Thread: 3.5 litre cylinder

Originally Posted by RoverP6B

If a liner is going to move, the time when the noise will be most noticable is when the engine is cold and first started. Once up to temperature, the block expansion will hold the liner still and the noise will no longer be evident.

The aluminium block expands at a faster rate than the iron cylinders so it loosens off the liner when hot, not the other way around.

I don't think the 3.5 is prone to having loose cylinders as the block is a lot thicker in the walls than the 3.9/4.0/4.6.

Yes AFAIK the tension of the sleeve is lost usually when the block cracks behind it. That is why water comes out.

The 3.5 does not have such a problem as the block is thicker behind the sleeves.

It has also been proposed that the stretch bolts used on 4.0 and 4.6 put much more tension on the block and may contribute to the problem.

Regards Philip A

I have heard of 3.5's in early P6B's slipping liners, not common though but has been known to happen, AFAIR they were Hi comp engines, 9.25:1 and 10.25:1.

I have never had or seen a low comp 8.13:1 3.5 do this.

JC

Hate to be the bearer of bad news. I have 3.5 and on two occasions have liners work loose. currently have to decide what to do as the last rebuild was only 70,000km ago. Liners don't move when cold by the way, only after some 10-15km to full temp. I spent zillions on temp control; radiators, water pump,electric fans after the last rebuild. Engine runs at 80-85degC, below 80 the liner doesn't move. And yes, they do move up and down, hence the quite loud banging that occurs! I don't tow anything either. If I get this re-built I will get top hat liners installed!