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Favorit - Removing cylinder head bolts


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If it helps, when I changed the cylinder head gasket on my car I bought a complete set of new head bolts from Wilco Motor Spares for about £50.  I don't know if they have a branch near you, but they didn't have any trouble sourcing the bolts. 

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I've 'mounted' a head gasket in Photoshop to see what more needs to be done. As you can see, there are a few coolant passages that need drilling and deburring for smooth flow. Although not being perfectly repaired (yet good enough given previous corrosion) the head will hold for many years if torqued by the book and using new bolts.

 

Take care on mounting the head gasket with the correct face up. The oil passage (shown to the left - copper ring) must be free.

 

8fjlzG4.jpg

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The sorry tale so far:

 

1.   The obstructed water holes in the head.  This one worried me a bit. I didn't like the look of the obstructions, and Ricardo confirmed that. But how to safely open them out? I haven’t got a vertical drill or mill, so I had to do it freehand. My concern was that one slip and the nicely honed head face would be ruined. I decided to use a conical rotary file / rasp in a portable drill. Firstly I thoroughly cleaned the surface of the head. Then I lightly held the new gasket (correct way up) onto the gasket surface and marked the area needing removal with a felt tip pen. I clamped the conical bit into the chuck of a lightweight battery powered drill / screwdriver and wacked the torque right down so that if the bit jammed it would not cam out. I dipped the rasp regularly in white spirit (very similar to mineral spirits in the US I believe Ricardo) to prevent the ally picking up into the teeth of the rasp, and patience. Lastly I blew out the head with an air line, including the oilway. Incredible amount of swarf in the head

 

2.   The Bolts. When I collected the 2 filters yesterday that I had ordered two filters I had ordered online from GSF Car Parts just down the road from me (just after they closed for the holiday - GRRR) I enquired whether they did head bolts. No, but they could get them for me by 11 am today. They arrived about an hour late. Victor Reinz, 14-32167-01 rattling about loose in a sealed box. I opened them to check, didn't quite like the look of them, and the found I had 4 long bolts and 5 medium bolts. Sizes looked ok, although I didn't check the threads. I took a refund, which hurt, as GSF only charged me £18 for them including the vat. The VH website is pretty unhelpful, but fleabay suggests that contents were correct, but the bolts were for a Fabia. Perhaps it's as well as it appears they have a reputation for supplying BENT bolts. Anyone any experience of VR?

 

I have sourced an alternative from ebay - BGA BK6362 at £35.

 

3.    The seals. Ricardo will probably kill me for saying this, but I'm desperate to get this thing back on the road - I need it for work - and when I thought I could get a set of bolts sharpish I had decided to live with the old seals. The guy who did the head reckoned there were ok, and I was prepared to trust him. It's not as though they would cause a catastrophic failure. I had sourced on fleabay a set for £12.44! BGA VK6338. 8mm seals as per my head. There appear to be 7 mm options around as well so I checked the manufacturer's part number.

 

4.    Regarding British Gaskets Group, aka BGA, website seems professional, good deal of technical info, anyone had any experience of their parts?

 

5.    The old bolts. The old ones were marked 10k.  The 2 I bought new from Skoda were marked 10.9 I've done some research and it seems that 10k is the old DIN standard and 10.9 is the new IEC standard. I haven't got access to either standard but I understand that they are effectively equivalent.

 

I've tried to get a better idea of the stretch. I've decided to try to measure the top 40 mm of the thread of bolts which has stretched with vernier calipers.. The bottom 27 mm or that screws into the head seems unstretched. so in The only bolt I've measured is the pitted one Recardo posted the photo of, which seems to be one of the worst. It's quite difficult to get an accurate measurement as the points of my callipers don't quite get to the bottom of the threads, but taking several measurements, the stretch over 40 mm seems to be about 0.3 mm. Out of interest I want to get some comparison between bolts. I presume that there will be some manufacturing tolerance between individual bolts and that comparison of overall length would not be useful, but I will do it anyway as measurement will be easy with a feeler gauge.

 

It's a shame I did not do this when I did the head last time, but I was completely ignorant of torque to yield then. I've reused these bolts once, so assuming OEM and noone else has had the head off, that will be twice so far. I say that because, although I'm pretty sure my father in law has had no trouble, someone's put a radiator fan thermostat override switch switch under the dash, and I've always wondered why. I've never had problems with overheating.

