4.0 vs 4.6
4th Gear
Joined: Nov 2012
Posts: 4
Likes: 0
All great info. Keep it coming.
From my reading this thread: the misfiring can't be due to sleeve, correct? kfx4001442 comment you can drive for long time prior other consequence. My concern is it will ware out the gasket faster than commented above, but no data to support it.
In regards to misfire, I did replace the plug with Bosch platinum plugs 5 month ago, but never replaced the plug wires. Therefore, will evaluate the wire, and the plugs.
From my reading this thread: the misfiring can't be due to sleeve, correct? kfx4001442 comment you can drive for long time prior other consequence. My concern is it will ware out the gasket faster than commented above, but no data to support it.
In regards to misfire, I did replace the plug with Bosch platinum plugs 5 month ago, but never replaced the plug wires. Therefore, will evaluate the wire, and the plugs.
Last edited by Keenan; Jun 28, 2013 at 12:08 PM.
Overlanding
Joined: Mar 2009
Posts: 20
Likes: 0
From: Southern California
Great thread, I'm in the current process of swapping my 4.0 gems to a 4.6 gems in my disco 97 and doing a complete overhaul, new cam crank connect rod bearings, cam shaft, lifters, piston rings, timing chain and sprocket, cylinder hone, redecking block and surfacing heads, valve job etc. etc.
About the slip liner it doesn't seem to be able to move or just slip if the engine isn't overheated or exposed to extreme conditions or block flaws. The slipping liners are heard of in the older engines from overheating where the liner just drops causing catastrophic failures and some newer motor of moving liners from over heating or the block cracks behind the liner allowing coolant to get into the liners backing. The newer motors has an added shoulder preventing a dropped liner in an event of overheating or extreme temperature changes, but again shouldn't move without some heat stress or block failure. The block is aluminum and the liner steel they do expand differently but should not be an issue unless its in extremely cold or hot environment causing one to expand or contract faster than the other or factory flaw with cracked block causing the liner to slip.
The donor 4.6l i picked up already went 130k and going 16years and the liners did not move and I don't think it will move anytime soon.
For others looking for the 4.6 and swaps I would say relax. I used to worry so much reading the forums from so called internet experts or rumors, but after doing tons of researching and speaking to expert shops that build race car and Baja race trucks its not an issue unless overheated and most people are weekend warriors or never really push their motors like racers do.
Again the 4.6l already went 130k and going 16years and the liners did not move and I don't think it will move anytime soon, so pinning it and top hatting it won't be necessary. It feels good but its an expensive mod that is not needed.
Find a 4.6l, if it doesn't have a slip liner leave it, if it has one top hat it.
Also to test for the crack block use torque plates and pressurize the water system to check for cracks. Usually its obvious with a piston, valve steam cleaned from coolant entering the cylinder.
I also recommend those who are doing the swap to do a complete rebuild, so far I rebuilt 4 rover motors and none are well maintained. If you are going to go through the effort and time build a reliable engine that you know you build and would be babied and taken cared of.
The donor motor condition:
Simple way to tell is any sludge build up? Remove the valve cover and oil pan and look.
Next check the crank bearings, is copper showing through?
Is the cam shaft unevenly discolored on the lobes?
When rebuilding don't half **** it by leaving old parts in like worn rocker arms, lifters, can shaft etc. As they will create lots of metal particles ruining the new parts.
A secret to extended engine life is using magnet as filters that attaches to your oil filter. You'd be amazed the amount of metal particle it captures. I have powerful neo magnet by the oil drain plug and around the oil filter.
I'm glad this forum is more lively and responsive, been to a few that was completely dead and quiet. I'll try to answer as much question as I can. I'm by no means claim to be an expert, just learning more everyday. if I'm wrong correct me.
I do have some questions myself as this is the first swap I'm doing.
Can the 4.6l oil pan be reused? Vs. The 4.0 pan ?
Can the 4.6l front cover be used? Some claims the 4.0 front cover must be used instead of the 4.6. Why ?
