Jump to content

pjheys

Forum User
  • Posts

    1
  • Joined

  • Last visited

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

pjheys's Achievements

Newbie

Newbie (1/14)

0

Reputation

  1. pjheys

    Cam Timing

    Hi Angelfire, i am new on this forum but I have recently done the Cam timing on my Spitfire mk4 with a standard stock cam, I keep seeing the confusing information which is very complicated and it relly does not have to be, if you have the standard stock cam (ONLY STOCK STANDARD) the following procedure will check if your timing is out. You can does this with only the rocker cover removed however it will be difficult to rotate the crank nut but not impossible. Step 1 - Rotate the cam until valve 8 (one nearest to the car windscreen) is fully open (other terms like as reached its highest point have been used). I carefully watched the valve stem (long rod) at the back of the valve goes no higher, take your time with this and make sure you have it right. Valve 1 is now closed to test this if you can slide the valve from side to side easily and rotate the valve stem the valve is closed. Now adjust the gap or valve clearance to 0.40. Step 2 - Now do the same with valve 7 and adjust valve 2 to 0.40. Step 3 - Now from there you should not have to turn the cam far to get the point of balance, with your feeler gauge you are now going to time the cam and get valve 1 & 2 clearance exactly equal. To begin with I closely look at the gaps between 1 & 2 valve to see if there were similar I used a magnifying glass to get a close up view, I had to move the cam (very slowly) clockwise & anti clockwise to get the gap somewhere near. With my feeler gauge I think I used 0.10 thickness (I am sure the thickness is not critical, the idea is to find the point of balance) to get the gap exactly equal. This took me quite a while although the gap was similar the drag on the feeler gauge was not quite the same, don’t be happy with just being close get it perfect. Once perfect I used my feeler gauge with a 0.09 thickness to check the point of balance for both valves 1 & 2 with this thickness you should be able to place in the clearance with very little drag and it should feel the same for both valves. Now with a 0.11 thickness feeler gauge you should not be able to insert between both valves. This is a good way of checking the valve clearance is the same. Step 4 - Now look at the timing marks on your crank the mark on the pulley wheel should be exactly at TDC Another way of checking without doing the above is to place the crank at TDC and valves 7 & 8 should be exactly the same one about to close & one about to open they should look equal and you should not be able to rotate the valve stem, if either is not right timing is out. Let me know if you need the full steps to replace chain and gears. Hope this helps
×
×
  • Create New...