Valve clearance shims?
Moderator: RichardW
what my workshop landlord who dose cylinder haed work for a liveing uses two lengths of steel about 10/12''long by 2'' by1/4'' with a tapered matal post aprox 10'' one fixed to each bar at right angles so the post sticks up wards,put one post into a bolt hole at oposite ends of head and bongo you have pair of head stands regards malcolm
Lapping is the good old practice of valve grinding to get a good seal. Its done using carborundum paste and the idea is that you hold the valve head with a rubber sucker on the end of a wooden handle, put a dab of paste on the seat and rotate the vave against the seat forward and backwards. Getting a good seat is rather more difficult than it sounds as the things tend to groove and generally after about 5 minutes you discover pits that are too difficult to get out while getting a good seal. (Excessive grinding tends to produce curved seats or seats that are too wide or have rings.)
The best solution is to have the valves re-faced (if possible) on a special grinding machine and the seats cut with a dedicated cutter (which is in fact generally a hand held cutter on a suitable shaft that fits the guide) The valves should then be lightly lapped to get a perfect long lasting seat.
Manufacturers actually cut the valve seat valve face at slightly different angles so that lapping isn't required.
jeremy
The best solution is to have the valves re-faced (if possible) on a special grinding machine and the seats cut with a dedicated cutter (which is in fact generally a hand held cutter on a suitable shaft that fits the guide) The valves should then be lightly lapped to get a perfect long lasting seat.
Manufacturers actually cut the valve seat valve face at slightly different angles so that lapping isn't required.
jeremy
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with crank set with pin in flywheel through crank case behind starter motor,so you know its in right place,take pin out rotate crank a quarter of a turn anti clockwise when faceing crank pully,then once you have reset cam after you have finnished checking shims,just turn crank clockwise by quarter of a turn till pin goes into flywheel regards malcolm
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- Posts: 138
- Joined: 21 Jun 2005, 03:17
- Location: Scotland
- My Cars:
- x 2
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- Posts: 138
- Joined: 21 Jun 2005, 03:17
- Location: Scotland
- My Cars:
- x 2
-
- Posts: 138
- Joined: 21 Jun 2005, 03:17
- Location: Scotland
- My Cars:
- x 2