sako243 wrote:

What do you hope to achieve with "uprated" pistons? Forgive me but the standard ones are normally good for 100s of thousands of miles.

In fact I had two cranks snap on me this year, damage to the first engine: snapped crank, sheared three bearing block bolts and scored some bearings. Everything else fine.

Second crank drove from North Wales to South Wales towing 2 tonnes through the mountains. Damage: cranked crank...

So I think if the pistons survive crankshafts snapping I think they're probably good...

Blackhat90 wrote:

Ticking " i"ve heard cranks knocking and then go bang, usually sending a conrod thru the block, was yours just picking up on the man shells ? , ,snap is when the crank shears in two , these symptoms are caused by poor lubrication,

Not sure I understand what you mean by "picking up on the man shells", assume you mean main not man but still don't know what you mean by "picking up". Regardless I think I know that snapping means it's, well, snapped in two... I can assure you that it wasn't poor lubrication.

Crank #1

Click image to enlarge

You can see in the photo that it snapped on piston #4 which is at the back of the block. This particular crank left me without drive, fairly understandably. I'd not been 100% happy with the engine for a few weeks - there'd been a bit of a ticking noise which got better with a few things sorted. First the discovery whilst laning in North Wales I'd lost one of the long M8 bolts on the inlet / exhaust manifold. Subsequent examination showed I'd also got a leaky gasket which after preparing to fight all the studs and expecting some to shear (I prepared by buying the required bits and bobs, genuine from LR at great expense because I had to get in bulk, so have lots spare if people are interested). Anyway not a single one put up a fight and I replaced the gasket.

After that I still wasn't happy with it and then a few hundred miles later found a little bit of oil spray and the rivets on the vacuum pump had failed. So that got replaced with a new genuine part and things improved. But in my mind it still wasn't quite right - couldn't put my finger on it but I still felt there was a bit of a "ticking" / "plinking" noise somewhere but by this point I was almost convinced I was hearing things.

Anyway a couple of weeks and 1500 miles later after New Years I decided for the sake of an evening and £30 to whip off the head and have a look. Everything was absolutely fine, in fact could have probably reused the head gasket but I had a new one so put it on. In the process I'd dropped a bit of coolant into the block so thought, sod it might as well give it an oil change now and whilst I did that I took the sump off to check the bottom end, sod all play anywhere. Cleaned the sump out and hit it with the wire wheel and repainted it.

The following weekend was heading down to Wales and lost all drive on the Severn Bridge and that was the crank gone. Thought initially I'd run out of oil but the oil was so clean from having only done 150 miles that I didn't actually see it on the dipstick the first time I checked.

Anyway postmortem strip down of the engine revealed that the crank had snapped, along with two bolts holding in the big end bearing block between 3 and 4. Apart from that there was naff all damage - in fact the bearing shells could probably have been reused if absolutely necessary - I wouldn't have but shows how little damage occurred.

Crank #2

Click image to enlarge

It's not clear in the photo but that fracture / crack / snap is in-front of #1 piston. Basically at idle it was rocking back and forth and causing the knocking / ticking that I heard. When you accelerated slightly / put it under load then you were always driving against one edge of the crack so it wasn't rocking back and forth. It was only visible after I dropped the sump to have a look and even then took a little while to spot it.

In fact I suspect if was so inclined I could probably fire up engine #2 which is sat in the blacksmiths forge barn and it would drive OK albeit with a bit of a knock...

Only after crank #2 did I realise that the crank pulley was a harmonic balancer, it just hadn't crossed my mind. Now, in hindsight, it's obvious. Ed
82 Hotspur Sandringham 6x6
95 Defender 110 300Tdi