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hi all,
This is an update on my journey into the bowels of my GEM 4.6 Range Rover engine rebuild.
Some might recall my previous post of some days ago when I was debating whether to strip the Rangey down or leave well alone. The car was going fine but the oil light flickered on at idle and it was consuming a little oil and certainly the oil was going black prematurel.
Well, I launched into it, not a pleasant task. As often happens it is the little things that cause the most grief. Particularly getting apart some of the multi-pin plugs, draining the fluids but still living with coolant everywhere but worst of all is the hideous heat shield surrounding the exhaust manifold. No way were the tiny nuts and bolts undoing, everyone of them sheared off, I ended up virtually destroying the heat shields.
I couldn’t believe how filthy the engine is once I removed most of the ancillaries. Dirt makes motors so much harder to work on.
Once I got down to the valley I was surprised that the cam and tappets appeared to be in perfect condition, particularly as i thought the vehicle was a bit down on power an the lower revs band.
On removing the sump I realised someone has been in there before me with large amount of silicon in place of the gasket.
The heads came off easily and generally looked in excellent condition.
The bores appear very good with no lip or scoring. They look very glazed with little visible honing marks.
The big end journals are in good condition but the bearing are totally back to the copper.
The pistons look good with no broken rings etc.
The rings are in intact and don’t show undue wear.
reaching a finger into the timing case the chain feels rather slack
I will obviously replace rings and bearings (hone) and have the heads reconditioned but what else should I do?

Questions!
Im really surprised, I cannot find any numbering or marking on the pistons, rods or caps indicating piston number, direction of installation or what cap installs on what rod. I can’t even find stamping to tell me that the bores or bigends are standard size. Fortunately I marked the pistons and caps before I removed them. How does one tell which cap goes on which rod and which piston into which cylinder.
A complete kit (minus pistons ) is available from the UK in eBay but it includes a cam and tappets. Should I bite the bullet and replace the cam?
Should I replace the rod bolts and the head bolts?
Is the heat shields on the manifolds necessary?
Should I replace the oil pump components?
Is there anything else I should be looking at?
Who is the best parts supplier in Australi?

Any assistance or advice is greatly appreciated .
Al
 

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1995-2002 Range Rover P38A
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hi Alan to answer some of your questions , no markings is a good sign as it says it hasn't been over sized but you will have some machine work to do . with the bearing wear i would advise you have your crank measured for size also if your bores having shiny spots, tells me they are oval and will most likely need oversizing when you marked your rods i hope it was in relation to the firing order as that makes it easier to put them back where they came from, usually you mark both rod and cap as one so not to mix up . the head bolts are stretch type and will need to be replaced not sure on the rod bolts , yes buy a new oil pump , also consider replacing the cam lifters and timing chain and top and bottom sprocket usually comes as a kit . would also recommend having heads serviced , valves and seats machined, guides checked and replaced . if you need to rebore ask about having your cam bearings replaced at the same time as this is a machine shop job. hope that helps you in the right direction , good luck with it , take your time and remember to keep it clean.
 

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Alan, you might find this document of help, it is the specific engine overhaul manual and much more detailed than the workshop manual. The pistons and rods go one way only as the gudgeon pins are slightly offset. You should have markings on the piston crowns if you give them a good clean.

The bearings should have a stamp on the backs saying STD or 010 etc depending if they are standard or undersize. If the is no stamp, then it is safe to assume they are standard.

Replace the oil pump seeing as you are that far in and you feel you had low oil pressure to begin with.

Don't waste your time with replacing the heat shields. The only caveat here is to wrap some heat reflecting material around the two knock sensors as manifold heat will eventually destroy the plug connection.

Replacing the cam and lifters on an engine of this age might be a good idea. It will depend on your budget, but worth doing.

As for local parts, I have had good service and good prices from:
T R Spares in Sydney
British Motor Imports
And british4wd land rover parts hobart
 

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Measuring the bores is not optional and easy to do. Measure the cylinders and see how oval they are. If you have shiny spots and crosshatching gone, you probably need a re-bore and a hone. On high mileage engines it is almost always the case.

Engine rebuild decisions are based on measurements. Everything else is unacceptable guesswork and substandard repair in my opinion. Rover v8 parts are not very expensive. Boring the cylinder is $20 per hole in my area. You will need to hone anyway, so you are paying for that regardless. Might as well re-bore, fit new pistons and do it right.
 
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