Topic: Engine Readings on '46 Deluxe


51woodie    -- 08-08-2018 @ 4:15 PM
  Finally got my car back together and certified/plated. I rebuilt the fuel pump, carb and distributer, as well as lube changes, brakes etc. Used elec. pump to prime then shut it off. Engine fired after a few turn and idled nicely. Checked the vacuum and dwell, with vac a steady 19" and dwell is 40 deg. (points set at .016", unit not set up on machine). I think my idle speed may be a bit high, but not being that familiar with the sound of a flathead idling, I'm not sure. I took it for a 30 mile run today, oil press 20 at idle/50 at speed, temp +/- 180 deg. No "ping' on hard acceleration from 30 mph in third gear. Comments on the vac. dwell numbers?


cliftford    -- 08-08-2018 @ 9:09 PM
  Ford specs call for .014 to.016 on points, and 36 degrees dwell,so you are very close so I would leave it is, the rubbing blocks on the points will wear some, decreasing dwell. the vacuum reading sounds normal.


cliftford    -- 08-08-2018 @ 9:09 PM
  Ford specs call for .014 to.016 on points, and 36 degrees dwell,so you are very close so I would leave it is, the rubbing blocks on the points will wear some, decreasing dwell. the vacuum reading sounds normal.


cliftford    -- 08-08-2018 @ 9:09 PM
  Ford specs call for .014 to.016 on points, and 36 degrees dwell,so you are very close so I would leave it is, the rubbing blocks on the points will wear some, decreasing dwell. the vacuum reading sounds normal.


JayChicago    -- 08-09-2018 @ 7:38 AM
  As the rubbing block wears, doesn't that reduce the duration of points-open, and therefore increase the dwell? But I know that might be too simple, because we are talking about a two points distributor with overlapping closed/open points, and I still don't understand how those two points sets work together.


cliftford    -- 08-09-2018 @ 7:43 AM
  I stand corrected. I guess I was thinking backwards.To put it simply, the open time of the two sets of points overlap, increasing the dwell and allowing better coil saturation. Either pair can open and close the circuit. They are in parallel.

This message was edited by cliftford on 8-9-18 @ 8:33 AM


TomO    -- 08-10-2018 @ 7:12 AM
  Total dwell is not a good indicator of correct adjustment of the points on the dual point distributor.

The drivers side set of points make the circuit and the passenger side points break the circuit. The passenger side points determine the timing of the spark. To have correct adjustment of the points, both sets should be set for correct timing and this will result in a total dwell of 36 degrees and initial timing of 4 degrees before top dead center.

You should have the distributor set up on a distributor test machine by a competent operator as this will check for point bounce and correct timing of each set of points. Next best is a timing fixture and the last thing that I would try is the ruler method.

Incorrect timing will lead to starting difficulties and overheating, although it is not the primary cause of thse problems.

Tom


sarahcecelia    -- 08-11-2018 @ 10:05 AM
  When igniton point rubbing blocks wear, Dwell INCREASES!! Dwell, is the "duration of the time the points are CLOSED!!" It is fairly important because if it is to low a reading, the coil is not fully saturating, which means it gives a weaker spark to the plugs.

Regards, Steve Lee


sarahcecelia    -- 08-11-2018 @ 10:15 AM
  Dual points can be set by blocking one set one set with a business card, cranking the car and reading the unblocked set. Then, reverse the proceedure and read the other set. I set my '57 Corvette (which was manufactured with a dual point distributor) points that way, whenever I install nwe ignition points.

Regards, Steve Lee


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