Cylinder head removal 1098

[eng622]

Following my post on zero compression seek advice. Looking/started DIY as had two discussions with mechanics. One thinks the head will need skimming the second said it is an 8 hour job, sounds way OTT.
So DIY and a few questions.
Is it best to leave the manifolds on as thinking they give a bit of leverage when trying to move the head from the gasket.
Do you need to remove the heater valve as one bolt looks impossible to undo, can you just take off the hose and cable and leave the valve on the head.
How do you tackle the water bypass hose. Mine looks new and new clips.
Do you remove the thermostat housing or just take of the the hose to the rad.
If/when I get it off what should I be looking for skimming etc.

[svenedin]

I did my cylinder head gasket this year. I had managed to get away with never having to do this job despite owning my Minor for nearly 35 years!

On a Minor it is not an 8 hour job unless there are unexpected complications (which in my case there were). None of it is particularly difficult but it does take a while especially if you have never done a cylinder head gasket before (like in my case).

A good workshop manual is essential and there are some Youtube videos around that you can watch (although the videos that I found are not perfect). The Haynes manual has step by step instructions.

People seem obsessed with skimming heads and blocks but the advice I had from A-series engine old hands including East Sussex Minors was that unless the engine has seriously overheated it is unlikely that a cast iron block and head will distort. Remember many modern cars have alloy heads and even alloy blocks which are far more prone to distortion. You can confirm that your head and block are OK using a straight edge.

You MUST have a torque wrench torque to tighten the head up correctly and you absolutely must follow the correct sequence to torque up the stud nuts (the nuts must be released in sequence as well). Failure to do this could crack the head at worst or at best result in early failure of the new head gasket.

To answer your questions:

1) If you leave the manifold on it can help to lift the head off but it makes it much heavier and also you cannot put the head down flat with the manifold attached. Never put the head down on the ground without putting cardboard down as protection as you could scratch the mating face of the head. Since it appears your head gasket has failed rather badly the head should come off easily so personally I would disconnect the manifold before removing the head.

2) You do not need to remove the heater valve. Just the heater hose and the heater control cable. The nuts are not impossible to remove though but tricky (needs rocker cover off). I once had to replace a heater valve at the side of the road. It can be done!

3) You need to loosen the top clip of the bypass hose before you lift the head off. If it is very new and you know it is then no need to replace it but if in doubt change it.

4) No need to take thermostat housing off

5) Check block and head for flatness with a straight edge.


This thread of mine is about changing the head on my car. It is longwinded and a bit rambling but hopefully has something in it that would be useful to you. Many of the older threads on this subject have lost their photos. viewtopic.php?t=76095

Remember also that you need to remove the carburettor and don't forget the throttle return spring on the exhaust manifold to exhaust clamp. You can remove the carburettor from the manifold and leave the throttle and accelerator cables attached by just moving the carb aside rather than removing it from the car completely. It is good practice to renew the carb to manifold and carb to air filter gaskets if disturbing them as they can get damaged.

The mating surfaces of block and head will need through cleaning. To do this take out all of the studs. Check for "pulled up" threads where the studs go into the block and countersink if necessary.

I am assuming you are familiar with setting up the valve to rocker clearances which must be done once the head is back on and torqued up. Rule of 9's and all that. Don't forget that the pushrods must go back in the same place as they came from. The usual way is to push them through a piece of cardboard in order marked 1 to 8.

Observe the correct torque for the manifold bronze nuts or you could crack the manifold.

For tips on how to properly reconnected the exhaust to the manifold search for threads on this. If done incorrectly it will not seal properly. Very briefly you put a jack under the exhaust silencer and gently jack the exhaust up until it meets the manifold. Then you can install the clamp with a smear of exhaust paste around the join.

Stephen

[rocco]

Well that is as good and detailed reply as you'll ever get!

I've seen some videos on youtube where chaps have laid a piece of glass out on a wooden table, secured the glass with smaller pieces of wood, stuck sand paper of varying decreasing grades to the glass and then dragged a cylinder head back and forth over it to get it perfectly flat. It'll give your arms a good workout too.

Personally, I'd remove everything from the head and replace all the gaskets, just because it's cheap, easy (if you can get studs out) and should save having to mess about with it again for a long while.

[moggiethouable]

A copy of the blue soft backed workshop manual is an essential.
It will show you how to best remove the cylinder head and associated components.
It is one of the easier jobs, personally I would check see if a decoke is necessary too, I just love the sound of valves plopping when grinding them in.
https://www.morrisminorspares.com/misce ... al-p831087 for a new one

[Sleeper]

" sand paper" ?
I think not, maybe emery cloth/paper ?

John ;-)

[olonas]

Others might differ, but when I last removed a 1098cc cylinder cover I removed all the inlet and exhaust manifold fixings and pulled the whole assembly clear of the studs. The reason I did it this way is because on previous occasions I removed the flared exhaust clamp/connection, leaving the manifold insitu, and had a pig of a job resealing it on assembly. Even with it fully cleaned and an application of exhaust sealing paste! A jack was also utilised under the exh. pipe to keep the joint in place while fitting the clamp.

[myoldjalopy]

Yes, I did that as well. Saves a bit of time.

[svenedin]

Others might differ, but when I last removed a 1098cc cylinder cover I removed all the inlet and exhaust manifold fixings and pulled the whole assembly clear of the studs. The reason I did it this way is because on previous occasions I removed the flared exhaust clamp/connection, leaving the manifold insitu, and had a pig of a job resealing it on assembly. Even with it fully cleaned and an application of exhaust sealing paste! A jack was also utilised under the exh. pipe to keep the joint in place while fitting the clamp.

