Performance cammed engines want a performance ignition timing advance curve. More initial timing, a specific amount of mechanical advance, and a LIMITED amount of vacuum advance. Especially with high compression engines it is important to tune your advance curve to avoid detonation. Everyday Performance LLC has produced a set of Vacuum advance limiter bushings to make reducing and tuning your vacuum advance an easy task. No more drill bits, clamps, epoxies, welding......HASSLE. Simply install the color coded limiter bushing of your choice onto the vacuum advance shaft as shown, and install your vacuum advance can onto your distributor. This limited production run has 4 color coded sizes (installed on B1 can with 16deg available advance) (The vacuum can is limited to the degrees listed) black = 5deg Silver = 7deg Gold = 9deg Red = 11deg Now it is easy to tune your maximum vacuum advance and avoid detonation/pinging at cruise. Get back your fuel mileage and throttle response. Each kit of 4 color coded bushings costs $25 shipped in the USA Limited Quantities available in the web store: http://everyday-performance.com/sto...nce-bushing-kit/p/139273257/category=21548473
EDIT: here is the link to my web store listing http://everyday-performance.com/sto...nce-bushing-kit/p/139273257/category=21548473
They are based on the B1 and B22 cans with 16 degrees advance stock. But yes they will fit a B22 or most any other can with a shaft that is 5/32" It bears mentioning that they can be made to any size. I simply picked 4 sizes I thought most useful.
Just tried one out on a crane adjustable vacuum advance can and, since the crane unit has more travel than a stock can, the black limiter put me at 6* of vacuum advance. The silver or gold should put me right where I want to be. It is nice to have the piece of mind that my vacuum advance will be firmly limited. I much prefer this versus having to drill and tap a hole to relocate the crane limiting cam. The screw for that cam is also difficult to get to without using a handpump to move the advance plate. Thanks for another quality part Ken!
This is good info. I currently use the Accel adjustable Vacuum advance unit (Allen key in the vacuum slot) which works well for me but it would be nice to be able to use several of the factory advance canisters I have laying around in the future or for a spare.