Automatic Centrifugal Timing Device

[Y-Blockhead]

Originally Posted by Bob Bidonde

Many many Model A'ers run hi-compression cylinder heads that do not require the amount of spark advance the stock head does. So the automatic advance gizmo may be the cause of spark knock if running with a hi-compression head.

That is exactly why some set the the initial timing at 4-5° ATDC. As I stated earlier, I run with the lever ~⅓ of the way down, timing set at 28° total. That way I can manually retard the timing if needed. I occasionally have to do this when pushing it on long uphills.

Originally Posted by Bob Bidonde

Also, running the automatic spark advance with hi-test gasoline may cause spark knock.

I don't believe this statement is correct unless you allow the Nu-Rex to advance the whole 30° and have a high compression head.

[29spcoupe]

I tried the automatic spark advance. Had trouble with the gimbal working properly. Send it back to New Rex for a replacement, second one had the same problem. I find that pretending it's not there and just advancing my spark to the halfway mark on the quadrant allows good timing. I guess I just got tired of removing the valve chamber cover and getting all that oil all over the floor.

[katy]

Originally Posted by 29spcoupe

I just got tired of removing the valve chamber cover and getting all that oil all over the floor.

That's what drip pans are for.

[Y-Blockhead]

Originally Posted by 29spcoupe

I tried the automatic spark advance. Had trouble with the gimbal working properly. Send it back to New Rex for a replacement, second one had the same problem. I find that pretending it's not there and just advancing my spark to the halfway mark on the quadrant allows good timing. I guess I just got tired of removing the valve chamber cover and getting all that oil all over the floor.

Did you ensure the hole in the head gasket that the distributor shaft passes thru is large enough? If the shaft drads on the gasket, the advancer will not work properly.I have never had an issue with my Nu-Rex advancer.

[29spcoupe]

Originally Posted by katy

That's what drip pans are for.

I have drip pans, no help! Hole in head gasket was fine. Just am not happy with the auto timing device.

[katy]

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29spcoupe, These are the type I talking about:
https://www.napaonline.com/en/p/BK_8114000