<VV> RE: Vacuum adv. question

[Larry Forman]

At 10:32 PM 4/15/2004 -0400, Kevmcclain@aol.com wrote:
>Hey everyone,
>     I find myself in uncharted territory at the moment. I just bought a #177
>vacuum advance can for a 61 clip type distributor from Clark's (P.N.-
>CU7831-177) this is a used part. I tested the part with a Mity-Vac to see 
>how many
>inches of mercury it takes to actuate. Larry Forman (it's his Mity-Vac) 
>tells me
>it should begin to pull in around 9 in.Hg. And showed me how to modify it if
>it began to pull in below that. This Vac. Adv. begins pulling in at approx.
>20-22 in. Hg. and is fully in at approx. 40 in.Hg. this is for a 1961 
>80HP. If
>anyone can tell me if this is correct for the unit, and if not, what is 
>proper,
>that would be awesome. thank you in advance (no pun intended) for your help.
>-Kevin McClain

Hi Kevin,
I wonder if your old, original vac unit acts the same?  I know it did not 
leak and did not move, but forget how high I tried to get it before I 
stopped.  Regardless, if it does not open until that high, I think it is 
defective.  I don't think most Corvair engines develop that much 
vacuum.  If it is defective, I would recommend just going ahead and 
migrating to the later distributor and vacuum advance.  That way you will 
be more able to get things like distributor caps, vac advance cans, 
etc.  If you are sticking with points, then you might need to have the 
distributor rebuilt, but if you migrate to an Ignitor, you might be able to 
get by without having it rebuilt/rebushed.  You also get a gold star for 
moving up in the world!  LOL.

Larry