Cylinder head off. What do I do before I put it back?

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Fox67
Posts: 6
Joined: 23 Jan 2022, 14:21

Cylinder head off. What do I do before I put it back?

Post by Fox67 »

Hi,
I have the cylinder head of on my 208 (EB2 engine). It started with a new timing belt and then I realised it wasn´t that much more job to change the valve steam seals because the car use about 1 litre oil per 1000 km (thought this maybe would help a bit?).

Then I had to take the top of because I accidently damaged a valve when taking one seal of :(

I have now changed the valve and grinding it, and changed all 12 seals.
I didn´t take the other valves out while changing seals.

Questions and after thoughts
1. Should I have taken all valves out and cleaned and grinde them to?

2 Do I need to do a leak test with the top up side down and pour water on the valves. Then blow air in the exhaust and intakes to see if there are coming bubbles?

3 Clean the surface were the head gasket is with something like scotch brite?

I don´t want to miss out of something before putting the top back so suggestions before I do are welcome :)

Thank´s :)
PaulC5
Donor 2024
Posts: 305
Joined: 06 Jun 2023, 15:26
x 71

Re: Cylinder head of. What do I do before I put it back?

Post by PaulC5 »

Before putting the head back you could do with checking if the valve guides are worn, if they are the oil use may come back. Many years ago I replaced the valve seals on a car only for it to need new guides later to stop the oil use. I am not too sure how to check for wear but vaguely remember the reconditioners put a valve in a guide and checked to see if it could move a bit sideways (wobble).
Fox67
Posts: 6
Joined: 23 Jan 2022, 14:21

Re: Cylinder head off. What do I do before I put it back?

Post by Fox67 »

Thank´s I will check on a couple of them.
I think I will try to clean the exhaust side atleast before I put it back.
Will try with T-red (T-röd is it called in Sweden) don´t know what its called abroad but it´s some kind of ethanol (it says 50–75 % Etanol, 10–15 % 2-Propanol, 5–7,5 % Butanon och 1–2,5 % Aceton)
I poured it in one of the exhaust chambers over the valve yesterday evening to see if it was leaking. I then noticed that the T-red was somehow dissolving the soot and made it crackle.
Anyway I thought i´ll give it a try to get rid of some of the soot with filling T-red in the exhaust chamber and after that some other degreasing fluid.
ozvtr
Posts: 411
Joined: 13 Oct 2020, 01:11
x 124

Re: Cylinder head of. What do I do before I put it back?

Post by ozvtr »

PaulC5 wrote: 15 Mar 2024, 12:11 Before putting the head back you could do with checking if the valve guides are worn, if they are the oil use may come back. Many years ago I replaced the valve seals on a car only for it to need new guides later to stop the oil use. I am not too sure how to check for wear but vaguely remember the reconditioners put a valve in a guide and checked to see if it could move a bit sideways (wobble).
Yes, install the valve, pop it off the valve seat by about a centimeter, then "wiggle'" the valve side to side. "less than a mm" movement would be acceptable. That's just a quick check, to do it correctly requires the specifications and a dial gauge!!
You should pop the valves out and check the valve faces and valve seats of all the valves, while you can. Particularly the exhaust valves and seats. The valves need to go back where they came from. If the faces and seats look OK I would give them a quick lap (it's not hard to do). If you cannot see a clear ring of contact on the seat, or if it's pitted, I would seek the opinion of a machine shop.
If you had no suspicion that there is anything wrong with the head (I.E. it's never over heated), you can 'assume' it is not warped. If you have any cause to take the head to the machine shop they will check it for flatness as a matter of course.
Cleaning the cylinder head face and the deck, of residue, is the biggest pain!!!!! You can not use any kind of abrasive or scrapers, making the job long and laborious!!!!!! Just plod along. Yes use a plastic scourer.
Clean the spark plug threads, either with a 'chaser' or a new spark plug and solvent. Just get the 'gunk' out of the threads.
If you are re-using the head bolts you must check the specification of the maximum length. Also the bolts MUST be ABSOLUTELY clean and dry. Clean old threads with a wire brush. The threads and holes in the block MUST also be clean and dry!!! 'Test thread' the bolts down into the block, check that they all thread to the same depth and there is no binding. Use small amounts of engine oil or anti-seize compound on the threads and under the head of the bolt, for installation. The friction between the bolt and the head and the bolt and the block MUST be reduced to an absolute minimum. Used bolts can snap if not installed correctly!!!
Installing torque-to-yield bolts is like bomb disposal...you are just waiting for one to go "BANG"! Trust me, you will need a drink after installing all the bolts. :lol:
Fox67
Posts: 6
Joined: 23 Jan 2022, 14:21

Re: Cylinder head off. What do I do before I put it back?

Post by Fox67 »

Thanks a lot for this instructions :)
I didn´t have much time today to continue but I got all valves out and wiggled them. It felt ok.
Next then will be cleaning them and a quick lap to see how it looks.
I have new bolts but I guess I could have reused the old ones. The old ones are only at most 0.7 mm longer.
I cleaned some before taking the valves out and noticed that one of the intake valves had a harder burned sot surface on it.
The same as all the exhaust had.
Does this mean something?? (the last picture)
I did measure the valve clearence before taking the camshafts out and it was the same on that valve as the intake valve beside.
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