Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1431
My 2.7 Engine Autopsy
Ok, after dismantling most of the engine i got to the crankshaft to find out what had gone wrong and my options going forward.
Taking off the sump with bated breath found thin strips of i assumed bearing material that had been hammered by the conrod and slipped out.
No.4 big end journal had been totally trashed and was running metal to metal.
The adjacent Main journal (No.3 Mains) to No.4 big end showed that the bearing had spun as the upper bearing half with the hole for the oil distribution was on the other side as i lifted the bearing cap.
There were some very very minor scratches to the bearing outer surface which meant that the bearing had not spun much and there was no overheating marks on the bearing or the cap. This may have been because the engine was swithed off fairly swiftly, or that the bearing had spun a little in the housing enough to block the oilway which had starved the bigend to the adjacent Main bearing.
Conversely, the No.4 big end may have failed first which restricted the oil pressure to No.3 Main bearing.
I dont know how the oil is distributed through the block and then through the crank to the bearings.
It is now a question to see if the block is useable as the spunbearing may have enlarged the housing although having had a look at it, it may be ok as i can still see the original machining marks (a bit like the honing marks in the cylinder bore) on the bearing cap - and no i am not misconstruing the machining marks for the spunbearing marks as the maching marks rather suprisingly are at an angle to the rotation of the engine. - again similar to the crosshatching of honing marks.
As the bearing material is softer than the block, it may still be to tolerance.
I will now take the block to my man at an engineering workshop and ask him to measure No.3 mains against the other Mains to check any difference. The other 3 Main bearins seem to have been unaffected and the bearings were in their correct respective halves as i removed the caps.
If the block is usable, i will be looking out for a conrod.
If not i'm on the lookout for a S-type jag
17th Jan 2016 5:38 am
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Pictures to follow?Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1431
Crankshaft with damaged conrod journal.
Click image to enlarge
Mains Bearing No.3
Click image to enlarge
Click image to enlarge
Yes that is a 8 foot long 2inch square section bar i had to use. Used a 3/4 inch airgun and that would not budge it either so had to resort to this
19th Jan 2016 1:22 am
garrycol
Member Since: 06 Dec 2010
Location: Canberra
Posts: 1117
I wonder that as the engine gets older and the bearing shells wear a bit there is then enough room for the shells to move and spin.
Is this problem age related or can it happen at any stage in the life of an engine.
Garry
19th Jan 2016 2:58 am
defector
Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1431
I think this has occured at various mileages.
Its hard to speculate if it is lubrication related or other mechanical reasons.
I know on some other engines, spun bearings are related to overheating of the engine at some stage.
I must admit the bearing width seems small compared to other engines i have seen.
19th Jan 2016 9:32 pm
defector
Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1431
Good news, the mains Bearing carrier -No.3 - that had spun the bearing was measured by the engineering shop and was the same as the other three.
So i will hopefully be rebuilding the engine.
I now need to get a crankshaft and bearings and one conrod - Bearmach conrod going for £25 via one of the suppliers, anybody have a view on Bearmach engine parts?
22nd Jan 2016 3:38 pm
lynalldiscovery
Member Since: 22 Dec 2009
Location: Maidstone
Posts: 7274
Something that critical I would pay the extra and get oe.
22nd Jan 2016 6:52 pm
Kingmav66
Member Since: 20 Jul 2010
Location: Gloucestershire
Posts: 1349
defector wrote:
anybody have a view on Bearmach engine parts?
Put it this way, if they sold toilet paper, you would have under your nails. Of course, that's just my opinion.
22nd Jan 2016 7:12 pm
defector
Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1431
Yes, i wasn't sure as i haven't really much experience of Bearmach or their products.
23rd Jan 2016 2:33 am
Disco_Mikey
Member Since: 29 May 2007
Location: Dundee, Scotland
Posts: 20764
The only issue I have had of anything supplied by Bearmach was the oil pumps. Rest of it has been good My D3 Build Thread
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
under your nails. Of course, that's just my opinion. 
