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cylinder head removal


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So, still working to take this off.

 

The car has a stainless steel exhaust, 4 into 1, and it won't come out without, it seems, removing the starter motor as it has no bracket from manifold to down pipes that can be undone, unlike the original. And it cannot be pulled out far enough off the studs as it hits the chassis at the bottom.

 

I assume that when these are put on the starter motor has to come out. Anyone done this? I'm hoping for a simple and clever way not to have to take the starter out and be able to remove the exhaust manifold. Not optimistic.

 

Dave

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Remove the bolt holding the exhaust to gearbox, loosen the exhaust clamp holding the Y piece (if you have one) or any other clamps in that area. This should then give you enough room to twist the headers out of the way and use a timber wedge to hold them back.

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Thanks.

 

That's pretty well what I just did. Only one nut holding the whole thing to the car - at the very end of the chassis. I'm surprised it hasn't shaken itself to bits. Undid that nut, then tried to undo the first ubolt/clamp at the 4way/1way junction. Bliss. Both nuts sheared off the ubolt, skinned knuckles as usual. In frustration I had another go at the manifold - it seems that undoing the solitary nut allows the whole thing - backbox, pipe and manifold to swing just enough under the car to clear the studs. Exhaust now out of the way.

 

A few judicious bangs with a Brumagem screwdriver and a bit of wood and the head is loose and ready to be removed. Now where is my trusty assistant? Got to hunt the boy down.

 

Thanks for your help.

Dave

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Ha, assistant unwittingly appeared at the garage. Cylinder Head now off with help of a little chain hoist, rope and said assistant.

 

In the process of undoing the head nuts one came out with the whole stud bolt rather than just the nut and washer.

 

And, good news, the head gasket looks blown at the back of nr 4 cylinder, and the bore shows stained signs at the very point of the blow, which I am assuming is steam/water stain. Good news in that I cannot see any cracks in the block. I'll have another good look tomorrow.

 

 

Few bits and pieces to do when it goes back together (exhaust brackets for one).

 

Any recommendations about what I should also be doing while the head is off? Clean out water ways I guess. How to cover the pistons so I don't get rubbish in there?

 

Any suggestions/recommendations very welcome.

Cheers

Dave

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Cheers

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Make sure that the liners are held in position (see Workshop Manual), just in case you inadvertently move the crankshaft.

Remove the coolant drain cock from the rear of the block and clear as much as possible of any accumulated sludge - if bad and difficult to shift, use some solvent (see another topic which is active at the moment).

Check deck heights of each of the liners - should be between 3 and 5 thousands of an inch.

By masking, prevent loose material, such as carbon deposits, falling into the oilways and waterways.

Make sure that the pushrods go back in the positions whence they came!

Ian Cornish

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Quite common for the gasket to fail at number 4, check the search facility for details.

 

However bottom line is No 4 runs the hottest (furthest from the water pump and is fed hotter water because of it). The excess heat allows deformation of the rear of the block after many hundreds and thousands of stop start cycles and hot/cold/hot cause the studs to lift the block material at the rear. This reduces the clearance on the rear liner to the block and also it's clamping force, hence it blows the gasket.

As Ian says clamp the liners in position using tubes or old gudgeon pins and washers on the studs inbetween where the conjoined liners are. Apply a minimum of 40lbs ft here and then measure the liner protrudences around the liners to the block face.

Measure in 4 positions around the liner top (depth micrometer if possible but a straight edge and feeler gauges if you can use them well) and write it on the liners tops in permanent marker. You are looking for an even measurement in between 3 and 5 thou around each liner and equal if possible along them all ie 4 4 4 4. You can get away with a small run out ie 4 4 4 3 tapering to one of the ends, because the seemingly massive head casting can and will deform under torqueing, (there are no other liners at the ends the same height to prevent it) and take it up. But if the height reduction in a liner clamp is between two liners in the centre of the block eg 4 4 3 4 they prevent the head deforming and correspondingly the pressure and liner clamp is reduced and allows a future possible gasket blow.

Check the head inbetween the valves for cracks and also the waterway in the centre of the block on the web and the corresponding holes close together in the centre of the head.

 

Don't rush this and think that close enough will do, you wouldn't mind to be doing this again in 120,000 miles but under 5,000 miles and you will be peeved.

 

Mick Richards

Edited by Motorsport Mickey
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Thanks fellas. Did the liner retention pieces, and measured the depth. From what I measured with the feelers they are within the tolerances but I really need a depth micrometer to get a better measure.

 

Spent the day cleaning things. Valve faces in no 4 were covered in some sort of water deposit encrustation following the blown gasket. Cleaned up well though.

 

I have noticed that there was no gasket sealant on either face of the old head gasket. Surely there should be something there. The WSM is a bit vague in that it says coat the new gasket with jointing compound, but doesn't specify one or both faces. Any recommendations? I have done a bit of search and the Loctite grey stuff seems highly recommended.