I'm sure its possible figment issues but I haven't tried dropping in the 4.6 yet to know. Still in the process of machining the 4.6
About the slip liner it doesn't seem to be able to move or just slip if the engine isn't overheated or exposed to extreme conditions or block flaws. The slipping liners are heard of in the older engines from overheating where the liner just drops causing catastrophic failures and some newer motor of moving liners from over heating or the block cracks behind the liner allowing coolant to get into the liners backing. The newer motors has an added shoulder preventing a dropped liner in an event of overheating or extreme temperature changes, but again shouldn't move without some heat stress or block failure. The block is aluminum and the liner steel they do expand differently but should not be an issue unless its in extremely cold or hot environment causing one to expand or contract faster than the other or factory flaw with cracked block causing the liner to slip.
The donor 4.6l i picked up already went 130k and going 16years and the liners did not move and I don't think it will move anytime soon.
For others looking for the 4.6 and swaps I would say relax. I used to worry so much reading the forums from so called internet experts or rumors, but after doing tons of researching and speaking to expert shops that build race car and Baja race trucks its not an issue unless overheated and most people are weekend warriors or never really push their motors like racers do.
Again the 4.6l already went 130k and going 16years and the liners did not move and I don't think it will move anytime soon, so pinning it and top hatting it won't be necessary. It feels good but its an expensive mod that is not needed.
Find a 4.6l, if it doesn't have a slip liner leave it, if it has one top hat it.
Also to test for the crack block use torque plates and pressurize the water system to check for cracks. Usually its obvious with a piston, valve steam cleaned from coolant entering the cylinder.
I also recommend those who are doing the swap to do a complete rebuild, so far I rebuilt 4 rover motors and none are well maintained. If you are going to go through the effort and time build a reliable engine that you know you build and would be babied and taken cared of.
The donor motor condition:
Simple way to tell is any sludge build up? Remove the valve cover and oil pan and look.
Next check the crank bearings, is copper showing through?
Is the cam shaft unevenly discolored on the lobes?
When rebuilding don't half **** it by leaving old parts in like worn rocker arms, lifters, can shaft etc. As they will create lots of metal particles ruining the new parts.
A secret to extended engine life is using magnet as filters that attaches to your oil filter. You'd be amazed the amount of metal particle it captures. I have powerful neo magnet by the oil drain plug and around the oil filter.
I'm glad this forum is more lively and responsive, been to a few that was completely dead and quiet. I'll try to answer as much question as I can. I'm by no means claim to be an expert, just learning more everyday. if I'm wrong correct me.
I do have some questions myself as this is the first swap I'm doing.
Can the 4.6l oil pan be reused? Vs. The 4.0 pan ?
Can the 4.6l front cover be used? Some claims the 4.0 front cover must be used instead of the 4.6. Why ?
I'm sure its possible figment issues but I haven't tried dropping in the 4.6 yet to know. Still in the process of machining the 4.6
Rock Crawling
Joined: Jun 2012
Posts: 436
Likes: 4
From: frisco texas
Between reading this thread, and my thread on the same topic, i've come to the conclusion that there is no right answer. basically the only way to do this is to pull it, and inspect your current block and go from there.
I was really just trying to get a shopping list together of all the possible parts i could need to make a bosch 4.0 into a bosch 4.6.
I was really just trying to get a shopping list together of all the possible parts i could need to make a bosch 4.0 into a bosch 4.6.
Recovery Vehicle
Joined: Dec 2012
Posts: 820
Likes: 230
From: Boston, MA
I dont know the person that wrote this but he seems to know what is talking about:
How to Power Tune Rover V-8 Engines: For Road and Track - Des Hammill - Google Books
Page 26 has the details of why you should not build a 4.0 block into a 4.6.
How to Power Tune Rover V-8 Engines: For Road and Track - Des Hammill - Google Books
Page 26 has the details of why you should not build a 4.0 block into a 4.6.
6th Gear
Joined: Nov 2013
Posts: 5
Likes: 0
Iv had my disco I for a year already shes quite cold then at normal operating temps the Ticking comes along. You know what!? no oil consumption.no coolant being lost. She drives like a dream. its an old design so I say its Okay.
