The following quoted post reminds me, if the person who asked the
question originally (about a GMC motor) could find the numbers on his
distributor plate, I may be able to get the dwell spec. My friend down
the road has my old Motor Manual, and instead of showing dwell and point
gap by engine, it seems to go by distributor number. Sounds like a pain
to me, but I agree that you probably can't calculate the dwell from the
point gap alone. Send me the numbers and I'll call him back up and see
what he can find.
"Hi All
Don't know if this is any great help but My motors manual for Chevrolet
under Distributor Specifications show for Point Gaps of .022" the Cam.
Angle
Degrees or Dwell should be 31 - 37 degrees. For Point Gaps of .019" -
.016"
the Dwell should be 38 - 45 degrees. I have found that with the
distributors on the 6 cylinders the dwell meter bounces a lot while
trying
to set the points. My resolve to this is to put a light across the
points
rotate the crankshaft until the light goes out, points open mark a
reference
point on the crank pulley and block then continue to rotate the crank
until
the light comes back on, points close, then make another mark on the
crank
pulley adjacent to the mark on the block. move the crank pulley back
until
the mid point of the marks on the crank pulley lines up with the
reference
mark on the block. This will put the point at their maximum open
position.
Then simply set the gap using .019" for new and .016" for used. If you
have
a good feel with your feeler gauge you can be dead on. Once you are
happy
with your adjustment ensure the lock down screw is tight, reinstall the
rotor and cap. Hook up your dwell meter and start up the engine. You
should be well within the range specified above.
Good Luck
Mac"
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|