 

The main reason is that I want to get the best record I can of what has gone on, and to get a fuller understanding of the implications of angle tightening bolts, but in the back of my mind is a mean little thought that if I have further trouble sourcing a decent set of bolts, just how risky would it be to use this set again.

 

Given that there is differential expansion between the block/head and the bolts, the greatest tension would be with the engine hot. The exact coefficients of expansion would depend on the actual alloys of steel and aluminium (where's a metallurgist when you need one?) but If my arithmetic is right, using ballpark figures I get something like 10 thou between 32 deg F and 212 deg F (I took my coefficients from a US website) ie about .25mm between 0 deg C and 100 deg C. (It's been frosty and foggy here for the last couple of days.) I'll need to check the figures. All this suggests to me that even if a bolt doesn't snap when it's tightened it just might when the engine gets hot. Does this alloy get significantly more brittle when the temperature drops I wonder? Wondering because I have no idea what the temperatures here are going to do over the next week or so. Mind you, I'm likely to wait until it's at least 5 deg before I try anything just for my own comfort. At the mo the engine is wringing wet with condensation. Glad I sprayed the block and liners with WD40 after cleaning them.

 

I presume that the factory worked at a relatively decent temperature, but Czechoslovakia gets horribly cold in winter - -30 deg C being normal. I wonder if there's anything about this in the Cz manuals?

 

This may all sound daft, but the more I dig into this the more I want to know, just to satisfy my curiosity. Apart from a job hopefully well done a lot of the satisfaction I get from a something like this is putting together knowledge to gain understanding. It always seems to come in useful somewhere else.

 

Incidentally BGA's technical bulletins give a couple of scary pictures of stretched headbolts: http://bgautomotive.co.uk/bulletin-sealing-range/  and look at TB-0707-092013 (PDF).

   

6.    Oil. I've checked my Skoda Owner's Handbook. Skoda say 20 / 50 is good down to -10 deg C. It rarely gets that low in this part of the uk, even at night.

 

I know far too little about oil. The thought about lubricating the bolts with something with EP properties rather than standard engine oil was mainly fishing for advice. I know a little about how EP additives work in gearboxes, but that's acting chemically steel upon steel. The effect seems not to be instantaneous, so probably no advantage steel bolt screwed once into ally. Any disadvantages? Don't know. Standard engine oil it will be. I know that there seem to be some special bolt lubricants out there - anyone any experience? Read somewhere in the last couple of days a suggestion to spray the bolt and head with white lithium grease. I can see a possible advantage in using a dab of lithium grease under the bolt head / washer, but I'd be very  hesitant indeed to grease the thread of a bolt going into a blind hole.

 

Thanks everyone for your interest and advice.

 

Jxx

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Jxx

Relax. Breathe. Relax.

You did great so far. You've managed to remove the head bolts in one piece. You saved the cylinder head from the bin by welding. You cleaned the holes and the threads. But don't overdo it by splitting the hair in half (aka paranoia). It's not like you're doing brain surgery on your kid. It's a gasket and a 'cap' held by 10 bolts. The only 'scientific' thing coming is the torque of the bolts in order by the book. The 90 deg. torque stages? Easy. I do it by eye. I locate the torque wrench in line with the cylinder head then I torque in one continuous motion till the wrench is perpendicular on the head.

 

Now about your worries.

No, I will not kill you for reusing the valve stem seals :D But if you'll experience high oil consumption, remember my advice. You'll have to change them on the car using my method. The good thing is that you're willing to learn new things. Practical knowledge is gold.

The bolts, oh, the bolts. It doesn't matter so much if the engine is cold or warm. That is nothing compared to millions of explosions in the combustion chamber the head and bolts have to endure, isn't it?

About BGA: they know their stuff but remember, Skoda factory bolts are not stretchable. BGA acknowledges that, so those scary illustrations don't apply to your case. 

The oil for the bolts: chill, any engine oil will do. The oil has the role of allowing the bolts to screw in easy all the way without interfering with real torque values.

 

In conclusion, let aside any inexistent problems. Let us worry about them if it is indeed the case. You'll be good.

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Ricardo

Thanks for the info re BGA are ok. Have just ordered a set of bolts off a company on fleabay for £35. They've got a 100% rating, and wanted me to confirm reg no / engine no, so they seem to be quite professional.

