Not sure if this is new thread worthy, but I'm going for it.

Broke down 2 Bosch 4.6 motors today. a 2004 D2 and a 2001 RR P38(Red block), both motors had around 130K on them.

Not sure if its because I know the RR block is superior, but it looked so much better.

D2 motor had a steam cleaned cylinder and walked bearing. All the tolerances were loose and the motor seamed to slide apart.

P38 motor was tight as can be, a pain to get the pistons out and the cam was in there good.Could the Cam bearing journal on these "superior" red blocks be better than the others? I know the cylinder wall thickness is.

Check out the bearing with a nice hole from the lifter!

 

I had never heard of a walked bearing before yesterday. Astonishing.

I think older D2s suffer from lack of maintenance where rangies make more trips to the dealer. Just a guess. True for mine, for sure (only been to the dealer once in sixteen years).

 

There is a book "how to power tune a rover v8" that explains how in 97' LR started grading there blocks. Best quality were marked as red blocks and send for 4.6 builds, blue the lowest quality was used for 4.0.

Meaning RR 4.6 blocks are the best.

By 2003/2004 they were only making 4.6 motors so they used whatever blocks they had for the build. That is why so many 03/04s have issues.

 

So if I was to do a rebuilt engine, I should start with an 01 RRC 4.6 block.?

 

Has to be a 4.6.

For Bosch you have 01' and 02'. Also some late model 99' RR were Bosch.

You can also use a GEMS 97' and older but need to modify the CPS mount and knock sensor mounts.

But needs to be from a 4.6 RR, best quality.

 

 

Amazing. The dealership failed to inform me that my Disco probably had a crap block.

 

The book goes on to explain that the red blocks were reserved for 4.6 motors, but as explained by 03/04 that's all they made, so it was s crap shoot.

 

I like how the lifter even got in on the action of eating that bearing

 

your giving away all the secrets; Man.