Yes I actually did that and then I tied the manifold to the lever shock absorber with the exhaust still attached. I thought this would save time but actually the movement was enough to break the join between exhaust and manifold and it blew afterwards.

[eng622]

The problem so far is the metal water pipe fixed by two brackets under the head nuts. Stupid design if it is normal, has anyone tried two nuts one for the head and one on top for the bracket or are there other alternatives. You cannot get the thermostat housing off anyway.

[svenedin]

The problem so far is the metal water pipe fixed by two brackets under the head nuts. Stupid design if it is normal, has anyone tried two nuts one for the head and one on top for the bracket or are there other alternatives. You cannot get the thermostat housing off anyway.

Yes it is normal on the later cars like mine and I agree it is daft. To remove the thermostat housing you have to remove the heater return pipe. There are longer studs available and then you can have 2x nuts with the heater pipe bracket in between. I tried this and found that it did not work because the end of the heater pipe would not properly engage with the rubber hose. Clearly BMC did not think it was a huge issue. You would have to partially drain the cooling system anyway to remove the thermostat housing and then you will just have to torque up the 2x stud nuts when you have replaced the heater pipe.

Earlier cars have the heater return pipe on the other side of the rocker cover attached to the manifold nuts. This does not work if you have a manifold with a PCV valve on it (as I do on my 1969 car). This may be why it was changed but I do not know.

Stephen

[myoldjalopy]

"There are longer studs available and then you can have 2x nuts with the heater pipe bracket in between. I tried this and found that it did not work because the end of the heater pipe would not properly engage with the rubber hose."
I don't understand this. What was actually stopping the hose fitting on the end of the pipe?

[svenedin]

"There are longer studs available and then you can have 2x nuts with the heater pipe bracket in between. I tried this and found that it did not work because the end of the heater pipe would not properly engage with the rubber hose."
I don't understand this. What was actually stopping the hose fitting on the end of the pipe?

This is just a picture that I had and does not show it very well but it's cold and dark and I am not going out right now to take another photo!

The heater return pipe dives down vertically and goes into a rubber pipe. If you use the longer studs and 2 nuts with the heater brackets sitting on top of the nuts the pipe is raised up and it will not meet the rubber pipe properly. It is possible to connect it but it is a very insecure connection. If of course a new pipe was made that was slightly longer this would work.

This photo also shows why the earlier pipe that fitted on the manifold side will not work with the late manifold. There's no room.

Stephen

IMG_9256.jpeg (518.19 KiB) Viewed 54682 times

Edit: I have a better picture

IMG_9358.jpeg (2.08 MiB) Viewed 54678 times

[myoldjalopy]

Ah, I see now! Thank you. I thought you were referring to the other end where the heater hose attaches..........
I'm glad I have the SII arrangement where the heater hose runs along the engine bay floor - no bracket and no faffing about with cylinder head nuts

[Bill_qaz]

The problem so far is the metal water pipe fixed by two brackets under the head nuts. Stupid design if it is normal, has anyone tried two nuts one for the head and one on top for the bracket or are there other alternatives. You cannot get the thermostat housing off anyway.

Why are you trying to remove the thermostat housing, just remove the radiator hoses and leave it until the head is removed if you want to take it off.

[eng622]

I struggled to remove the the rad/thermostat hose but in the end did get it off from rad end.
Lifting the steel pipe brackets the thickness of the bracket ~2mm should not effect the pipe engaging in the rubber hose sufficient to not be able to clamp it, or have I missed something.

[svenedin]

I struggled to remove the the rad/thermostat hose but in the end did get it off from rad end.
Lifting the steel pipe brackets the thickness of the bracket ~2mm should not effect the pipe engaging in the rubber hose sufficient to not be able to clamp it, or have I missed something.

Yes the height of the nut. You would be raising the pipe the height of the nut if you are going to clamp the bracket between two nuts. If you do this there is very little of the metal pipe engaging in the rubber hose.

[eng622]

OK made a mistake as bracket will be raised by thickness of nut say ~ 12 mm.
On my car the rear stud as two nuts one for the head other for stab. bar which is a full nut and does protrude from the end of the stud.
Thinking of replacing the steel pipe with a rubber hose with metal inserts at each end, won't look very pro. though.
Are the head nuts 9/16 AF.

[myoldjalopy]

Can't see the point of replacing the pipe with a rubber hose. All the cylinder head nuts have to come off anyway to remove the head. As long as you re-fit the pipe (and the engine steady bar) before the nuts on re-assembly then there is no issue.....

[eng622]

The issue is if you need to replace the thermostat you cannot get the housing off without removing the heater pipe which means undoing two heads nuts, not a good idea.
Earlier 948 engines look to have a copper pipe on the manifold side, assume can be fitted to the 1098. Just missed one on ebay. Guess they are hard to come by.

[svenedin]

The issue is if you need to replace the thermostat you cannot get the housing off without removing the heater pipe which means undoing two heads nuts, not a good idea.
Earlier 948 engines look to have a copper pipe on the manifold side, assume can be fitted to the 1098. Just missed one on ebay. Guess they are hard to come by.

Yes that's true but how many thousands of cars and how many thousands of times have those two head stud nuts been removed to replace a thermostat? You have to drain the coolant (partially) to replace the thermostat and then the water level will be lower than the top of the block. Providing the engine is cold and the nuts are re-torqued correctly, what is the problem? It does seem a silly design but in practice I am not aware it's an issue. Admittedly I am only speaking for my car here but it has had multiple thermostat changes in my nearly 35 years of ownership and I have only had the head gasket go once (and even then it was an oil leak not total failure and furthermore my oil leak was on the other side so not related to those to nuts at all).

Stephen