I gave the top of the block and liners another spray with WD40 yesterday. It's been cold and foggy here and everything's wet under the bonnet. I don't want any rust on the liners, especially the tops. I'll sort out degreasing when I fit the head.

Also ordered a set of BGA seals from someone else. I'll fit them if they arrive in time. My spring compressor is too small for the favorit head so I'll either have to buy a bigger one of make up something like the "spanner" one you posted a picture of.

I've had a search on the forum I can't easily find it again - got a link?

General question - If this has to be done with the head in situ at any time the rockers will obviously have to come off, that means 2 head bolts out. I presume it is necessary to release all the others in sequence at the same time?

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My spring compressor is too small for the favorit head so I'll either have to buy a bigger one of make up something like the "spanner" one you posted a picture of. I've had a search on the forum I can't easily find it again - got a link?

It is a cheap #20 spanner with a hole drilled in the right place, A magnetic rod will come handy to recover the keepers. Use grease on keepers at installation time to hold them in place.

 

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Kh9gWJn.jpg

 

 

General question - If this has to be done with the head in situ at any time the rockers will obviously have to come off, that means 2 head bolts out. I presume it is necessary to release all the others in sequence at the same time?

You don't have to release all the other bolts. But you need to drain all the coolant in the block to minimize the seepage in the threaded holes for the bolts. Even so, a very small quantity of coolant will seep in and will have to be dried out before re-inserting the bolts.

 

J8ypLGY.jpg

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Dear Ricardo

 

Very many thanks for that - looks far easier to handle than the "proper" tool. It's roughly what I remembered. I'm sure I can knock something like that up. I like the idea of the packing washers to keep the spring down. I was mulling over the idea of a second bolt and a small block to protect the top of the head, but simplicity is best!

 

(There's another reason to pop the valves. I've noticed that there is a small wear ridge on the top of a few of them, which will make setting tappet gaps awkward. It'd be nice to hone them flat.)

 

I guess from the stat housing that that is a Felicia. I noticed from the pictures of the nut and bolt locations you posted that the M8 nuts were stiffnuts.

My favorit has flat washers, split shakeproof washers and ordinary nuts. I wonder why Skoda changed? Just checked the 2 Favorit partslists I've managed to grab off the net - plain nut 8.87 - 01.94, hex nut, self locking, N0111849 02-94 on. No mention of any split washers except on the bolt for the alternator bracket.

 

I did notice when I removed them that they seemed quite easy to remove.

 

The other thing I noticed on my head was that the central head bolt fixing hole inside the tappet cover area was lower than the others. I see your Felicia head is the same. ??

 

Just had an email from the bolt supplier. Dispatch confirmed for tomorrow. I had to get the seals from someone else, projected delivery 6 - 9 jan.

 

I really DO NOT want to do that job later with the head on. I'll wait unless I have trouble with the Metro. (I do have to have a working car at the moment

for work and with my wife up in Suffolk 60 miles away with her dad. Also, I'd like to get that head off the stool in the kitchen where it's living at the mo. Perhaps its a good job my wife's away at the moment ....

 

Jxx

 

Regarding draining the block ... the drain point in the block was really tight - I presumed it was seized in so quit while I was ahead and drained from the bottom hose. I had a small weep from there anyway, so I'll change the hose when I refill. I couldn't be bothered at the time to crawl under and remove the drain plug in the bottom pipe.

 

Looking at your pics,the other thing I'll have to do sometime is replace the vapour lock device on the pierburg. The plastic is beginning to craze slightly. That's a leak I DON'T want to have. At the mo I haven't been able to source one anywhere - strange because I presume they were used on a lot of cars. I'll try again in the spring. If I get no luck I'll fabricate something out of copper pipe. Could be cheaper and quicker in the end.

 

 
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Skoda installed Favorit engines (code 135, 43kW) on all Felicias with carburettor. That is why the similarities. The last photo shows the car of my best friend while I was teaching him how to do the valve stem seals replacement job in-situ while I took photos. He was in the process of feeding thread in the combustion chamber (piston down). The piston was then raised for the thread inside to serve as a cushion for the valves during valve spring compression.
 
