The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: huddie on 23.02. 2010 15:08

Title: ignition timing
Post by: huddie on 23.02. 2010 15:08
Hi you guys, I just about finished the rebuild on my 57 Flash. Every thing is set up as std. When timing it with the head off it's relatively easy, but what's the preferred method for determining the piston position as I want to check the timing again now it's been run for a few minutes. When set it up before (basket case) just to get it going I put a soft rod down the plug hole, marked off tdc as close as I could get it. I then marked it again 11/32 above that on the rod and used that as a guide. Now as the rod is not rising vertically this method is likely to be out a bit.Coupled this with a fag paper to set the points. After the great expense of a full rebuild I would like to do it a bit more scientifically. I have read the posts refering to the use of a magneto timer/buzzer rather than the fag paper but I couldn't find anything about setting the btdc position.
Hope you can help, Regards for now Huddie
Title: Re: ignition timing
Post by: RichardL on 23.02. 2010 16:11

There are a lot of ways out there, some more technical than others. All you have to do is see Richard's (Orabanda) approach to know it can be done with a timing disk and optimized on a dyno. Nevertheless, for the likes of me, the one I show at the attached link seemed to do a good job. The straws are straight up and down and actually sit on the flat portion of my 9:1 piston, not the dome.

Richard L.,156.msg5969.html#msg5969
Title: Re: ignition timing
Post by: huddie on 23.02. 2010 16:38
Hi Manosound, Many thanks for that. All the options I tried in the search box didn't pick up this topic!  Plenty of useful advice there.
Regards for now Huddie