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Posted

Ok collective brains :P . The cheapo 300TDi engine I bought is now in a rather dirty pile of bits.

Water had got into the engine at some point and the pistons/bores took some soaking with WD40 before I could move it. After some cleaning it turns nice and smooth. The big-end shells were down to the copper on the top half, but still good on the lower half - something I've come across before on diesel engines, so i assume it's normal.

The main shells have a variety of wear patterns/funny marks on them and I can't figure out what was going on in there. The crank journals look perfect still to me, although I have only done a visual inspection at the minute. The bores have water stain/rust marks and vertical scoring as well - not sure just a cylinder hone would help here as there is no sign of cross-hatching anymore, so up to .020mm looks likely. The head has obvioulsy been skimmed, but there are clear signs that the gasket had blown between cylinder 2 and 3. The head gasket is a 3-notch (I'm pretty sure that 2-notch is standard) The deck of the block is also badly pitted between 2 and 3, so a skim there will have to be done. The head was definitely fitted badly - some of the bolts were crazy tight, whereas others were very easy to undo with a normal 1/2" ratchet. Anyway - engine porn for those of you that have stinky diesel preferences, and sensible comments please regarding rebuilding this engine.

Head - skimmed, but still blown.

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The deck - heavily corroded/pitted

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main shells. front of engine from the right.

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Main and then big end journals - all look the same as this.

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Bores 1 to 4

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Les.

Posted

I agree with Ralph - however, it seems a lot of work when you can buy a disco complete for £500, likely with a better engine.

Rebuilding is a lot greener though.

Si

Guest diesel_jim
Posted

I've got a 'zorst manifold gasket here if you want it Les.

Posted

Dosnt look toobad to me. Give the bores a good honing, new set of piston rings and big end and main shells maybe.

Skim the head and pop it back together.

Seen worse and made them run well.

Dont worry too much about the thickness of the headgaskit its all to do with compresion and skiming the head wont effect that as the cobustion chambers are in the pistons.

Posted

I'm kind of with Si on this one, you'll find a good disco for silly money these days....

however, as you can do most, if not all of it yourself, and the parts etc are not going to be horrifically expensive then go for it, even if you plough £400-£500 into it at least you know you've got a sound and strong motor with no hidden secrets...

Posted

Doesn't look too bad, but i'd hope it was very cheap.

Have you put a straight edge across the the head, it could be bent beyond recovery, the scoreing in the bores looks like the pistons have got a bit hot and swelled up at some point.

To be honest i'd be binning it and finding one that need less block work.

Posted

Les far less damage than mine and that has been re bored/skimmed and is ready to go again for less than £400 for a nearly good as new engine.

IIRC Les paid a very good price so a rebuild should make this a cheap engine.

Posted

Les

+20hou are the largest over size pistons bearmach do cost around £50 apiece

I got all the parts from exeter4x4 AKA Bearmach so you should be able to get a good price

Posted

Trouble is with a £500 disco engine you end up with a bottom end at least that is in no better nick than that one.

I'd be inclined to shove a set of standard sized shells in it, hone the bores and see what they come up like, shove a set of rings in it and deck the block and skim the head again and put it all back together. IMHO those bores dont look too bad (ok its hard to judge from the photos) and would probably clean up with a hone.

Jon

Posted

When these overheat badly (from loss of coolant), the hardness of the alloy head is affected, and can result in some head bolts not retaining their pre-tension.

This would be consistent with some of what you have described.

Regarding the head gasket thickness (number of notches), this is determined from how far the piston crown extends above the deck of the block.

Posted
Regarding the head gasket thickness (number of notches), this is determined from how far the piston crown extends above the deck of the block.

Yes I know - the deck is being skimmed.

Les.

Posted

Can't remember the exact figure, but from memory if the head has warped more than 20thou it is a binable offense.

Check with Richard at Turner Eng.

Jim

Posted

20 thou rebore ………………….. 10/10 regrind on the crank …………. Also it may pay to have the cam bearings replaced……………. Even if the head is scrap, they are relatively easy to come by s/h…………….

Spend a bit of time and I guess about £500 / £750 on this engine and at least you know what you have got …………………a moon mileage s/h lump will cost you the same amount of money but will be an unknown quantity ……………

If you do decide to do the rebuild (and I think you should) pm me and I will give you the name of the guys that did my liners ………….. top quality work at very reasonable prices.

:)

Ian

Posted

According to the Genywine Land Rover manual, you can't skim the head at all. You can just add that to the list of things the manual says you mustn't do and we all do. :P

It is not too unusual for the head bolts to settle, sometimes causing the gasket to blow. In my case, at a couple of years old (the engine, that is ) I noticed a water leak under the air filter housing. The two bolts that hold the air filter bracket on were both finger tight. I just tightened them up and it has been ok ever since.

I would have thought that rule 1 of cylinder head clamping is NOT to use the head bolts for any other purpose, even if you can save the accountants a couple of pence by doing so.

Posted

If the head isn't straight then it is probably too soft as well, so even if you can skim it failure in that area will occur again.

Greater wear on the upper shells of the big ends and the lower shells of the main bearing is as you say normal,on petrol engines too, as that is where the higher loads upon ignition are applied.

Bill.

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