Re: Ignition Knock
Posted by Tim Cole On 2022/10/12 9:44:28
Here are some pictures. The first picture is of a dwell meter. Hook the red lead to the positive post of the coil and the black lead to the negative, start the engine, and read the meter. The rpm switch is there as an aid.
The second picture shows a reading on a meter.
Suppose you took your car to someone you know and he says: " I don't have one of those, but I do have a multi-meter for modern cars." If he hooks his meter up the same way and switches it to Duty Cycle he will get the percentage of time the points are closed - Dwelling. Multiply that percentage by 360 and divide by eight and you have the dwell angle. Of course you need only check that Duty Cycle remains relatively stable when you raise the RPM to determine if the distributor is worn.
I have a KAL 3000 multi-meter which has a dwell setting and can do the Caddy 12 and 16 as well as Packards. They show up on junk bay and are cheap because nobody wants them. KAL equipment was a competitor to SUN.
Attached is a picture of a distributor tester in action. The rebuilder will expect to see the lights remaining in position and not jumping around as RPM is increased. The timing advance mechanisms are checked by reading the position of the lights as RPM is increased. I love those old machines and those big engine analyzers. One time I was working on a car and the owner got pissed off that I sent the distributor for repair. I didn't hear anymore complaining when the motor would start in 1/8 turn when it came back.
Attach file:
Dwell Meter.jpg (134.19 KB)
DwellTachScale.jpg (39.01 KB)
Distributor machine.jpg (33.07 KB)
The second picture shows a reading on a meter.
Suppose you took your car to someone you know and he says: " I don't have one of those, but I do have a multi-meter for modern cars." If he hooks his meter up the same way and switches it to Duty Cycle he will get the percentage of time the points are closed - Dwelling. Multiply that percentage by 360 and divide by eight and you have the dwell angle. Of course you need only check that Duty Cycle remains relatively stable when you raise the RPM to determine if the distributor is worn.
I have a KAL 3000 multi-meter which has a dwell setting and can do the Caddy 12 and 16 as well as Packards. They show up on junk bay and are cheap because nobody wants them. KAL equipment was a competitor to SUN.
Attached is a picture of a distributor tester in action. The rebuilder will expect to see the lights remaining in position and not jumping around as RPM is increased. The timing advance mechanisms are checked by reading the position of the lights as RPM is increased. I love those old machines and those big engine analyzers. One time I was working on a car and the owner got pissed off that I sent the distributor for repair. I didn't hear anymore complaining when the motor would start in 1/8 turn when it came back.
Attach file:
Dwell Meter.jpg (134.19 KB)
DwellTachScale.jpg (39.01 KB) Distributor machine.jpg (33.07 KB)This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=249165