Re. the vapour separator. Again, as I said before, easy to find on the continent. Somebody is doing a 'great' job isolating ('protecting' ?) your island...
 
https://www.google.co.uk/search?q=115940153

Edited by RicardoM
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The story so far:

 

The BGA bolts arrived on wednesday. Correct ones this time. They all have the correct 10.9 marking, also 5 stars. Purely out of interest, does anyone know if that is another grading code or a manufacturer's code? The bolts look a lot nicer than the wrong Victor Reinz ones I was supplied earlier. Better packed and far fewer nicks in the threads, better than Skoda OEM for that.

 

I'll give them a careful look over, carefully relieve any significant nicks and test fit them into all the holes first. some seem a mm or so longer than the originals - I'll screw them in by hand until they bottom out, measure protrusion from the block and double check things are ok especially as the head has been skimmed.

 

BGA supplied a sachet of "Special grease for cylinder head bolts". I'm a little cagey about this. If I use it I presume it's essential to get it to the bottom of the threads, so a very light application with a toothbrush? Or possibly a thicker smear right down the threads but not all the way round the bolt? No instructions supplied. I'm inclined to ignore the grease and just lightly oil as normal.

 

Bad news with the seals - Correct BGA part no bag supplied (another supplier), but had a very small seal sized tear in it Seals were smaller than 8 mm - loose to the shank of a 6 mm drill, just smaller than a 6.5 mm drill shank - so I guess for a 7 mm valve. Will have strong words with that ebay supplier shortly.

 

I made Ricardo's valve spring tool and popped one of the exhaust valves. The old seal still seemed to have some tension on the valve left, and did not seem to be burnt at all. I've decided to leave well alone and risk it.

 

I have to get this job finished. The weather here has been foul all this week but Mystic Met were forecasting mild and dryish over the weekend. Mind you, an hour is a long time in weather forecasting in the UK these days, and they're now suggesting rain on sunday. If it looks reasonable I'll have a bash.

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The BGA bolts arrived on wednesday. Correct ones this time. They all have the correct 10.9 marking, also 5 stars. Purely out of interest, does anyone know if that is another grading code or a manufacturer's code?

Read this.

 

Re. nicks on threads... come on... you'll end up sleeping with those bolts nicely aligned on a pillow next to you :D

About the grease: you can use it. Smear the threads all the way. It doesn't matter how much you apply, the excess will stay out when screwing the bolts in. The oil is more problematic because if it is in excess it could fill the hole and when torqued the bolt could compress the oil and crack the block. But we're splitting the hair now.

 

Relax.

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Foul day here today in spite of what Mystic Met promised. Forecast changes with the hour. Mild but bouts of very fine west country type rain. However - I took one of the old bolts, cut a couple of slots in the thread with a hacksaw, brushed it out well to remove burs and had another at the threads in the block.  Cleaned the wd40 out well with a bits of paper towel wrapped round a long thin screwdriver. (Compressor's a big heavy brute in the shed at the bottom of the garden, didn't want to lug it out if I could help it.)

 

Very little further muck came out and I can see the bottoms of the holes are clean. Had a look at the new bolts, threads all good - no nasty damage. Gave them all a good clean with a stiff brass wire brush - the long and short ones had a bit of spotting corrosion and felt a bit rough. Decided to run them down dry into the threads finger tight to the bottom to make sure all ok.

 

I ran a straight edge over the block. As far as I can tell it's true. The liners seem pretty well level with the block rather than protruding slightly, but there's nothing I can do about that.

 

Measured the protruding lengths with the new bolts out of curiosity to see how much room there was. I used a digital vernier which I have always found very accurate and reliable up to now, but I've not used it needing high accuracy over an inch or so. I'll check it against a "real" vernier calliper I inherited from my father tomorrow.

 

Measured the head - 97.6 mm after skimming. Allowing for 4 mm for the air cleaner bracket, 4.2 mm for the washers and 23.9 mm for the rocker shaft clamps and I did a few quick calculations. Head gasket is 1.5 mm new. No idea what it is compressed - 1 mm?? Had some difficulty getting in to measure the protrusion of bolt sticking out of the holes which take the bolts under the rocker shaft, I'll try again tomorrow using the depth gauge bit of the callipers. So far I've only got rough ruler measurements for them.

 

This is what I get, with a finger tight untensioned bolt:

 

Short bolt (no.10) (New bolt 0.5 mm longer than old Skoda bolt)

Protrusion 100 mm. Head + washer + gasket @1 mm = 102.8 mm --- Gives 2.8 mm to torque down  --- tight.

