vacuum advance question
Standard VC189 is adjustable and has 22* at the crank. Fits OEM electronic dist.
https://www.summitracing.com/parts/smp-vc189
Every can I've had with the hex on the end was adjustable.
Adjusting only changes the amount of vacuum (rate) the advance starts. CCW raises inches of vac to move and CW lowers inch of vac to move. Linkage has a number stamped on it and this would be the number of degrees the can has in distributor degrees. The VC189 is marked 11R and gives you 22 at the crank.
To limit the max advance you can mod your distributor by adding a 4-40 machine screw to limit max advance where you want it. See picture.
Someone else may chime in with a part # for an 8.5* can which would give you 17* at the crank. They used to make them but I don't have the part #.
Standard VC189 is adjustable and has 22* at the crank. Fits OEM electronic dist.
https://www.summitracing.com/parts/smp-vc189
Every can I've had with the hex on the end was adjustable.
Adjusting only changes the amount of vacuum (rate) the advance starts. CCW raises inches of vac to move and CW lowers inch of vac to move. Linkage has a number stamped on it and this would be the number of degrees the can has in distributor degrees. The VC189 is marked 11R and gives you 22 at the crank.
To limit the max advance you can mod your distributor by adding a 4-40 machine screw to limit max advance where you want it. See picture.
Someone else may chime in with a part # for an 8.5* can which would give you 17* at the crank. They used to make them but I don't have the part #.