Bearings

mgme · Post by **mgme** » Thu Sep 20, 2012 7:56 pm

Evening All,
Caught the front bearing removing the camshaft (Range Rover with engine in). Small nicks you can catch your fingernail on. Is it ok to flat them off with 2000 grit or other ? Seems alright to me (will just store more oil in the nick)- wanted to check first?
Thanks hopefully.

ChrisJC · Post by **ChrisJC** » Thu Sep 20, 2012 8:45 pm

Should be fine. I believe one advantage of the soft bearing metal is that it will 'store' hard particles by 'giving' and preventing them from destroying the moving part too quickly.....

Chris.

mgme · Post by **mgme** » Thu Sep 20, 2012 9:13 pm

Thanks Chris. A relief to hear. I have a low compression problem hence the need to check camshaft. Compressions were low at the passenger bulkhead (120) and on the second cylinder from the front on the drivers side (155), have left them and the heads with some wd in to measure any loss. The drivers side piston is losing fluid gradually but dont think the pass bulkhead is -will check tommorrow am. Have straight edged the heads and block OK as are the gaskets. Its a never been apart 2000 4.6 V8 Bosch Range Rover engine. Got hot - think the stat stuck caused an air lock.

DaveEFI · Post by **DaveEFI** » Thu Sep 20, 2012 10:00 pm

I don't think the state of the camshaft would make any difference to cylinder pressure at cranking speeds. Unless it were preventing a valve from closing.

mgme · Post by **mgme** » Fri Sep 21, 2012 3:04 am

Thanks Dave, what am I/should I be doing?

DaveEFI · Post by **DaveEFI** » Fri Sep 21, 2012 8:07 am

Since you have the head(s) off, fill with paraffin and check for leaks past the valves overnight. You'd normally check the piston side with the engine complete by adding a small amount of oil to the low cylinder - this 'seals' the piston temporarily. I dunno a method of checking with the heads off other than by removing the piston and checking for ring etc wear, and would be interested of hearing of one.

mgme · Post by **mgme** » Fri Sep 21, 2012 8:41 am

Thanks Dave, Have left the heads soaking - they are OK. Filled the bores up with WD40 and left overnight. A mil or two loss from the 120 cylinder and half the fluid from the 155.

kiwicar · Post by **kiwicar** » Fri Sep 21, 2012 9:52 am

Hi
You don't really want WD40 in your engine, it is a rubbish lubricant and does nastys to the engine oil, can I surgest draining the oil before you turn it over and get the stuff in the oil galleries. Also when the oil is out thoproughly wipe down the bored with ATF (auto transmission fluid) it is full of detergents that should clear the WD40 out of the honeing and then put a little 2 stroke oil in each bore before turning over (mix it with petrol about 1:1 and use a plant spreyer)
er sorry but it really should not be in a working engine.
Best regards
Mike

mgme · Post by **mgme** » Fri Sep 21, 2012 11:39 am

Thanks Mike,
Have removed the WD40 and cleaned the bores. It is a block, pistons and crank (Used LR Rave manual). The sump is already off.
Would it be possible to not remove the pistons to restore compression?

sidecar · Post by **sidecar** » Fri Sep 21, 2012 3:18 pm

I would not use wet and dry on white metal bearings, the grit will come off and stick to the bearing. Just flatten off any raised ridges with a flat piece of steel like the back of a kitchen knife. Or don't even bother, they will just get knocked back by the cam journal.

mgme · Post by **mgme** » Fri Sep 21, 2012 4:21 pm

Thanks Sidecar.

mgme · Post by **mgme** » Sat Sep 22, 2012 10:08 am

Would it be OK to free the rings off in situ using carb cleaner/ boiling water? Would heating oil work / have enough bite? Are the conrod bolts re-useable? Sump is off.

Stu E · Post by **Stu E** » Sat Sep 22, 2012 12:01 pm

Had an emissions problem at SVA on a V6. The examiner suggested it was the rings stuck in their grooves and putting diesel down the plug holes and leaving overnight. Changed the oil and all was well.
Worth a try.
Stu

kiwicar · Post by **kiwicar** » Sun Sep 23, 2012 7:48 pm

Boiling water and strong detergent are good for removing gunked on old oil, fairy power spray is very good, but you do need to ensure it is washed off after and dried out after. Paraffin and diesel are pretty safe solvents in that they don't break down oil film in the quantities you get left as a residue, petrol is not so good as it does degrade oil except at very low levels, however a mix of petrol and 2 stroke oil are good as a surface cleaner if the petrol can evaporate and for a quick lubricant on starting a new engine. ATF is good for cleaning out honing grit out of a bore as it is full of detergents and tends to hold fine material to a paper towels and is obviously a good lubricant.
Best regards
Mike

mgme · Post by **mgme** » Sat Sep 29, 2012 12:17 pm

Afternoon All,
Went to fit the cam and found 5-6 mill slack between the final face of the camshaft and the thrust plate. The slack disappears when the cam sprocket is fitted, although, the Land Rover Rave manual suggests measure without the sprocket fitted. This is a Thor 4.6.
Any help greatly appreciated.