Buick Valve Spring Change In-Car

by Mike Garrison



This engine is my 535 stage 2 TA Performance engine. I seemed to hit the rev
limiter at the last race and broke a spring. Its in a 70 GS 455 I have had
since 1977.

First you have to determine which side that has the broken spring. In this
case it should be obvious. Using a compression tester hose I attach air to
it and compress the cylinder so the valve wont go anywhere. If it falls into
the cylinder It will be a major operation to get it back where it belongs.
BE AWARE!! When you apply the air the engine can and mostly all the time
will rotate some. I took this apart but I took the #6 springs off to find no
issues. SO once I pulled the #4 spring off it was obvious I had the correct

Using a tool I bought from Charlie Evans I compress the spring down and then
using a magnetic screwdriver so I dont drop the keepers I remove them. Once
the keepers are off the spring is free to remove. Now would be a good time
to change the valve seal if it was damaged when the spring broke. (as mine
was). Once the seal is changed reinstall the replacement spring and compress
it down install the keepers and release. And there it is done. I like to
take the air off then run the valve down to make sure it runs up and down
freely. I use a wide bladed putty knife under the compressor tool.

At this point your ready to put the plug back in, install the rocker shaft
(and adjust them), valve cover and wires and fire it up its ready to go