Setting points gap?
Thread Starter
Racer
Joined: Dec 2002
Posts: 421
Likes: 2
From: Long Grove, IL
Setting points gap?
I have installed a new set of points in the distributor on my '69 and thought they would have to be gapped prior to trying to start the car. The FSM seems to indicate that on 8 cylinder engines the points are 'pre adjusted' and the only setting is dwell. Is this correct? It sounds too good to be true.
Thanks
Jay
Thanks
Jay
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Gap & dwell are exactly the same thing.
Setting the gap refers to the mechanical method (the original method) and setting dwell is the contemporary (well.... 40 years old) electronic method.
Dwell is the number of degrees the points remain CLOSED. This is the time when current is flowing through the coils primary winding to build up a magnetic field. When the points open, primary winding current stops, the field collapses and induces a voltage/current in the secondary winding which fires your coil (plugs).
Dwell is an "avarage " reading... not an absolute.
You set point gap with the points rubbing block on the highest point of the cam, engine stopped. Either bump the starter, or use a socket on the crank to get the rubbing block on a peak. I just loosen the distriibutor and rotate it. A feeler gage is inserted between the points, and the point gap is adjusted so that the gage just slips snugly between the points... not too tight, not too loose. When the rubbing block rides down to the flat, the points are closed.... where dwell is measured using a dwell meter.... engine running.
Either way... you are setting the same thing.
Don't forget to check/reset the timing after you install a new set of points. Altering the point gap setting alters initial timing, whether you loosen the distributor or not.
Setting the gap refers to the mechanical method (the original method) and setting dwell is the contemporary (well.... 40 years old) electronic method.
Dwell is the number of degrees the points remain CLOSED. This is the time when current is flowing through the coils primary winding to build up a magnetic field. When the points open, primary winding current stops, the field collapses and induces a voltage/current in the secondary winding which fires your coil (plugs).
Dwell is an "avarage " reading... not an absolute.
You set point gap with the points rubbing block on the highest point of the cam, engine stopped. Either bump the starter, or use a socket on the crank to get the rubbing block on a peak. I just loosen the distriibutor and rotate it. A feeler gage is inserted between the points, and the point gap is adjusted so that the gage just slips snugly between the points... not too tight, not too loose. When the rubbing block rides down to the flat, the points are closed.... where dwell is measured using a dwell meter.... engine running.
Either way... you are setting the same thing.
Don't forget to check/reset the timing after you install a new set of points. Altering the point gap setting alters initial timing, whether you loosen the distributor or not.
