Engine rebuilding

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vanny
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Engine rebuilding

Post by vanny »

My god it's quiet in here!
Well this should liven things up!
I'm about to start rebuilding my poorly sick 1.9TD engine, and to be honest i've not done anything like it before!
To put it into context i have the head in the kitchen and the bottom end in the garage (20 miles away). I'm happy that i need to take the head to bits to check the valve guides (current best reason for smoking following a bent valve), though i have no real idea what im checking them for! I can get the valves out but thats about it!
<i>1) How do i check the valve guides and or get them out?</i>
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At the same time i figure i might as well replace the valve stem oil seals (think this engine has them and i think there green with metal bits?)
<i>2) How do i replace them valve stem seals (removal/refitting)</i>
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I Figure im gonna pull the injectors out so i can properly clean the block with everything out! I know they have fire seals and various other bits, is it worth replacing these at the same time? I would consider having them reconned but it seems a bit pricey at £40 per injector and they only have around 70k on them!
<i>3) Is there a special tool to get the buggers out? How do i replace the fire washers if needed? What should i look for when lifting the injectors (cracks, scoring etc)</i>
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From what i have read the swirl chambers are prone to cracking on the XUD heads so i guess i'm best to check these? As of yet the head has not failed so i dont anticipate it being warped, i have considered taking it to a local specialist (who so far has been excellent) to let him cast an eye on it. Before i do that is it worth being a tool and measuring the head to see if it is warped? Is there anyway to check for cracks? I have magic dye that i could coat the bottom surface with then wipe off and scan with black light to see if there is soak into cracks. As i understand it this is exactly how heads are crack tested, does that sound about right?
<i>4)What should i look for when visably checking the head? How does one go about measuring the warp (if any) of the head?</i>
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I would like to get to doing some work on the ineards of the head. I specifically want to grind/lap the valves in propely. I understand how to grind them in, but what is lapping and how is it done? I have a rather informative book on how to basically reengineer the inlet and outlet ports to increase fuel flow etc and i will attempt some small refinements. What is the best way to 'polish' the ports? I'm guessing i dont want to go to ASDA and get some furniature polish?
<i>5)What is lapping? Any tips of grinding valves in? How should i polish the ports?</i>
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And finally (for now) i want to make sure i get as much of this head rebuild as feasible and i want it to be maticulously clean as well. I'm happy with petrol/degreeser and a tooth brush but is there anything i should watch out for or focus my efforts on? Is there anyway to 'wax' the head to stop external dirt build up, or would it be worth me polishing the whole of the outside up so its smooth as ice and dirt dont stick?
<i>6)What areas do i want to focus on cleaning and how do i stop dirt simply getting on the outside again?</i>
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The head rebuilding is going to take place in the girlfriends kitchen (ha she's away this weekend as well) it's a lino floor, i have a tarp to go over the top of it and i have plenty of news paper, but when i do track dirt all over the house how do i clear it/hide it?
Next weekend her parents are visiting, and im sure they wont be too impressed with an engine rebuild taking place in the kitchen! Any cool tips on how/where to hide things? I cant get access to the loft or it would all go in there!
Any other hints and tips muchly appreciated! I will be keeping everyone upto date on progress in another thread (including pictures!) and i guess i would eventually turn the whole thing into a bit of a step by step guide so i'll take ANY comments!
Stinkwheel
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Post by Stinkwheel »

Blimey, dont want much do you vanny :-)
right, these are my understandings of the questions you have asked........
1. Valve guides should be checkable by eye and feel when you have the valve out, look at them, any visible wear spots? hold the head of the valve and 'feel' for lateral play, any more than nough to allow the valve to slide into the guide is too much.
2.Valve stem seals, you are right in your descrription of them. Grab the old ones with what you can (pliers) and twist/pull them off. Installing new ones, find a small socket or similar that fits nicely round the outside top edge, if you see what i mean, and tap them into place. This is the home mechanics way of doing it, order a couple of spares, you will knacker a couple if its firt try.
3.NO idea.
4.Forget about it, take the head to your local head specialist. For about 50 quid he will check it all, warpage, cracks (pressure test) and pronounce fit or not, he will even usually supply you with head bolts and gaskets at reasonable prices off the shelf.
5.lapping and grinding, same thing different terminology. Coarse paste first then lighter grade for final seating.
6.If you can get it ultra sonic cleaned this will brong it back to nice and new virtually, and will stay clean afterwards with regular washing down.
Hope that helps, again, only my views. if im glaringly wrong please someone point it out.
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Post by dnsey »