 

Medium bolt. (new bolt 0.8 mm longer than new Skoda bolt) Manifold side:

No.6 - Protrusion 104.5mm Head + air cleaner bracket + washer +gasket = 106.8 mm --- gives 2.3 mm to torque down --- tighter.

No.2 - Protrusion 106 mm --- gives only 0.8 mm.

No.3 - Protrusion 103 mm --- gives 3.8 mm.

No.7 - Protrusion 100 mm --- Head + washer + gasket = 102.8mm --- gives 2.8 to torque down.

 

For the medium bolts under the rocker shaft I only have a rough ruler measurement at the moment, but I suspect that the middle bolt, No.1, which for some reason is set about 4 mm down in the head will be tight.

 

For the long bolts I get : No. 9 - 4.5 mm to torque down, No. 8 - 7.5 mm to torque down.

 

Now, I will check this all again and check the accuracy of the callipers, but these figures don't look right. Or I've made some silly error somewhere.

 

I've noticed with the medium bolts that not only are they 0.8 mm longer than the original, the threads are rolled all the way to the end of the bolt. The Skoda ones have the ends nicely rounded. I'd be very surprised if the tappings in the block have no run out.

 

If - and it may be a big if - my measurements prove correct I'm tempted to grind the ends of the bolts down to at least OEM sizes, and round the ends of the medium bolts slightly. I'm pretty sure that the threads in the block are clean , but I'll check that as well.

 

In the meantime I've got a few questions:

 

1.   How much spare depth is considered normal / safe for the threads in the holes in the block? Obviously I need as much used thread as possible for strength.

2.   How much should I expect the head gasket to compress when the head is torqued down?

3.   How much do the bolts stretch under tension - after all they are effectively a mighty strong spring.

4.   I've measured my head at 97.6 mm. Does anyone know the height of a stock Favorit head? The number 0881 is stamped on the head, top centre, manifold side.  I don't think the machine shop took that much off, there's still some way to go to the marker notch - difficult to measure as it's rough cast, not machined.

 

Thanks everyone for your patience - especially Ricardo.

 

Jxx.

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1.   How much spare depth is considered normal / safe for the threads in the holes in the block? Obviously I need as much used thread as possible for strength.

There is nothing written in stone. I'd go for 1 mm.

2.   How much should I expect the head gasket to compress when the head is torqued down?

Around 0.5 mm.

3.   How much do the bolts stretch under tension - after all they are effectively a mighty strong spring.

I am not expecting any stretch.

4.   I've measured my head at 97.6 mm. Does anyone know the height of a stock Favorit head?

Sorry, no info on that. Maybe somebody else can help.

The only problem I see is bolt no. 2.

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Thanks for that, Ricardo. Just seen your post.

 

Nice to have my somewhat uneducated guesses confirmed. My main worry was no.2.

 

I've checked my digital "vernier" against another one and a real mechanical one, and checked the bolt protrusion measurements. Coming up with the same figures.

 

I've had a good look down the holes in the block. The holes go rather deeper than the threads.  The threads in the holes are clean, but are a tad rough looking. I suspect they've seen better days. That was my guess yesterday, and trying to tighten down a bottomed bolt would be bad news.

 

Problem is, I don't know how much the guy took off the head. At a  guess no more than a mm - probably a bit less. There's still about 1 mm left on the maximum machining notch. I've got a nasty feeling the thing might have overheated in its early days and the head skimmed before. Someone's put an override switch on the radiator fan - I've certainly never had overheating problems, although it's possible the first owner was panicked by the temperature gauge rising very slightly before the fan kicks in.

 

Have you any idea how deep that max machining notch would be on an original head?

 

I had already decided to grind back the ends of the new bolts to the size of the Skoda part, and gently cone off the ends to match.

I'm coming to the view that it would probably be safe / safer to take another mm off the bolt for no.2 to allow for the machining.

 

Alternatively I could add an extra washer under the thick bolt washer. The only ones I have available are ordinary 1.2  X 10 mm x 25 mm penny washers - trivial to open them out to 11 mm. The original hardened washer would be up against the bolt head, and I presume the  air cleaner bracket is nothing special. The other one I would need to check is the middle bolt on the other side - no.1 - the one recessed into the head under the rockers.

