0 to 4.6 I have a few questions can’t seem to find the exact answer on the forms.

It’s the same block and same bore (cast liners) block number HRC 2411
The 4.6 uses a different crank rod and pistons and GEMS ECU selected for the 4.6.

I have several pull out junkyard P38 engines and ECU. Can you tell by the ECU part number if it’s a 4.6L or not?
Attached photos are the rod (piston) and cam that not sure if a 4.6L


I’ve heard that if you have the wrong ECU (4.0L) , it will run very rich damage the freshly built 4.6L Engine.

Also, after research Bosch engines seem the have much thinner wall from casting just being long production over the years seems Bosh 99-04 engines had much more liner, slip and head gaskets and the older P38.
If you were to top hat liner on a seasoned block would you use an older 1995 4.0 or a 04 Bosch engine block for a rebuild?

Regards
Alan Dobbs

 

[robertf]

They run fine with the 4.0 ecu. My daily driver is set up this way

Id go with a crower 53229 camshaft over factory

 

[p m]

Also, after research Bosch engines seem the have much thinner wall from casting just being long production over the year

Who's theory is that?

 

[lunchbox]

I ran my 4.6 with a 4.0 tune for a while. You can tell the ECU that it’s a 4.6. It for sure ran better after I made the change.