Hi folks,

further to this thread -

http://www.locostbuilders.co.uk/viewthread.php?tid=159260

I finally managed to find time to take the cylinder head off suspecting a blown head gasket between 2 cylinders.

Unfortunately I found shrapnel melted to the top of one piston and the area around the valves - suspecting at first a piston ring had broken up.

This is the first time I've tried any engine work so I'm having to take things slowly - lifting the cylinder head with manifolds out of the engine bay on my own and 20 yards to the garage nearly killed me off though!

I called in for a new head gasket and the guy in the shop suggested the shrapnel could be "fingers" which heat up to atomise the fuel so after some research i found this on the landy forum.

"If it is necessary to remove the cylinder head,do NOT be tempted to have it skimmed.This should not,in any event,be necessary,since the head is a large and rigid iron casting,and not,to the writers knowledge,unduly given to warping. Skimming the head will(not may,but will) result in the aluminum"hot spots" recessed and pegged into the head falling out in service.When this occurs,the engine will be a write off.Head overhaul is a specialist job,and must be treated as such.This danger cannot be over emphasized"

It seems likely the damage is due to these "fingers".

Does anyone know if the above is correct - the engine is a write off? It started and ran reasonable on 3 cylinders before I took the head off.

How can I tell if the head has been skimmed or off before?

Is there any other reason why these fingers might fall into the cylinder?

if the engine isn't written off can I replace these fingers - best probably in all cylinders, then I can overhaul the valves, piston rings etc and rebuild.

Any advice, pointers to the right answers or people who could advise gratefully recieved.

thanks
Ian

have you emptied the oil out yet to see if there is metal particles in the oil? There’s usually a tiny quantity but lots would mean that metal has got into the bearings. I blew the head gasket on my last 2.25 petrol and had a slight distortion which was very successfully skimmed out. The diesel head very different. Take the head to a proper engine specialist and get it looked over, I’ve noticed in the past that overheated cast iron diesel head suffer from cracks.

Photo’s would be good

You'll find it easier to work on the engine if you take the left wing off, seriously it takes only 15 mins to do and then there is no reaching over the huge wings and everything becomes very easy, for a landy



[Edited on 23/7/12 by Mr Whippy]

I'll start by confessing to having no experience with landrover engines.

The term "hot spot" is not one I've ever come across before but google seems to suggest that it is a slang term for "pre combustion chamber"

Normally it is quite a simple job to change pre combustion chambers just use a punch through the injector hole to tap them out, remember to remove glow plug first. Put the new ones in the freezer and then knock them in with a mallet, they should be a couple of thou proud of the head when fitted new, this allows them to me compressed in to the head nice and tight

I've never heard of a pre combustion chamber failing in the manner described but it may well be a land rover specific problem. It's quite common for the pre combustion chambers to be cracked, if it's only a small crack and doesn't extend close to the edge or near where the head gasket seals then normally it's not a cause for concern. It's also quite common for the pre combustion chamber to be slack in the head, again it's not always a problem.

Do you have any pictures?

Cheers
Davie

I used to work for a company that skimmed cylinder heads and im sure we used to skim land rover heads with out any problems, as far as I can remember they are direct injection without pre combustion chambers and I cant believe the so called hot spots would be made from ally. Most engines with hot spots used hardened steel pre combustion chambers which can cause problems when skimming but the usual solution used to be to remove them and skim the head then skim the pre combustion chambers on a surface grinder to the correct fit.
Paul

Just realised it was only the newer LR diesels that didn't have the pre combustion chambers, the older engines did have and we would have skimmed these the same way as the peugots etc and removed the chambers before skimming and then adjusted the fit afterwards.
Paul

quote:

---

Originally posted by paulf
I used to work for a company that skimmed cylinder heads and im sure we used to skim land rover heads with out any problems, as far as I can remember they are direct injection without pre combustion chambers and I cant believe the so called hot spots would be made from ally. Most engines with hot spots used hardened steel pre combustion chambers which can cause problems when skimming but the usual solution used to be to remove them and skim the head then skim the pre combustion chambers on a surface grinder to the correct fit.
Paul

---

The 2.5 Landy Diesel (Pre 200TDI) had precombustion chambers and these are prone to work loose , or can even break up and fall into the cylinder.

I have a perfectly good 2.5 N/A diesel engine in my shed... Needs a new piston and a new head!
Usually heads that get a pre-combustion chamber work lose end up as scrap. Hence the 2.5 Diesel heads tend to be a tad expensive.

I dont see why, that if the precombustion chamber plug cannot be changed, although I would have it done ar a reputable engineering firm.
eg Turner Engineering. It might be worth getting a refurbished head.

LINKY

I did not think this was such a problem with the 2.25 diesel which is not as powerful, and agriculturally slower!

The Precombustion chamber is a cup shaped plug that sits in the head over the end of the injector.
There are little cast fingers that glow hot when the engine is running (These are NOT the glowplugs), and aid the burning of the diesel.
In the bottom of the cup is an oval (ish) hole into the main combustion chamber.

