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.

 

[special ed]

The difference will be compensated at the maf and O2 sensors. The computer just does its job and if it couldnt handle the change then you would have a check engine light. BTW ive done a 100+ of these builds with bigger cams and never neding anything to get it to run correctly. the computer just re adjusts the mixture to accomodate the 4.6. As for difference in the piston you can look at the top and the 4.6 has a deeper dish to retain the same compression as the 4.0. thats the easiest way to tell the diference. the piston on a 4.0 can be swapped onto a 4.6 rod to raise compression. And a final note on this thread is DONT use crower for a cam or lifters. Go with kent or piper.

 

[fishEH]

And a final note on this thread is DONT use crower for a cam or lifters. Go with kent or piper.

Why not??

 

[kris812]

On RobertFs ECU for GEMS app you can convert an ECU from 4.0 to 4.6 with a tick box. No clue what it does but it's there for a reason!

Also general OBD2 systems will compensate for a lot of things. Extra displacement or compression shouldn't change anything as long as injector pulses can keep the O2 within range. 4.0 4.6 4.8 it's all the same to the ECU, air just moves faster and pulses a little more fuel.

 

[efacewin]

On RobertFs ECU for GEMS app you can convert an ECU from 4.0 to 4.6 with a tick box. No clue what it does but it's there for a reason!

Also general OBD2 systems will compensate for a lot of things. Extra displacement or compression shouldn't change anything as long as injector pulses can keep the O2 within range. 4.0 4.6 4.8 it's all the same to the ECU, air just moves faster and pulses a little more fuel.

I need to deal with my GEMS ECU on my 96 Discovery with Manual trans. Your comment about the ecu App above indicates you may be able to point me in the right direction. The original ecu was replaced several years ago. The problem is that the replacement one is clearly configured for an automatic transmission. Would the app you mentioned allow me to change the Auto/Manual parameter?

Also, in addition to the “parameter” chip in the ECU board there is a “tune” chip. For the 96 manual, the correct tune chip should be labeled 9630. The tune chip in several ECUs I have tracked down have 9623 chips. This is referred to as pre-release tune chips in LR GEMS documentation. How in the heck can I find a 9630 tune chip? Any sage advice appreciated. Thx.

 

[boxster]

I need to deal with my GEMS ECU on my 96 Discovery with Manual trans. Your comment about the ecu App above indicates you may be able to point me in the right direction. The original ecu was replaced several years ago. The problem is that the replacement one is clearly configured for an automatic transmission. Would the app you mentioned allow me to change the Auto/Manual parameter?

Also, in addition to the “parameter” chip in the ECU board there is a “tune” chip. For the 96 manual, the correct tune chip should be labeled 9630. The tune chip in several ECUs I have tracked down have 9623 chips. This is referred to as pre-release tune chips in LR GEMS documentation. How in the heck can I find a 9630 tune chip? Any sage advice appreciated. Thx.

GEMS ECU UTILITY FOR LAND ROVER by robertf
does have auto/ manual buttons function.

 

[efacewin]

GEMS ECU UTILITY FOR LAND ROVER by robertf
does have auto/ manual buttons function.

I’m a technology person, but this forum is confusing to me! Could you send me info on how to get/use the GEMS ECU Utility? Thx.

 

[boxster]

I need to deal with my GEMS ECU on my 96 Discovery with Manual trans. Your comment about the ecu App above indicates you may be able to point me in the right direction. The original ecu was replaced several years ago. The problem is that the replacement one is clearly configured for an automatic transmission. Would the app you mentioned allow me to change the Auto/Manual parameter?

Also, in addition to the “parameter” chip in the ECU board there is a “tune” chip. For the 96 manual, the correct tune chip should be labeled 9630. The tune chip in several ECUs I have tracked down have 9623 chips. This is referred to as pre-release tune chips in LR GEMS documentation. How in the heck can I find a 9630 tune chip? Any sage advice appreciated. Thx.

GEMS ECU UTILITY FOR LAND ROVER by robertf
does have auto/ manual buttons function

I’m a technology person, but this forum is confusing to me! Could you send me info on how to get/use the GEMS ECU Utility? Thx.

Works with Android phone, get the app from Google Play, buy a ELM327dongle to sync up with the ECU. Pretty straightforward app.

 

[robertf]

those settings only affect p38 ecus that have chips with both 4.0 and 4.6 fuel and ignition tables. the discovery 4.0 only has 1 set of tables