Dwell setting
 

Does anybody know what the correct dwell setting should be for a Model A or Mode B engine.:confused:

Re: Dwell setting
 

do a forum search. there have been a few numbers quoted. most people set the gap with a feeler gauge not a dwell meter. I think the dwell will depend upon the cam you use, so there is no standard number.

Re: Dwell setting
 

As Jim said, this has been discussed in the past.. I can't remember the figures and I don't think I wrote them down.. The A and B cams would be different and I think the cams sold today are B.. One way to figure out the dwell number would be to set the points with a feeler strip and then run the engine with the dwell meter attached..

Re: Dwell setting
 

Interesting that dwell isnt used more on model As .

Typically dwell (coil saturation) is the point gap x 2. So a .020 gap would usually show approx 40 degrees on the dwell meter. It could proably run 45 degrees if needed.
The neat thing about dwell is its measured as a average of the four cylinders, so one cam could be a little off and still show a good ( average) dwell setting.

I would think no matter what cam the distributor had installed the dwell setting should be stable to run correctly......

Re: Dwell setting
 

I don't think Ford published any dwell specs until they put out the distributor machines and fixtures for the dual point early V8 distributors, so A and B can only be derived by experiment from gap spec...
Seems like they might be unusually easy to set this way...a spare cap with a small hole drilled in it to allow screwdriver to reach stationary point would allow setting dwell while running, like a '57-73 Chevy. Assuming tightening the clamp screw from snug to tight does not cause unpredictable motion, that is...
Chevys could be set to a surprising degree of dwell accuracy without even a gauge... drill used to be screw points toward closed to the point of severe misfire, then out I think 1/2 turn exactly put them on the money. The careful actually went out a full turn then back in 1/2 in order to end the operation tightening against the resistance...

Re: Dwell setting
 

There was a great article in one of the latest Model A magazines about dwell angle.
Get out your club books and read.

Re: Dwell setting
 

Re: Dwell setting
 

As a fellow A owner, I too have thought about fine tuning with a dwell meter. The only dwell meter I can find today are for 12 volt systems.
What do you use for a 6 volt positive ground system?? Would like to have the rpm feature as well. Thanks for your help to my question.

Re: Dwell setting
 

O.K. here is the big question for reading the dwell. How do you hook up a meter to read it? If I can use my analyzer to check dwell I may just do it. But how do I hook up the leads?

Mike

Re: Dwell setting
 

The November/December Restorer magizine has an in depth article on this subject. If you belong to an A club or know someone that does, they should have this magizine.

Re: Dwell setting
 

The dwell meter has 2 leads, black and red. Normally the red goes to the coil terminal that leads to the distributor points and the black to ground. On the Model A I think you need to reverse the connections, ie red to ground and black to the coil. The meter should work with the 6 volt system. Mine does.

You really don’t need to set Model A points with a dwell meter. Use a feeler gauge or a dial indicator. Practice setting the points with a feeler gauge and check your work with a dial indictor to see how accurate you are. The dial indicator also gives you the added benifit of seeing if your cam is within spec. Rotate the cam and check each lobes dial reading. First make sure your points are in alignment before setting. Also make sure the point surfaces are not damaged. A slight concave rounding of the surfaces is better than flat if you need to file them. Buy a point file and a point alignment tool.

Re: Dwell setting
 

Thank everybody for all the help. for Murphy J I did not know that dwell meters were voltage sensitive as the one I have has its own battery. It is an old radio shack kit I built when I was in H.S.