Motor Factors and decent tool shops sell sockets for removing injectors - as usual, they come in cheap (use once and throw away) and expensive (lifetime investment) versions.
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Post by fastandfurryous »

for q.(1)
the best way to check the guides is with a brand new valve. Put it in the guide, and wiggle it side to side. If the head of the valve moves more than about 0.5mm side to side, then the guide is biggered. Hope that they are all OK, as new ones have to be pressed into the head while the head is heated, and then reamed in position. I had them all done on my 405 TD engine: The valve guides were £6.50 each. The total bill was nearly £200 once the labour was on, and that was a "for cash, mate" deal, doing me a favour.
for q.(3)
The fire seal washers should be changed along with the copper sealing washer that comes out when you take the injector out (27mm deep socket) They lift out easily, and are pence. They're included with a head set (which would be well worth getting). Make sure you put them in with the convex side facing up. Some engines have been known to have them fitted incorrectly from new, resulting in horrid injector wear (more on that below). There is also a sleeve that sits under the injector, which is about 15mm diameter, with a smaller hole in one end. Worth taking these out and cleaning them.
To inspect the condition of the injectors really needs a visual tester, which is basically a hand diesel pump and a lamp which shows the spray. Alternatively, you can just look at the end of the injector. The business end should be flat, and you should just be able to see/feel the end of the pintle needle poking out in the middle. If there is a "worn" recess, about 5mm diameter in the end of the injector, then it's worth having them reconditioned (should be no more than £20 per injector. £40 is a rip-off) Don't be afraid to wire brush the end to see what's going on. My local injection specialist puts them on a power wire brush to clean them.
for q.(4)
Cracked swirl chambers are a fact of life with an XUD. They crack after about 10k miles from new, and remain cracked until 300k miles. Your best bet is to not worry about warpage, craked swirl chambers, or any other test, and just have the head skimmed. Far cheaper, and it guarantees that you get a decent seal on your new head gasket. I now always have a head skimmed if its off. The test you've described is a dye-pen test, and will show up all sorts of surface anomilies. If you get it skimmed, you know it's perfect.
For q.(6)
The best way to keep a head clean is to change the cam cover gasket. These go rock hard from oil damage, and leak for a pastime. If you can keep oil off the head, then it will stay clean and (possibly) shiney. If you get a head set, you'll get the fire seal washers from above, valve stem seals (the socket is definitely the best way to go with them) a cam cover gasket, camshaft oil seals etc.etc.etc....
for q.(5)
forget it. The intake of the XUD engine is very good indeed, and there are some theories out there that having a slightly rough finish on the surface of the ports increases surface turbulence, which is better than having it perfectly smooth, and having a larger area of lamellar flow. All a load of bollocks on an XUDturbo engine anyway, as increasing the boost by 0.05psi will do far more than any work you can do on the (already very good) XUD head.
As for hiding bits around the house, an XUD head fits surprisingly well into a large shoe box, which then looks very innocent on top of a wardrobe! [:D]
Hope this is of some help.
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Post by madasafish »

Do not hide engine parts on any raised surface. Lifting them up and down is hard work!, Craefully cover in cardboard, neatly wrapped with some tape as if it is a parcel to be posted and hide in a forgotten corner..
Seriously, lifting heavy weights near head height can be dangerous. If you try to move them when your muscles (or back) is stiff, cold or otherwise unresponsive you can pull muscles, or even worse - damage a disk in your back. And near head height you have little control when things go wrong.
(I smashed a toe following an incident with a Triumph 2.5PI crankshaft. I could walk again after days:-(
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Post by James.UK »

Vanny. By the time you have got your motor up to scratch it may well have cost you a lot of money as well as time.. [V] But.. [8)]
I noticed that Stewart, (oilyspanner) has a couple of decent looking engines sat in his garage, as he is pretty local to you, it's well worth asking if he will part with one. [:)]
.
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Post by tomsheppard »

Bet you are glad it wasn't the 2.5 gearbox!
vanny
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Post by vanny »

James that may well be true but by the same aspect i've wasted a good 200 quid on an engine that doesn't go, and his one cost me a good long month of hard graft. I know what the problem is with the 1.9td, and not only that i know what the cause was as well. Infact i know a desirable chunk about the history so as far as im concerned its worth the £200 investment to make sure the damn thing is perfect and isn't gonna have to come out again next year!
It's pretty simple, if the engine comes out again before December 2006 then the car is going to be scrapped and i'll be off to by something meaning less like a 205! I have by no means had any sort of beneficial 'luck' with the BX's, and while i've sunk a lot of love into the current one, i've also sunk myself into a lot of debt in the process! This is the final all or nothing jump into the abis!
Another replacement engine simply isn't worth the hassle, nor another god knows how much to have it blow up in my face, this is very much a case of better the devil you know!
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Post by jeremy »