 

The only way I could see of getting a better measurement for that row was to carefully put a bit of masking tape round the bottomed bolt in the head and measuring with callipers  after I took the bolt out again. Got to be more accurate than trying to look at a ruler. Or engineer's callipers and measure them if I've got some suitable.

 

Very many thanks for all your advice Good not to be doing all this on my own.

 

Jxx

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Why not put the bolts thru the head and measure how much is sticking thru then compare how much they screw into the block? Just to make measuring the head thickness easier if nothing else.

If the max skim mark is still visible then I can't see why they would be bottoming out unless the block has had a skim which is unlikely.

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I doubt the bolts will bottom down. On hole no. 2, there must be some debris inside or a bed of solidified rust. I remember you saying that you replaced the head gasket 5-6 years ago by just slapping it in. Well, that might come and haunt you now.

 

So, take a sharp steel scraper and try to dislodge whatever might be on the bottom if hole no. 2. Leave the bolts alone.

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The machinist (firm) should be able to say how much they planed off the head.

 

You can do a "trial assembly" in which you only spin the bolts up finger tight to check that they aren't bottoming out in the block.

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Hi Ricardo.

 

From what I could see with a torch before, all the holes looked clean. This morning I stuck a camera down all the holes to try to get a better look. That was all I could do before the rain set in.

 

Unfortunately,  the kind of inspection camera I can afford that is thin enough to fit down a 11 mm hole is fixed focus and low resolution, but the image clearly shows that the thread does not go down to the bottom of the hole (none of them do) and that the hole is clear to the bottom. You can see where the end of my screwdriver scraped the bottom of the hole when I was using it with some industrial grade paper towel wrapped around it to clean out the wd40.

 

It's also clear where the bolt has bottomed and polished the end if the thread as I ran it up and down with wd40 to clean the threads.

 

I'm putting it down to manufacturing tolerances. I guess it was near the knuckle before I had the head skimmed. My memory of the machining limit was getting on for 2 mm before I took the head in - it's just about 1 mm now. Difficult to tell exactly because the notch is rough cast not machined. So maybe they took getting on for 1 mm off?

 

I've decided to grind a mm off the end of the new bolt for that hole. Don't want to take much off because the thread in the block is not much more than 25 mm judging by the marks on the old bolts when they came out. I'm actually more concerned about the somewhat tatty threads I can see with the naked eye in nearly all the holes in the block, but there's nowt I can do about that. It's not nearly as bad as it seems in the photo - pixelation due to the appalling resolution - 640 x 480.

 

The other thing I can do is **gently** lower the head onto the block without a gasket, fit the bolts finger tight and see if any actually bottom out then.post-151435-0-54943900-1484011405_thumb.png

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I took the liberty of enhancing the photo of the hole a bit. Everything looks OK except that the hole is indeed not deep enough due to a machining error.

 

I suggest that instead putting the head directly on the block, use 1 mm thick cardboard to act as the crushed HG. Of course you'll have to cut 14 holes in it. Next screw in the bolts finger tight. If they will touch the head you're good.

 

For extra care you can smear the bottom of the hole with a bit of grease to see if the bolts touch it.

 

tKM2xXZ.jpg

Edited by RicardoM
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Good idea, Ricardo.

 

Finally got the head back on on wednesday. Weather's been absolutely foul here, and trying to fit this in urgently when I can with other work.

 

I actually very carefully laid the head directly on top of the block, inserted the bolts and checked that way. I carefully took a mm or so off the ends of a couple of the new bolts, and marked them with a felt tip pen.

 

As I said, the new bolts were supplied with a sachet of "special grease" I decided to use this. I was a little bit worried that it seemed to contain a very small amount of copper powder, A flame test confirmed copper ... oh, well, I hope they know what they are doing. Only a very slight amount - the grease was almost transparent. I'll try to post a photo of the greased bolts later. (Not loaded with the stuff like copper ease.)

 

I carefully removed the head and  ran a bolt down each hole a couple of times to make sure the grease got to the bottom of the threads in the block, removed the bolt, cleaned and re greased it each time. Not over happy with the feel of the bolt as it went in the first time - the next time I do this (hopefully never again on this car) I think I'll stick with oil.

 

Then cleaned the block again with with white spirit followed by acetone, cleaned the head again with acetone, fitted an new manifold gasket the (right way round - it's symmetrical), spread copperease on the manifold studs, fitted the head gasket to the block (checking it's the right way up) and laid the head on the gasket.