 

No cracks between valves that I can discover.

 

Not sure what "on the web" means?

 

The two holes in the centre of the head are sort of tear-drop shaped is that right?

 

Cheers

Dave

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On the advice of the forum I've used Blue Hylomar aerosol spray on both sides of the gasket the two times I've installed my cylinder head. It's easy to apply evenly being an aerosol. Testament to how good it is - when I had to remove it recently so it could go to Peter Burgess the head came off without any bother at all and the gasket was nice and clean.

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The web is the area on the block in between the central liners and directly under those 2 teardrop shaped holes in the head. It attaches both sides of the block together. In a competition engine I was going to work to "weapons grade" calibre if it was cracked I wouldn't be expending lots of effort on it, it would be put to the side and another of better quality selected.

 

Mick Richards

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Thanks for the suggestions.

 

I like the idea of a spray to give good coverage.

 

Was it this one: Hylomar Universal M Aerosol Gasket Sealant ?

 

Dave

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Head back on and torqued up to 45 lb ft as in the Haynes manual "put it back on" section.

 

I double checked with the WSM and the only reference I could find says "cylinder head1/2" unf and bolt -- 100 lbs ft".

 

Now the socket I used was 3/4", but then I am not a nut classification expert - 1/2" unf could well be 3/4" as far as I know. Should it be 100 lbs?

 

I saw Mick's note above about a minimum of 40 lb whilst keeping the liners in.

 

Is it 45lb when doing it up?

 

Your guidance appreciated.

 

Cheers

Dave

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Torque is a huge 100-105 lb/ft. Follow the the torque sequence given in the WSM. To clarify, the threads are 1/2 inch UNF, the socket is 3/4". Also make sure the threads of those High tensile heads nuts are in good condition.

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And only tighten the studs into the block by hand, no torquing them in, if the studs turn when the nuts are tightened they can crack the block.

 

Mick Richards

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That is a serious error in the Haynes manual and could have caused problems for people that have followed it although to be fair in the engine specifications section it gives the correct torque of 100-105 ft lbs.

 

Error is present in my 1971 edition don't know about more recent prints.

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Well, I'm very glad I asked. I was just going to leave it at 45.

 

 

Thanks for your help, again.

 

Can't wait to get it going.

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Good point Mike.....it nearly caught me out 30 years ago.

So did the advice on valve clearance adjustment. I didn't know the rule of 9. Neither did Haynes when they advised to adjust 8 when 7 was open☺☺☺☺

motto of the story use the ST manual!

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Ok. Now torqued up to 104 lbs ft. Lovely. Also did the valve gaps and the plug gaps. Putting the manifolds back on.... disaster... The last stud I did broke off at the first turn of a spanner. Turns out the stud was only good about 1/5th of the distance across the diameter, the rest was rusted through on an old crack or fault.

So now I have a broken manifold stud. On close inspection it has been broken before, there is about a half or one turn of thread on the broken off bit, and the rest is about a half a turn in the block, then it has been araldited or similar back on, just enough to hold it in place with the washer and nut on. You can see the clean bit, and the very rusted part previously broken.

 

I am left with a) drilling it out. and probably retapping.- fortunately it is the top row middle left stud, so access is ok, or B) aralditing it back in and tightening up just as far as I feel safe with it - but this is just redoing the old work-around (or bodge).

 

I think I know the answer but your various wisdoms would be appreciated.

 

Dave

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Hi Dave,

drilling out shouldn't be too difficult. An easy-out may work (or break); there are straight fluted variations on the theme that work better.

 

Or you can go for broke and and drill out complete with the thread and use a Helicoil repair.

 

Roger

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As Roger says the thread is likely well corroded in, plenty of material around it, drill out complete with thread (pilot hole in centre first to make sure you get it central) and Helicoil a fresh thread in.

 

Mick Richards

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After some days procrastination, looking at youtube for tips, planning and buying bits, etc, I tackled this about an hour ago. I decided to try the stud remover method, basically a left-handed taper thing (bought from B&Q of all places).

 

Centre punch, small pilot hole, bit bigger hole, try the stud remover. After a couple of goes, I noticed that the broken stud has been driven further in!

 

MMM, I'd been turning the stud remover the wrong way- idiot. Turned it the right way and hey presto!, the broken stud is out, the new stud is in. I'm so excited it has worked I had to come in type this straight away. Time for a rewarding cup of coffee!

 

 

Hurray. Putting it back together is now back on.
Doubtless I'll be back asking for more help as the next thing goes awry.

 

 

 

 

CHeers

Dave

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Edited by dpb
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Congratulations, getting an "Easy out" to work without breaking is an achievement, now go and buy a lottery ticket !

 

Mick Richards

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