Difference between 4.0 and 4.6 Engines

[SGaynor]

New to LRs...just bought an 03 Discovery HSE. This one has the 4.6L engine.

Simple question: What is the difference between the 4.6 and previous 4.0L engines? Same basic engine, just bored/stroked to larger size, or was it a total redesign?

Thanks.

 

[HunterAK]

New to LRs...just bought an 03 Discovery HSE. This one has the 4.6L engine.

Simple question: What is the difference between the 4.6 and previous 4.0L engines? Same basic engine, just bored/stroked to larger size, or was it a total redesign?

Thanks.

Same engine... different displacement... not a total redesign... same V8 it's always been!!

 

[frickjp]

Different crank, rods, pistons, cam, ECU software.

 

[ptschram]

Different crank, rods, pistons, cam, ECU software.

Crank: Same size journals as a 4.0, different stroke.
Rods: Same size wrist pin and bearing size, different length
Pistons: Different diameter, different compression height.

Cam? Didn't know it was that much different from the others.

ECU software: Different fuel map to take better advantage of the greater displacement.

 

[frickjp]

Cam is a different part # 4.0 cams have orange paint on the end, 4.6, blue. WTF does that mean? Who cares? D&D is the way to go anyway.

FTR, the ECU has no problem adapting to the long term difference. After a while, LTFT is near zero anyway. If it was a big issue, it would be other than zero. Same situation with GEMS. (CUX is too stupid to let you know). Regardless of what the know-it-alls will tell you.

 

[jaacina]

The 4.0 and the 4.6 have the same bore, so the diameter is the same. They have different compression heights though due to the rod length.

 

[Discotec]

Can you use a 4.6 engine in a DI by changing over the heads and induction system, will the electrics hook up ?

 

[jaacina]

Since most of the electronics are in the induction system. Just need to make sure you re-use the timing chain cover and correct timing gear. It has been done a number of times.

 

[Discotec]

Since most of the electronics are in the induction system. Just need to make sure you re-use the timing chain cover and correct timing gear. It has been done a number of times.

Thanks James.........:bigok:

 

[D Chapman]

Since most of the electronics are in the induction system. Just need to make sure you re-use the timing chain cover and correct timing gear. It has been done a number of times.

Have to change the crank position sensor and bracket, too, if your going GEMs a Bosch motor.

 

[SGaynor]

Thanks for the answers...was just looking to understand if the vagaries of the 4.0 translated over to the 4.6...

Now I know...