New-York tribune., 1918-08-18
Grind Valves Only
When You re Sure
They Need 1t
By ri. Clifford Brokaw

Don't grind your valves-not unless
necessary. Don't be forever fussing
around the motors nostrils any more
than you would about your own. Don't
imagine that every little trouble has
ies orlgln in leaky valves. 1t may be.
but you should be sure about it before
spending an hour or two that way.
There is a certain class of drivers
who, whenever the engine does not
perform up to standard. adjust the
carburctor. Another class files a dol
lars worth Of metal from the inter
rupter points. Still another always
wants to grind valves. There is moth
ing which is cure all for engine
maladies.
have friend who, after working
over his balky moto-. for an hour
finally took the "pencil" out of the
magnetic and wiped off the grease that
had collected on it. The engine then
started without difficulty. He now per
forms this operation to cure every
thlng from boiling radiator to a fiat
tire. TO date | have been unable. to
convince him that cleaning the "pen
~ WIZ h'l make tne engine run If
there IS no GAsolere in the tank.
Leaving Inlet Valves Alone
The number Of times valves need to
he ground varies on different curs-.
varies widely. But once q wear is
more than enough for the inlet valve.
lhls valve remains closed when the
combustion takes place in the cylinder
and during the exhaust, and when it is
open nothing but fresh gas passes
through it. Therefore it retains
good seat long and it is a mistake to
grind in the inlet valve everv time
the exhaust valve is doctored. Ger
talnly so on the idea that it is going
to give trouble sooner or later, and it
IS well to forestall trouble That is
fallacious reasoning.
1t the cylinder misires one of the
first things to do is TO test the COM
preston with the starting crank, to
determine il lack of compression
might be the cause CT the trouble. II
the compression is poor the exhaust
valve usually may be suspected To
determine this fault it is necessary to
remove the waive from the engine and
examine the seat. II particles of car
bon or rough places are found, it is
t'me to act. Pieces Of carbon may be
scraped oft with a knife and this alone
Wall remedy the difficulty.
However, to make sure of the seat
~ IS well 7" use some very fine grind
ing compound or -four emery mixed
with oil, and just rouch up the seat
on both valve and seat. TO grind
iurther Is useless and harmful. Coarse
grinding compound or TOO much grind
ing or improper grinding will cut
rings IN the valve and destroy the seat
Don't Grind Too Deep
have seen cases where valves have
Deen ground so deep in The cnssiny
mat the seat was at the bottom of a
we'll and when the valve was pushed
open there was very little space for
the passage of exhaust gases. A little
more grinding would have worn
through the casting, leaving no seat
at all. 'o"'
When the valves have deep grooves
ground in them they must be swung
IN lathe and faced off or new ones
procured To prevent this condition
use very fine grinding compound, al
though 1T may he-a little slower than
coarse Rotate the valve back and
forth on ITS seat. using little or no
pressure. Every few twists the valve
'o",H pe ~ Ceu Tree OF the seat and
should get about one-quarter turn.
If the valve seats in the cylinder care
should be taken to plug up all open
ings leading to the cylinder, so that no
grinding compound may work inside.
Care should also he taken to wipe ali
OF the compound out when the grind
ing is completed. Otherwise it will
Keep on grinding and wear out the
cylinder wallis.
Sometimes the valves are located
under the head Of the cylinder block
and !, is necessary to remove the TOP
IN other cases they are overhead in
removable cages Usually the valve s
under cap on the side Of the cylinder.
so that the individual valve NAV be re.
moved as desired.
Care About Push Rod Clearance
1t is well to check up the push rod
clearance before and after valve