[DeTomaso] More valvetrain for 6143

[jderyke at aol.com]

In a message dated 1/21/10 12:40:46 PM, guson at home.se writes:

> Are there single grove keepers that have the same diameter as the stock 
> multigroove keepers? I couldn't find any myself. The suggestions so far have 
> been using Boss retainers that supposedly have a smaller hole than the 
> stock retainers and would fit the commonly available keepers.
> 
All keepers for Ford 11/32" valve stems are about the same dia. The way 
multi-groove ones work is, the halves butt together slightly before clamping 
the valve stem. This lets the valve shift slightly and prolongs the life of a 
valve job. But because the stem is always a little loose, multi-groove 
keepers have unlocked at high rpms.... Single groove keepers don't butt together- 
if you look closely, there's a space between the two halves of a single 
groove pair, very tightly clamping the stem in place. 
Boss keepers are single groove 7 degree, made from forgings rather than 
weaker stampings. 'Boss' keepers drop right into stock 7 degree steel retainer 
washers. 10 degree racing keepers won't fit stock 7 degree retainer washers, 
and there are special single-groove keepers (both 7 & 10 degree) of 
different heights for changing valvetrain geometry in certain cases without 
machining. FWIW- J DeRyke