cylinder head rebuild. lapping valves and vacuum testing heads
so done a lot of work on the heads. the camshaft bearing bridge was already of. So only the valves springs and retainers holing the valves in place. Also the heads where pretty dirty. Lot of carbon and grease build up.
I removed the valve springs so i can remove the springs. i marked them all on the top of the valve shaft, so i can place them back in the same place. This is pretty important because there is always difference in the seats and the valve surface. So best is to place them in the same position so you have the biggest chance of have a good seal.
The intake valves where only a little greasy. i soaked then in ammonia for a few hrs and them cleaned them with some paper. The exhaust valves had some very big carbon build up that i remove with a brass bruss on the drill bit to grind of. The valves are very hard and the brass is much softer so it will not damage the valves.
After also cleaning the heads with soaking in ammonia for 24hrs and pressure washing them the came out pretty clean. After this is place the valves and relapping them with the small grind grit to get a good sealing surface.
After this i made a test tool with a vacuum meter and a steel plate with a rubber piece on i can pull the chamber under vacuum to check it if is sealing good.
on 1 cylinder i had to relap the exhaust valves again because it was not pulling the full vacuum. Also to remember is that the exhaust chambers are all connected because of the EGR system. so to test the vacuum all the holes need to be blocked off with rubber pieces. But it worked out pretty good.
Also i have send of the Engine block to be resurfaced on the top see the picture’s below why
if there are any questions just ask