Re: Valve Grinding and Guides

Posted by H. L. Chauvin on Sep. 17, 1998 at 21:02:26

In Reply to: Valve Grinding and Guides
posted by Glenn Spyksma on Sep. 17, 1998 at 19:36:12

: I am currently rebuilding model A engine --- havereciprocating valve grinder.Jim Schild describes that the valves should have been numbered by the orignial valve grinder.
: If I am installing new guides do they need to be fitted to the valves?Is there any work required for the valve guides?Or is Jim saying that since each guide alignemnt is slightly different, once the seat is cut, the guide and valve should be numbered to the bore?
: Thanks for your help, all advice is welcome.
: Glenn
: Hi Glenn,
Its a good idea to separate all valves and all pairs of valve guides, both new and re-used, and number all 1 thru 8 from front to back of engine. A wood plank with 8 numbered holes for valves and 8 numbered holes for valve guides is handy. Always keep new and re-used valve guides in original pairs.Re-used valves will seat better when lapped in original seats, and re-used valves fit re-used guides better when re-instaled in original pairs of guides.New valves can be installed in any new guide; however, once lapped, number both valves and matched pairs of guides.Guides are not normally fitted to valves; however prior to laping, some new valves may fit better in certain new guides and one may want to try matching new valves to new guides."K. R. Wilson" valve guide tool is far superior to the bent rod tool.A 20 gauge shotgun bore brush is excellent for cleaning carbon out of block holes prior to installing valve guides.Valves and valveguides wear after many miles;usually a good idea to check valves and guides at each new ring job -- buy 1 new valve guide and 1 new valve, shake new and used valves sideways in new and used guides to compare new parts to used parts. To prevent premature engine wear, clean all lapping compound from engine thoroughly after lapping.Install valve springs last. Always used 0.011 intake clearance, and 0.013" exhaust; however, "The Restorer", Vol. 42, Issue 1, May/June 1997, page 35 has excellent article on valve timing, (indexing), being more important than tappet clearance for balanced engine.
Hope this helps.
Best Wishes,
H. L. Chauvin