Distributor Play

[racertb]

First, let me know if this link to my clip works or not.  Second, if it works, does the play in my distributor look "normal" to you?

Not sure if this is right or not...thanks!


http://s947.photobucket.com/user/racertb/media/29Distributor_zpsc3f9a44d.mp4.html

[chetbrz]

You will always have some play in the rotor due to the backlash associated with the gear system.  When running there should be a consistent pressure on the gears which will place the rotor always in the same position within any given rotation.  I generally check for excessive play by just seeing how far I can turn the rotor left & right with the distributor stationary.  What I noticed with your video is that when turning clockwise the rotor moved clockwise and stopped but while you continued to turn clockwise it move another degree or two.  I thought this might be odd unless the distributor raised up while you were moving it.

These are just observations and I don't know if they have any significance.

[Old Man]

This is why engines have timing marks so a timing light can be used to set the firing point on the system while it's running and all the lash is taken up by the forward (backward?) torque of the gears etc. Setting the timing on a stopped engine is difficult because of the slop in the system. I've been known to put paint marks on an old engine on the crankshaft hub to duplicate modern timing marks. These are set mechanically to TDC or whatever your engine runs at ,8 before TDC etc. with out reference to the distributor. Then hook up a modern zenon timing light gun to an external 12 volt battery and don't forget to ground the 12 volt battery to the engine. Hook up the spark plug sensing wire lead from the gun to the #1 spark and start up the engine and idle it. Then watch the timing marks with the gun and rotate the distributor to align the marks. Voila the engine is set to it's real timing point with all it's own unique lash taken up. Don't foget to unhook any vacuum line to a vacuum advance system. (The early Plymouths did not have any.)   

[racertb]

Thanks for the replies...I just was wondering if it looked like there was too much play in the distributor.  When the distributor is out of the car, it feels solid and the shaft rotates freely; it doesn't feel or appear to be "bad".

[29UJohn]

The 29 distributor has a semi-automatic advance with weights and springs, so there will be movement.