[TheForge] Re: Krause/Nazel type air hammer

[Mike Spencer]

>  We used a regular valve seating tool - it was hand cranked and
> produced a reciprocating motion on the shaft which had a suction cup
> on the end to stick on the valve.

I once had a B&D electric valve lapping tool, probably pre-WW II
vintage.  Given to me by a mechanic who was 80 yrs old in ca. 1968 and
still working.  It looked kinda like an ordinary electric drill and
produced a rather slow oscillating motion on the output shaft.  He
said you attached it to the valve stem (with the valve in place in the
block or head), applied lapping compound to the mating surface and ran
it a bit.  It was missing the neccessary widgets to attach it to
valves -- presumably different ones for flathead and OHV
configurations -- so I eventually traded it off for something or
other.

The only time I've lapped (automotive-type poppet) valves was in my
tiller where there is no seat insert, just bare cast iron (Clinton
engine.)  Valve grinding tools even 30 years ago made a nice match on
steel insert seats and they're too hard to make lapping much use
anyhow.  I vaguely recall that a friend who built formula Ford racing
engines in the 70s lapped all the valves but I think it may have been
mainly so that he could tell the owners that he'd done it.

- Mike

-- 
Michael Spencer                  Nova Scotia, Canada 
                                 
mspencer@tallships.ca            
http://home.tallships.ca/mspencer/