Wd and WD45 dwell angle
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Topic: Wd and WD45 dwell angle
Posted By: Gatz in NE
Subject: Wd and WD45 dwell angle
Date Posted: 15 Jan 2010 at 10:43am
| Anyone know that the Dwell angle would be for a WD or WD45 ? |
Replies:
Posted By: LarryWC In
Date Posted: 15 Jan 2010 at 12:35pm
|
Gatz,,just off the top of my head I want to say 4 degrees?,,,I'm not at home right now,but have this information available,,I will check and verify!!! ------------- www.allischalmersmuseum.com |
Posted By: LarryWC In
Date Posted: 15 Jan 2010 at 2:58pm
OK,,Here ya go Gatz!,,I was Close,,,,,this is what the IT manuals says,,,,
 ------------- www.allischalmersmuseum.com |
Posted By: Gatz in NE
Date Posted: 15 Jan 2010 at 6:01pm
|
Larry,
Guess I'm a little dense.... how is the dwell angle determined from the data given ?
|
Posted By: orangereborn
Date Posted: 15 Jan 2010 at 6:21pm
| I think it should be more like 32-34? It represents the degrees of rotation of the dist cam the points are closed between cylinder firings. If my memory has failed, someone correct me....Dale |
Posted By: Brian Jasper co. Ia
Date Posted: 15 Jan 2010 at 6:42pm
|
Cam angle is also known as dwell. Dwell is the number of degrees of distributor rotation from the time the points close to the time the points open. In reality, it's actually a measure of time. 4 degrees of dwell would be would be a very small amount of distributor rotation from points close to points open and it would be unlikely the engine would run. Typical dwell is in the 25 to 30 degrees range. You can measure dwell on an electronic ignition. If I remember correctly, dwell on an HEI system is fixed at 40 degrees. Dwell on points is measured at idle speed because it will drop as the engine speed increases. Having a fixed dwell is one of the advantages of electronic ignition. The higher the dwell time, the higher the coil saturation. Higher coil saturation combined with a faster primary cut off makes a stronger spark.
------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: Brian G. NY
Date Posted: 15 Jan 2010 at 8:28pm
| Hey Larry, Where did you get this nice little spec sheet? I couldn't find anything in either the WD/WD-45 or D-17 manuals about dwell and here you not only have the dwell (25-34 deg.) but a whole lot more info. |
Posted By: Gerald J.
Date Posted: 15 Jan 2010 at 8:57pm
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Measuring dwell is an indirect way of setting the point gap. Or setting point gap is an indirect way of setting dwell. Changing the point gap for either test changes the ignition timing. Setting by dwell was a GM thing for when they built the distributor so you could hardly get to it to set the point gap like when the distributor was at the back of a V-8 block practically under the cowl. Typical dwell is about 50% of the time. So for firing every 90 degress of the distributor rotation, dwell can be as long as 45 degrees to be close half the time. One thing about checking dwell is in most distributors other than those GM with the little window to stick the allen wrench through to set the point gap, you can not set the dwell while running. So you set the point gap by the point gap specs and you can check the dwell with the engine running to see if its in the ball park. Another thing you can see on the dwell meter is if it bounces about a lot you have a hint that the distributor shaft is wobbling in a loose bearing giving both random dwell, but also random ignition timing. That can be a handy diagnostic. Gerald J. |
Posted By: LarryWC In
Date Posted: 18 Jan 2010 at 8:48am
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If you carefully read on the sheet I posted,you will see right before the section on GENERATORS, it tells you for the type of distributer the WD and WD45 has (1111745) "Cam angle degrees" 25-34. This information came out of a IT manual I got at Rural King ------------- www.allischalmersmuseum.com |