 

Dropped in the push rods in the original order, fitted the rocker arm assembly with the tappet adjusters unscrewed and made sure that the ball on the adjusters was correctly in the top of the pushrods. Fitted the new bolts into the appropriate holes and did them up finger tight. Then tried to fit the rocker shaft bolts through into the head.

 

ERROR. I should have fitted the small bolts first. There is a cut out in the rocker shaft to take these bolts, to locate the shaft. I had to undo the 2 long head bolts a few turns to enable me to turn the rocker shaft to get the small bolts through.

 

Then torqued up the head bolts as per spec. Then fitted the alternator mount and torqued the the head nuts.

 

HINDSIGHT - It would have been good to make a copy of the tightening sequence diagram and ticked off each bolt 3 times for each sequence - prevents errors if you get distracted during the process.

 

That was it for wednesday - dusk.

 

Thursday was mildish but damp. I removed the drain plug from the sump, a little more oil came out as expected. A bit of paper towel into the sump did not detect any coolant in the bottom of the sump. Replaced the plug and changed the oil filter.

 

Adjusted the rocker clearances, replaced the rocker cover, refilled with cheap oil. Cleaned off corrosion from the alloy pipes on the inlet manifold, stat housing etc, checked and refitted the hoses. Filled with 33 %  blue antifreeze. Replaced thermistor cable, spark plugs plugs and leads.

 

Started to drizzle slightly.

 

Decided to try to get the manifolds back. Carefully knocked out the little wooden block I had inserted to keep the exhaust pipe and manifold back - (it's possible to push the manifold back enough to remove the head without disconnecting from the exhaust), and fitted the washers and nuts.

 

Next, the inlet manifold and carburettor. Problem - the bottom inlet manifold nuts are almost unreachable with the exhaust manifold in place. It's worse the other way round. In the end I fitted the top washers and nuts very loosely, got the washers on the studs with a pair of long nosed pliers, adjusted the heatshield slightly with a drift and hammer, lifted up the inlet manifold on the top studs and managed to get the nuts on and tightened with a slim  1/4 in drive socket and extension. The state of the heatshield and fixings meant removing it for easier assess was not a sensible option.

 

Attempted to start the beast. By now it had been drizzling steadily, and despite some wd40, no go. Decided to go in and dry up / warm up, and leave it for the day. Had to go out a bit later, returned after dark. Noticed that I had left an interior light on - I've got a pair of 20 W halogen spots in the roof - so I thought I'd give it another go if only to check if I needed to put the battery on charge. Much to my surprise it started immediately.

 

Let it warm up, lots of water vapour out the exhaust, expected of a cold wet day. Let it warm up. No bubbling out of the coolant filler. Let some of the water vapour out of the back  condense on my hands and licked carefully. Slightly sweet, nowhere like as bad as before. Probably residual in exhaust.

 

Waited till the thermostat opened, no overheating. Coolant level had dropped from max to min. and seemed stable. Switched off. Oil level slightly lower - expected as the oil filter and galleries filled. Started it up again later and warmed it up again. Levels stable. No more discernible taste out of the back end. Hopeful.

 

Fitted the air cleaner today Took it out on the road for a few miles locally. Seems to run ok apart from the tappets. Would expect that as the pushrods etc settle in.

 

Will treat it carefully and use for local trips for a while to make sure. Thanks everyone for all your advice!

 

WARNING. Antifreeze (and brake fluid) is toxic. Do not ingest. It can also pass through the skin into the bloodstream. Having said that, it is VERY sweet, and not so long ago cheap wine from a european country which shall be nameless was found to be sweetened with antifreeze.

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Well dome! Keep us posted. The final test should be a high speed trip with sharp accelerations from 1st to 4th speed. Floor it.

Question: what would you do different?

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  • 1 month later...

Sorry I've not reported back sooner. Life has been horrendous here recently - I've barely had time to breathe. Also I've been working locally recently (2 miles or so each way town driving most of the time) and not had the opportunity to give the car a decent trip. (Apart for the weekly trips to see my wife, who's staying looking after her 96 year old dad at the moment. That's a 120 mile round trip, but I wanted some confidence in the car before I went so far from home.)

 

I've had a couple of longer work trips, and had it up to 50 / 60 mph, so this sunday I bit the bullet and took it up to see father-in law.

