Thread: Pinning Liners in a 4.6

Pinning doesn't fix the leakage between the liner and the block.

Read this: http://robisonservice.blogspot.com.a...and-rover.html

Look at these videos: [ame]https://www.youtube.com/watch?v=R4odA3l2BAg[/ame]

[ame]https://www.youtube.com/watch?v=t-NrrCpHhP8&src_vid=C2EyvgxdyRY&feature=iv&annotatio n_id=annotation_234714[/ame]

[ame]https://www.youtube.com/watch?v=xx6_NZG18wY[/ame]

Thanks Ron do they only leak as a result of liner slippage? or is there another more sinister cause..

The block material can still break where the liners are pinned.

Lets see if I understand what you are wanting to do??

Use a 3.5 Block to fit a 4.6 crank or modify a 3.5 crank? You do appreciate that the mains journals are larger on the 4.6 and there is not enough room inside block for the 4.6 crank and it has to be ground in various places as well as the bearing casting line bored to take the crank etc.

However your post seems to indicate you are going to modifiy the 3.5 crank to give it a 4.6 stroke - there was a reason LR went to larger mains and made other mods such as cross bolted mains and thicker walled gudgeons.

What about cross bolted mains - a bit of machine work to get that done and the 3.5 block does not even have the reinforced pads in their lower block for the cross bolts.

Certainly can be done but starts to get expensive.

What are you doing about the liners - are you boring out the 3.5 liners to take the 4.0/4.6 pistons (can this even be done) - if relinering with 4.6 liners then go top hat.

What about conrods - 4.6 conrods are a different length and the gudgeon pins used in the 4.6 have a thicker wall material.

There are lots of things to consider, but of course anything is possible - but easier to get a dead 4.6 and rebuild - or a 4.0 if you can get a crank and conrods.

Garry

Originally Posted by garrycol

The block material can still break where the liners are pinned.

Lets see if I understand what you are wanting to do??

Use a 3.5 Block to fit a 4.6 crank or modify a 3.5 crank? You do appreciate that the mains journals are larger on the 4.6 and there is not enough room inside block for the 4.6 crank and it has to be ground in various places as well as the bearing casting line bored to take the crank etc.

However your post seems to indicate you are going to modifiy the 3.5 crank to give it a 4.6 stroke - there was a reason LR went to larger mains and made other mods such as cross bolted mains and thicker walled gudgeons.

What about cross bolted mains - a bit of machine work to get that done and the 3.5 block does not even have the reinforced pads in their lower block for the cross bolts.

Certainly can be done but starts to get expensive.

What are you doing about the liners - are you boring out the 3.5 liners to take the 4.0/4.6 pistons (can this even be done) - if relinering with 4.6 liners then go top hat.

What about conrods - 4.6 conrods are a different length and the gudgeon pins used in the 4.6 have a thicker wall material.

There are lots of things to consider, but of course anything is possible - but easier to get a dead 4.6 and rebuild - or a 4.0 if you can get a crank and conrods.

Garry

Garry,

No, I "was" going to rebuild a 3.5l motor, but now i have been offered a Complete 4.6l Short motor, everything minus heads, my mate said we should use this and freshen it up, hone rings, Bearings, ECT, then put my pair of heads off the 3.5l on it after doing some work on them, hence my question about pinning the 4.6l block instead of Top hatting it.

Originally Posted by Kevin B

....., hence my question about pinning the 4.6l block instead of Top hatting it.

Don't waste your time on a half job. My experience to date is that top hat liners is what these blocks need to be even half reliable. Unless you have documents proving the block is only 100,000km old and never ever did any towing, just put it aside until you can afford to do the job properly.

I have a job lined up this week to do similar things to a 1997 P38 HSE with a meticulously maintained 180,000km, it has a slipped liner and it'll be getting the lot done, once and for all.

Thanks bee utey,

i was afraid of that answer, but you don't know till you ask, i have no problem in getting liners fitted just buying them, ill do some research and see what there worth.

Ok - sorry - misunderstood. Thanks goodness - was worried about what I thought you were intending.

There are some old threads on here about pinning somewhere. As I mentioned the block casting where the pins would go is only about 1/4" thick or less and if the liner does try to move the piece of block casting could break way.

When you do the cam you will need to consider whether you are going with a dizzy or not. If a dizzy, you will need a dizzy cam and use your 3.5 timing gear cover (there are some mods required) - I think in this configuration a dual timing chain can be used. If you decide not dissy and use something like Megajolt to run the ignition then you use the 4.6 and timing gear cover but then you can only use a single timing gear chain.

You will also need to consider what injection you are going to use - I am not sure about the old flapper on the 3.5i but I think the 4CIUX off the 3.9 will work OK with some tweaks.

Again there are posts about this somewhere.

Cheers

Garry

im kind of thinking the cost/effort involved with a 4.6 conversion outweighs the cost of the vehicle, may just stick with my original plan to rebuilt one of the 3.5's i have here in the shed and just swap it over using all my current bolt ons, its gotta be a marked improvement over the tired engine that is in there now.