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.
