Thread: Pinning Liners in a 4.6

liners about about $100 each for just the parts

So its back to the 3.5l, thanks all..

Get your mate to contact Balmain Engineering. They appear to be the one who fits most top hat liners in Sydney.
Your mate can get them done at trade.

Scouse, he has the machinery to do it but just need to buy the liners ill call them and see if they sell them.

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I've read that before but not understood why. The 3.9/4.0 have the same bore as a 4.6. Why is the problem 4.6 related?

Changing from 3.5 to 4.6 is the cheapest performance upgrade one can do and, for most people, undetectable.

Originally Posted by p38arover

I've read that before but not understood why. The 3.9/4.0 have the same bore as a 4.6. Why is the problem 4.6 related?

Not sure of the specifics but it goes something like this.

The 4.0 and the 4.6 blocks are the same and when they were made they were given one of three grades (I think they used a colour dot system) - based on various tests (not sure exactly - but such as block hardness etc).

I guess, because of the higher capacity and performance of the 4.6 the highest grade blocks went into the 4.6 (I assume the High Comps). The middle grade could go into either the 4.6 or the 4.0 (I assume Hi Comp in the 4.0) and the lowest grade goes into the 4.0.

Now we seem to hear that there are more slipped liners in the 4.6 rather than the 4.0 but but that may not actually be the case - who knows. Looking at how the blocks are graded and used, you would think that more failures should be happening in the 4.0s but then in Australia the 4.6 has been around for a bit longer.

Garry

i get confused when this topic comes up. i've got a 4.6 in a disco and if my eyes don't deceive me i would say there is a step at the bottom of the cylinder wall which the bottom of the liner sits on. i know the motor was bought new to put into the vehicle.

so in this instance i can't see how a liner can slip. maybe the original factory motors didn't have this lip?

maybe it needs to be distinguished which type of motor is being talked about other than the cc?

I understood the problem to be that the liners were not pushed fully home when being installed and prior to the block deck being machined. The liner is then too short and, when the block is hot, can move down. I have previously posted a pic of a slipped liner.