[TR] TR4a ignition advance

[spamiam at comcast.net]

I saw the large listing of the Lucas dizzies by Chichak.  It looks as if he had access to some Lucas documents for this info.   It looks pretty reliable to me.

It indicates 4 RPM data.

225 rpm = zero degrees
350 rpm = 1 degree
600 rpm = 6 degrees
1200 rpm = 10 degrees

These seem to be referring to distributor RPM and degrees.  I now am pretty sure that the highest RPM listed represents "full" advance, too.

Also, I think that at the low RPM levels, the exact advance was pretty variable in these units, and this is why they specify static timing rather than strobe timing.  

These numbers seem to make more sense than the zero at 500-1000 rpm.

-Tony



-------------- Original message -------------- 
From: "Randall" <tr3driver at ca.rr.com> 

> 
> > BTW, 4 static + 6 vacuum + 22 mechanical = 30 total degrees, 
> > or so it would appear. 
> 
> Generally, when people talk of "total" advance, they do not include vacuum 
> advance. But you are quite right, it is possible to get that much, only not 
> with the throttle very far open. 
> 
> BTW, Chichak gives max advance for the 40795 as 10 degrees @ 1200 rpm. I 
> don't have any information of my own handy, but that would be the first 
> mistake in his database that I know of. 
> http://www.jcna.com/library/tech/tech0015.html 
> 
> Randall