brucep

A paper written by Duke Williams that can be found on BarryK's website says the B26 Vacuum Advance Canister is more appropriate for an L-79 than the factory recommended B28. My L-79 is currently set up with an B28. If I switched to a B26 I wonder what advantage or differences in performance or tuning options I would have.

Here is a link to the paper:

http://www.lbfun.com/warehouse/tech_...ance_Specs.pdf


Thanks.

Gary's '66

I'm no expert, but having dealt with MANY vac canisters with my L-79 I can tell you what I've encountered.

To start, you need to determine how much vacuum your motor is pulling at idle (assuming timing, carb, etc. is set proper) and that will give an idea of what canister to employ.

Another thing that will affect vac adv. can is whether or not the points plate bushing is there and, even then, sometimes the slot it rides in needs tweaking.

Lastly, before I install ANY aftermarket can I always test it using a Mightyvac to determine just how accurate it is. Many that I've tested where WAY off.
Hope this helps.

plaidside

If you have low vacuum at idle, below 13" then you need the B-28 can. But it might cause some pinging due to the advance added at low vacuum.
If you have at least 14-15" vacuum at idle then you can use the B-26.
This will remove the advance plugged in by the can sooner and should reduce pinging issues.
Joe

Ironcross

Why worry, your at full advance immediately.......

Boyan

I have not tried it on an L79, but I can tell you Duke is right on. He told me to put a B26 on my 63 L76 when I had problems with it running after a rebuild. His advice made it run perfectly. Just follow what he wrote.

Boyan

brucep

Thanks all. My L-79 idles at 13-13.5. Mightyvac testing of 2 new B26 cans shows their advance to be all in at 13. Following Dukes rule that the can you use should be all in at at least 2 inches below idle vac, it looks like I should be sticking with the factory recommended B28.