Mixed country road motoring with some decent fast stretches. Coolant level seems constant, holds reservoir pressure after 15 mins or so, so I don't think coolant is going anywhere. There was a very tiny amount of mayo in the oil filler cap after the short runs,  now all gone after the longer trips. Lovely day on saturday, so I had the plugs out after I got back from work. All looked ok, but gave 'em a clean before I put 'em back.  

 

All went well, so I think we can mark this one as "solved". Many thanks to everyone for your input.

 

What would I have done differently?

 

1.   I would have oiled the bolts rather than using the grease supplied. I think it would have been easier.

 

2.   I changed the first hose down from the radiator because I had had a slight weep from the connection to the rad. I would have liked to change the other 2 underneath, but access is not easy. In ideal conditions (summer) I'd have refilled with plain water, and got the car onto ramps for access. I've had the hoses for a while, but never had time to do the change. (initially when I finished replacing the head I had a very small leak from the bottom of the radiator by the outlet pipe first evidenced by a tell tail trail of water vapour from the area. I let the radiator get nice and hot with the filler cap removed to prevent the system pressurising and sprayed the area with fresh water to clean it as far as I could. When it was dry I pressed in some Fernox LSX, a plumber's silicone sealant specifically designed as a jointing compound and leak sealer. The small weep seemed to be from one of the bottom cores of the rad, right in the corner by the outlet. I gave this several hours to cure, tightened down the filler cap and it seems to have cured the problem. I'll have to keep a close watch on this area. I then noticed a small weep from the outlet hose / radiator joint itself. Easily cured by nipping up the jubilee clip. Truly, Murphy is a sadist.) I'll leave the other hoses till the spring.

 

3.   The heater matrix is quite blocked up, heater is very poor. Had been like this for a while. THAT IN ITSELF SHOULD HAVE RUNG ALARM BELLS. I would have liked to backflush it properly, clean out the control valve etc, but the weather and time made me decide to leave it all to the spring. I'll change the antifreeze again then.

 

4.   With hindsight, now knowing the cause of the rotten gasket and head, changed the antifreeze every 2 years!

 

5.   I think undoing and pulling back the manifolds first and removing the head without them was a good idea, even if getting the nuts back on the studs was a bit of a pain. It avoided a lot of messing about with the carb, and I've never tried disconnecting the exhaust from the manifold from above. (Always done it from below with the car on ramps - easy that way.)

 

UNRELATED INFO.

 

The front downpipe (My car is without catalyst) always seems to rust out at the weld with the flange which joins with the mid section. Aluminium paint rather than aluminising. The last unit I got off Skoda was wrapped in plastic bags and selotape. There was some selotape still stuck to the pipe when I fitted it. This has burnt off and taken the aluminising with it, leaving a rusty patch. Something else to look at in the spring. Worth checking that a new section is clean before fitting.

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10 minutes ago, Jxx said:

3.   The heater matrix is quite blocked up, heater is very poor. Had been like this for a while. THAT IN ITSELF SHOULD HAVE RUNG ALARM BELLS. I would have liked to backflush it properly, clean out the control valve etc, but the weather and time made me decide to leave it all to the spring.

You'll find that it's not the core of the heater matrix that is clogged. It is the outer fins. After years of unfiltered air passing over/through it, the heater looks like a solid brick. I know people in colder countries that had to use the strongest oven cleaner on the 'bricks'. They let the solution foam for 15 minutes and eventually light could be seen through the fins. Plenty of heat after that. By the way, there isn't any 'control valve' for the heater circuit. Hot coolant passes all the time through the heater. Cold/hot air is regulated using air flaps.

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Hi Ricardo.

 

That's a new one on me. I don't doubt that there's a lot of dust on the outside of the matrix. Most oven cleaners are strongly caustic. What's the matrix made of? will they damage it?

 

Anyway, on my Favorit, the cable from the top (temperature) slider in the car goes to a lever under a black plastic box connected internally to something my parts list refers to as a regulating valve. 2 plastic pipes out of that valve cover connect to the heater flow and return hoses. Do they do it differently where you are?

 

At least the heater matrix is easy to get at. In my metro it's built in under the dash.  A day's work to get it out. That has air flaps. At least you get instant warmth when you operate the slider. Warmth, not heat. Metro heaters are weak. The Favorit used to be toasty.

 

 

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