If you want a complete 2.5 NA diesel minus a head, U2U me. (I fitted a 200 Tdi when my combustion chamber cracked)

Just my 2d's worth.



PS... avoid the 2.5 Turbo engines made imediately before they started putting the 200Tdi engines in. They made them for about 3 years and were more trouble than they were worth. ie the 2.5 NAD engine was at its limits power wise. The 200Tdi was much better.

In fact why not jusy get a 200 or 300 Tdi engine and slap that in, well worth the effort.

thanks guys,

some really useful help here - I'll get some pictures hopefully this evening and post them up.

regards
Ian

For the cost a rebuild I would pick up a old 200tdi and throw that in, only problem may be the turbo which might hit the chassi leg. Other options would be the (4jb1) or the 3.1 Bighorn Engine..

Both can be fitted easily enough using a kit from Linky

...unfortunately, lots of experience.

Unsure what you mean by 'fingers', it's a big leap here, but I'll assume you mean the pre-combustion chambers. These are the little circular inserts in the head - which crack and eventually fall out. They can crack quite badly, but function and stay in the head, so cracks can usually be ignored.

It's the earlier SII heads that crack, between the valves. A well known cooling problem, sorted with the SIIA. Cracking in the head means a replacement is needed (in my experience and advice, worth nothing as usual).

Turner (or A.N. Other) will be able to assess/help/repair/replace your head, so speak to them. If your wallet isn't deep, then any head that looks OK (no cracks between the valves) will probably pull down OK.

....But, stop, grab a coffee and think....

New/refurbished/scrappie 200TDi's are a simple fit, the Montego (Prima) is a great engine choice but needs more 'fit'. The Transit 2.5 NA is an expensive fit (adapters), but the engines are a reliability legend.

I went for a Mazda (I've uploaded a photo) - don't know how to get it here, but it's
apparently. Lots of hassle fitting, but it's been a fantastic unit.

Anway, enjoy the 2.25, make sure the pump drive goes back in the right place/orientation (don't have a pint until you're sure!)

pictures added

there is a slight scoring in the cylinder block, I've not cleaned up the head yet but it does seem ok so far.

thanks
Ian


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Have you removed the glow plugs and injectors yet? If so were they whole? Is there any damage in either port behind the valves? Just thinking maybe a tip has fallen off or debris has been ingested. definatley something been rattling around in there.

Cheers
Davie

Hi Davie,

I took the injectors out and they seem fine, not the glow plugs yet. I've been trying to identify where the "fingers" would have entered the cylinder I think it must be the bottom slot in the last picture?

I've not taken out the valves yet either - this is my first venture into taking an engine apart and don't want to mess anything up - that said the shrapnel has made a pretty good job of that!

Are you aware of any similar companies to Turner operating in Scotland - they have a price of £395 plus VAT for reconditioning the head.

thanks
Ian

Any auto engineers will recondition your head, what do you get for £395? New valves, new guides, new valve seats, new PC chambers? If so then £395 seems like a good deal, all depends what is replaced and what isn't.

However given that it sounds like it will need bored due to cylinder damage you will be looking at a lot of money for new pistons/rings etc. Once you spend money on a re bore then it seems silly not check the bottom end over, so you may also be looking at a crank regrind and a set of shells.

If you go to the expense of a head overhaul, a rebore and a crank grind then you would be silly not to have the injectors overhauled also.

Reallisticly I'm guessing your engine is beyond economic repair unless you want to carry out the overhaul just for the experience.

Cheers
Dave

Thanks Dave I agree, you are right - it's all or nothing with the existing engine.

I think I'll have to decide on the following:

A fairly long re-build myself with specialist work paid for where needed.

A swap to a 200tdi or another series 3 engine permanently.

A 200tdi or series 3 temporarily and re-build the original to put back in at a later date.

As if i haven't got enough to do!

Cheers for your advice and the others above.

thanks
Ian

quote:

---

Originally posted by RedAvon
Hi Davie,



I've not taken out the valves yet either - this is my first venture into taking an engine apart and don't want to mess anything up - that said the shrapnel has made a pretty good job of that!

Is the exhaust valve in the picture seated properly in the head? Its difficult to tell from the picture but it looks as if it may have lost a valve seat insert which may be where the debris came from.
Paul

thanks
Ian

---

Hi Paul, thanks for the input.

This theory would explain the dint in the top of the cylinder head at about 1-2 o clock of the exhaust valve and the semi circular scratch between the two valves.

I've uploaded another photo and will try and get the valve out at the weekend.

regards
Ian



[Edited on 27/7/12 by RedAvon]

Paulf was spot on as per picture the valve seat has fallen into the combustion chamber.

I'm going to ask whether a local engineering company can put in new valve seats throughout - maybe new pre-combustion chambers and re-grind the valves.

I'll also need to get someone out to look at the slight scoring on the chamber sides and consider new rings and shells while the head is off.

A quick query however - when I pulled off the gasket I then started removing the remains and it looks like my least favourite material - ASBESTOS.

I guess this is probable if the head has never been off - difficult to tell - and the engine is 1983 ?

Any suggestions as to how to clean these remains off the head and block please?

Thanks
Ian