If anybody is using the ÔÇ£123ignitionÔÇØ, which advance curve out of the 16 available did you find to work best? I installed one on my 67 roadster.

Merry Christmas Everyone!

Submitted by NC13-48859 on Tue, 01/31/2012 - 17:07

Peter, I have model 123/JAG-6-R-V. Based on the informative postings on the 123ignition.nl forum it is unadvisable to run the XK engine with more than a maximum of 34 degrees advance. This agrees with your recommendation. Therefore, on my model, I am limited to only 3 advance curves out of the 16. Chuck, as I understand it, all 16 curves on your model 123GB 6-R-V have a max of 34 degrees. You have many more choices.

To answer my own question, I have found curve #2 to work best. It is 12 deg. advance @500-1200 rpm, 21.8 deg. advance @2000 rpm, 34 max deg. advance @3000 rpm. starting with a static figure of 10 deg. I have tested this setting on the expressway up to 4300 rpm in 4th gear (100 mph). Pinned into my seat it was still eager to go faster. I held this speed for a while carefully listening to engine feedback. Not wanting to press my luck with the authorities, I ended my test with the knowledge that the engine and car ran great.

Submitted by roman0213@cs.com on Tue, 01/24/2012 - 17:36

Miklos,

I bought a 123 distributor.. didn't install... But it is the GB-6 123GB-6-R-V.... In a conversation with a Jag mechanic who has used the 123 .. he suggested the "1" setting... don't know from experience as I went with pertronic...

Good luck, I'd be interested in your final setting!

Cheers...

Chuck

Submitted by NE40-48370 on Mon, 01/02/2012 - 15:09

Which 123? There's a Jag version and general 6-cyl version. The curves are different because engines vary widely. It's a classic case of too much choice sometimes being a bad thing.

FWIW they are all fairly aggressive curves and I would make sure you at least don't end up with too much advance too soon, or at full advance. You need a strobe and start out with their static figure (10 degrees or zero depending on type IIRC). Don't be afraid to back off static to get you a safe full-advance figure at the end of your curve. Depending on your compression and fuel I would not go higher than 32-34 degrees on a long stroke two valve hemi, without full set-up facilities.