If I'd got the engine out I'd be looking to do all the bits that are difficult or impossible with the thing in the car. If I recall correctly this engine has a history of smoking and running badly on one cylinder so I'd have a good look at the bores and pull the pistons out, and at the very least fit new rings. At the same time I'd replace the shell bearings on both big ends and mains (ideally getting the crank measure before buying.) I'd also check the oil pump drive chain and the pump itself - which is of course an extremely high capacity one on a Td.
When I'd finished I'd be confident that I'd got an engine that was 100% sound and could take loads of hard use and even a touch more boost. It would of course need to be run in very carefully.
I'd suggest that valve guides are not very important on these engines - petrol ones can allow air past them which will intefere with the mixture.
jeremy
vanny
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Post by vanny »

Jeremy the belief is that the busted valve guide or valve seal is the problem with the engine and the cause of the smoke! However i should know more in an hour or two!
vanny
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Post by vanny »

Latest Update
Pictures can be found here ;
http://www.bxproject.co.uk/gallery/jazz ... 202005.htm
Have first four valves out and have partly cleanded the head mating surface. Initial observations, well its pretty damn clean which is nice! would seem the first outlet valve (bigger one) is the one not correctly seated/ground in. Original suggestion that the valve guide was damaged seems inaccurate! There is the same play in each of the first 4 valves, but two of the valve stem seals look a little battered.
Gonna try and ge tthe seals out in one piece but thus far i cant see any real problems with it!
Image
this is the worst of all the pre combustion chambers, the 'big' crack is actually mostly a slither of oil and the crack isnt as bad as it looks!
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Post by Dave Bamber »

Those cracks are no worse than I found on mine, no problem!
jeremy
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Post by jeremy »

Well done Vanny - its coming along nicely.
From having spent too long haunting discussion boards and general interest in Citroens camshaft wear doesn't seem much of a problem. generally when these things wear its quite apparent as its the tips of the cams that go and the surface no longer looks smooth but resembles concrete. Not a good engineering description but when you see one you will know what I mean!
A defective valve (seating) will I suppose produce copious smoke on a diesel, particularily at idle as there will be insufficient compression to ignite the fuel properly and so atomised but unburnt fuel will be dumped into the exhaust - if its that valve that has gone. The engine will also feel lumpy, underpowered and rough.
You will need a new valve and will probably ghave to get the seat cut with a proper tool as the metal will be so xxxxing hard that you will never gring the pits out. best to start grinding the others as well to see if they are going to come up nicely (they probbaly won't)
Cracking - don't know what is considered permissible on the pre-combustion chambers but would have thought you've probably got some more life in this head. The area of more concern is the valve area - many heads crack between the valves (all makes). Sometimes they can be salvaged by new valve seats - ran a BMC 2.2 for some years like this with a low temp thermostat!
The head can be checked for straightness reasonably well by cleaning it thoroughly and looking along it - or using a (really straight) straightedge. The usual difficulty is getting all the old gasket and muck off it without damaging it and I've been known to use a carpenters oilstone (for sharpening chisels) to gently abrade the surface without taking anything significant off. (I also in desperation painted a new gasket for my Hillman Hunter with silver paint in a desparate attempt to get a banana shaped head to seal - yes it worked!)
A thin skim is however ideal as it will give a really clean face and make a better seal. You can probably get thatdone at the same time as the valve seat cutting and you may find that the engine specialist can supply valves at reasonable prices.
Enjoy your Sunday!
jeremy
vanny
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Post by vanny »

So far not enjoying my sunday, though that is down to last nights activities rather than anything car related!
Getting the head surface clean is a nice easy job when you have the right tools! Razor bladed gasket scrapper and a tooth brush and some of Total's finest petrol and the whole thing scrubs up quite well. Did all that yesterday when hosed the bastard head down in the yard, only one way to dry it, in the oven! Have some brilliant pictures!
Im desperately trying to avoid skimming the head since it's never been done on this head and i have NO reason to believe that it is any way warped, it's not been over temp or anything yet, just a little bit smokey! My theory is that i might stick a thicker gasket in, drop the compression ratio slightly allowing for more increase in the boost.
However having taken all the valves out i was starting to wonder where the fault was, until i got to the last valve! Bloody thing near didnt come out. Found it was sticking on the seal, then after that had been ripped off it was still sticking in a couple of places and had NO play when fully inserted. The others all have some play in them! sticking the valve in another whole and it seems pretty much okay, and sticking another valve in the hole and it is still sticking (all be it a little less), so my suspicion is that the valve guide is some how buggered and i'll look into getting it swapped and getting a new valve in it.
On the grinding in aspect of things, just how is it best done? i appreciate the valves will be hardened, but surely the head alloy is soft enough to be ground out? I was thinking i might just attach the valve to a drill, lob some paste on it and off i go at a low speed!
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Post by Stinkwheel »

do it by hand with a stick with suction cups on. Yuo will be having a new valve guide in so the specialist will cut the face into this as part of the service. Whay are you avoding having the head skimmed? If its going to the specialist anyway it will save you a lot of hassle later if it turns out to be a tiny little bit warped.
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