This method is handy when adjusting hydraulic lifters. For example, small
block Chevy's of yore (like my '69 Camaro) reguire adjustment while the
engine is running. You would back off the adjustment until you hear the
clicking sound of rocker arm on pushrod, then snug it down until the
clicking stopped, then tighten one more full turn a quarter turn at a time.
Each time you made a turn you could hear the engine protest briefly because
the valve wouldn't close until the lifter compensated for the new
adjustment.
There is no "clearance" per se when using hydraulic lifters as there is no
gap to measure with a feeler gauge.
They do make clips that attach to the rocker arm which serve as a feeble
attempt to prevent oil from spurting all over the place. I can see where
the modifed valve cover would be a handy way to further minimize the oil
from spreading.
Jim Leavitt (Sanford, Fl.)
'59 TR3A, since 1976
'69 Camaro since 1976
>An old hot-rod trick which I will do someday: Get an old valve cover and
>cut out the middle. Remove the stock cover and replace it with the cut-out
>cover. Start the engine and adjust the valves with the engine running. The
>cut-out cover will keep oil from running all over everything.
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While I could see this technique on an engine that the valves are adjusted
by a nut on the pedestal or other adjustment NOT associated directly with
the rocker arm, I am at a loss to visualize the procedure on a pushrod
Triumph engine. I can just see the feeler gauge flailing wildly around
whilst one vainly attempts to grasp the lock nut, at the same time trying,
without success, to turn the adjusting screw as the rocker jumps rapidly up
and down around a quarter of an inch or so every couple of seconds. (Sorry
I couldn't resist, and I am not making fun of anyone posting such examples,
this just triggered my memory of recent posts on this subject) Besides,
what's the advantage? If you have a set of cold clearances its MUCH easier
to set them at leisure. I have ALWAYS found it a pain (literally) to have
to adjust valves on a hot engine when required (MY Ford with rockers
similar to Triumph comes to mind). There is really NO advantage to a hot
setting. The expansion can be accurately determined with the expansion
rates of various metals known for some years now, and clearances can (and
many times are) given as cold allowing a much more pleasant valve adjusting
experience!
Barry Schwartz (San Diego) bschwart@pacbell.net
72 V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire
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