cylinder head

The cylinder head covers the top of the cylinder. The head and the gasket seals the cylinder so that the piston can compress the air fuel mixture. The cylinder head contains the cam shaft that runs the distributor and the cams on the shaft push the rockers that push the valves open. The intake valves open to allow the fuel into the cylinder and the exhaust valves open the cylinder to let the exhaust fumes out. when both valves are closed the cylinder should be air tight.


head dis assembly sohc engine
place all bolts and parts in a labeled container

1. remove rocker cover bolts and remove rocker cover.
2. remove head bolts and take the cylinder head off of the engine. (when removing these bolts take them off in a spiral order starting at cylinder 1 exhaust rocker arm then cylinder 1 intake rocker arm, cylinder 4 intake, cylinder 4 exhaust, cylinder 2 exhaust, cylinder 2 intake, cylinder 3 intake and cylinder 3 exhaust)
3. remove rocker arm bolts and take of rocker arms. (when removing these bolts take them off in a spiral order starting at cylinder 1 exhaust rocker arm then cylinder 1 intake rocker arm, cylinder 4 intake, cylinder 4 exhaust, cylinder 2 exhaust, cylinder 2 intake, cylinder 3 intake and cylinder 3 exhaust)
4. remove camshaft sprocket.
5. slide camshaft out of cylinder head.
6. using a valve clamp compress valves and remove valve keepers at the top of the valve stems.
7. repeat for the remaining valves. 

 cylinder head tests

valves:
valve stem ovality: to test valve stem ovality use a micrometer and measure at three different points along the valve stem compare these measurements withe the manufactures specifications to see if you need to replace the valves
camshaft: to measured the camshaft journals and came lobes using a micrometer and checking that the measurements are correct according to the specifications. we also measured the camshaft end play using a dti gauge that was attached to the end of the cylinder head.
cylinder head: we used a straight edge to test the warp in the cylinder head. to do this we used a straight edge placed on different sections of the cylinder head and used a light to see if there was any gap. if it looked like there was a gap we used a feeler gauge to test the measurements of the gap. if the measurements were larger than those specified by the manufacturer the you will need to have the cylinder head skimmed or replaced.

re assembly of the cylinder head

1. put valves back in the correct places.
2. place the valve springs on top of the valve.
3. using the valve clamp compress the valve and put the valve keepers back in place.
4. replace all valves the same way.
5. slide the camshaft back into place (make sure it is not back to front)
6. attach camshaft sprocket and bolt in place
7. place the correct rocker arms in the right place
8. place the rocker arm bolts in the correct place and make them finger tight
9. using a torque wrench tighten the rocker arm bolts to specifications in the order c3 e, c3 i, c2 i, c2 e, c4 e, c4 i, c1 i and c1 e
10. place the cylinder head back on the cylinder block (make sure the head gasket is in the right place and that the head is not back to front)
11. replace the head bolts.
12. using a torque wrench and manufacturers specifications torque the bolts in order c3 e, c3 i, c2 i, c2 e, c4 e, c4 i, c1 i and c1 e
13. you now need to set the clearance between the rocker arms and the valves
14. set cylinder 1 and 4 at top dead center. have cylinder 1 on the firing stroke to set the clearance for cylinder 4 and vice versa.
15. place a feeler gauge under the exhaust rocker arm and tighten screw so that the clearance is set to the manufactures specifications. do the same for the intake rocker arm.
16. set up for the next cylinder and repeat the steps.
17. place the rocker cover on top of the cylinder head. (make sure you have the rocker gasket in the right place)
18. place bolts in top and tighten  

remember if you need to replace any parts in the cylinder head take the part that needs replacing with you to make sure that what you are replacing it with is the right part, if in doubt don't waste a lot of money on a part that may or may not fit.