Deejay, Bet your'e using 5w30 engine oil, Move up to 5w40 fully synthetic and that tends to quieten the tappets down. These engine's were made along side the diesel variant and tolerances became generic compromises. Ford would tell you they should be run using 5W30 but again this is a cost narrowing issue and that oil best suits a turbo optioned engine. Also try millars nanotec + version its the oil the race boys use as the price is extremely good, comparable in fact to any premium oil!
Keith, don't worry about special tools, Pull the plugs and rotate the engine by hand. Measure the clearances for all the followers and write them down. Under that write what the clearances should be. then remove the cam shaft in question and read from the follower what the size is. You can now add or subtract the difference from what the gap should be to what it is actually measuring (to or from) on the current follower. To remove the followers use a magnet, The size is marked on the follower. Inspect the removed followers and ascertain where the wear is, ie. cam lobe or follower, it's usually the bucket tappet as they are designed to wear first. You will need to mic the bucket tappet in order to see how much wear has taken place.
Here's an example of how you work out which new size bucket tappet you will need on a particular valve.
A) desired tappet clearance =0.30mm manufacturers stated figure
B) measured clearance =0.36mm what you measured when checking the clearance
C) tappet thickness found =2.19mm thickness of internal to external tapped size
D) new thickness required =C+B-A =2.25mm This measuring method takes into account all wear issues with that particular valve bucket tappet.
Oh, one last thing, you'll get advice saying you can swap bucket tappets around to suit a different position if the size is suitable, Don't do this as the wear pattern on each tappet will be different and it will promote premature wear and you'll be doing it again very soon!
