Thread: Cylinder sleeve failure or something else?

Originally Posted by rover-56

May be worth considering vacuum impregnation in addition to new liners, top hat or plain, or pinned.

This may have some merit but I think everyone involved in the process would need to bring their A game. I see two problems here. One being humans and other being Land Rover.

If I had time and money to burn I would have given this a go. (money = be a multi-millionaire, time = retired in my mid 40s)

Originally Posted by ozscott

It is interesting how off centre the casts became. The machining marks per the video shown with the fighter planes evidence that...see the screenshot below and watch the vid for explanation. Deep castings near pushrods on one side and none at all on the other...so you can see how water jacket castings were so out of tolerance. Then see a photo of the valley from my motor which is a mid 90's 4.6...No such issues so it seems they went south after that. Cheers

The RPi is an extreme example of LR dodginess. Mine looked exactly the same as OzScotts. Mine was a 2003 motor (Biggin, if you remove the valley gasket I think yours will also look the same as Ozscotts). They were going south though for a while. The increasing in CCs was not just to make a bigger motor but to also compensate for the tolerances lost in Land Rovers aging tooling and castings. Basically the engineering science was deteriorating with each iteration in motor size (my opinion).

Originally Posted by Pedro_The_Swift

Theres a reason the 4L's fail,, look at Ozscotts post,, thats why these blocks werent made into 4.6's and shoved in expensive RR's,,,

No, that's not correct entirely. The stroke is the difference between the 4.0 and 4.6 (my understanding). Wall thickness is pot luck and a 4.6 is only marginally better. Recall the QA from Land Rover. Yellow, Blue and Red. Red indicating the thickest wall thickness and therefore these motors used in 4.6 assemblies. Yellow and blue going to 4.0 assemblies. If you were lucky (which is a stretch still being a Land Rover) you got a red tagged motor. 4.6 still have the same issues.

Originally Posted by Pedro_The_Swift

Dont waste money

Take a step back seriously and re-assess the entire situation is my advice. These cars are old, fuel economy is ****e relative to newer cars. Too many things to consider and some times flogging a dead horse comes to mind.

yep,, and all the 4.6's were red,, thats the reason behind the colour scheme,,
The top of the range RR's got the best blocks,, otherwise why grade them? ,,

the alternative is you pick a block at random, stuff a 4.6 crank into it THEN find out its wall thickness??


and in reality,, its probably much more likely to fail by just blowing a head gasket and cooking the old fashioned way

These are such good trucks (and really are the best of both worlds re Defender and modern Discos) that if you agree the answer is simple. You get an early 4.6 block. Get is tested by a machine shop and reconditioned and away you go. Or get a 4.6 and take the chance (not a significant chance) of problems and just stick it in as is and drive it.

Or go for a Marks Adaptors kit and a 6l ish LS motor, get it engineered and have a road burner.

Cheers

"No, that's not correct entirely. The stroke is the difference between the 4.0 and 4.6 (my understanding). Wall thickness is pot luck and a 4.6 is only marginally better. Recall the QA from Land Rover. Yellow, Blue and Red. Red indicating the thickest wall thickness and therefore these motors used in 4.6 assemblies. Yellow and blue going to 4.0 assemblies. If you were lucky (which is a stretch still being a Land Rover) you got a red tagged motor. 4.6 still have the same issues."

That's aparently correct, given that my 2000 P38 is a top of range 4.6.
Don't know what the repair cost, it was a warranty job by the previous owner.
I have the invoice, but the costings are blank.
Terry

My understanding is that by 2000 castings were going bad and there was a shortage of blocks. I would be comfortable buying any 4.6 4 bolt from mid 90's and using that (as I did) with no concerns.

Cheers

AFAIR the only problem with an earlier block to the Bosch block is that the mounting for the crankshaft sensor is different. I am not sure of that but I do know the sensor is different. I think the GEMS blocks have knock sensor mount holes .

All RV8 blocks are supposed to be "backwards compatible" with a few tweaks but by definition cannot be "forwards compatible".

The secret of all RV8s is to NEVER let them get over 100C. My 3.9 RRC had 240Kk on it when I sold it
and was never overheated and it was fine.

Regards Philip A

Just on blocks - Red tagged blocks are all 4.6, Blue tagged blocks are all 4.0, Yellow tagged blocks are either 4.0 or 4.6.

The paint marks do not seem to survive once the engine has been running for a while - I have both a 4.6 and a 4.0 block and neither have paint marks on them.

Originally Posted by Andrew D

This may have some merit but I think everyone involved in the process would need to bring their A game. I see two problems here. One being humans and other being Land Rover.

If I had time and money to burn I would have given this a go. (money = be a multi-millionaire, time = retired in my mid 40s)


The RPi is an extreme example of LR dodginess. Mine looked exactly the same as OzScotts. Mine was a 2003 motor (Biggin, if you remove the valley gasket I think yours will also look the same as Ozscotts). They were going south though for a while. The increasing in CCs was not just to make a bigger motor but to also compensate for the tolerances lost in Land Rovers aging tooling and castings. Basically the engineering science was deteriorating with each iteration in motor size (my opinion).

No, that's not correct entirely. The stroke is the difference between the 4.0 and 4.6 (my understanding). Wall thickness is pot luck and a 4.6 is only marginally better. Recall the QA from Land Rover. Yellow, Blue and Red. Red indicating the thickest wall thickness and therefore these motors used in 4.6 assemblies. Yellow and blue going to 4.0 assemblies. If you were lucky (which is a stretch still being a Land Rover) you got a red tagged motor. 4.6 still have the same issues.

Take a step back seriously and re-assess the entire situation is my advice. These cars are old, fuel economy is ****e relative to newer cars. Too many things to consider and some times flogging a dead horse comes to mind.

I agree Andrew, you would need the planets to align to be sure of a good job.
This is a gamble I can’t afford to take.
I’ll only get one shot at this before SWMBO gets really cranky. Not far to go on that score.
Looks like a good second hand motor from a P38 is the go.