Vacuum

[steve from staten island]

At idle my vacuum gauge holds steady at 16 1/2 is that ok?. At base of carb there are two vacuum ports one is capped and the other is for PVC, thats were I'm taking readings. Thanks

 

[WileE]

Good & plenty.

 

[oldbee]

16+ sounds fine to me. Course next question should be what kinda cam? Mine doesn’t have p/s or p/b, so I don’t hardly ever need a vacuum gauge. Jeff

 

[hunt2elk]

Must be a fairly stock cam?

 

[steve from staten island]

Yes stock cam.....So my next stupid question is how does the cam affect timing? Thanks for the education, much appreciated

 

[beanhead]

The fact that vacuum reading holds steady is a very good thing too

 

[beanhead]

Yes stock cam.....So my next stupid question is how does the cam affect timing? Thanks for the education, much appreciated

Cams with more duration like more timing generally, due to the intake valve closing later than a stock cam

 

[snakeoil24]

You have a healthy sucking motor their Steve

 

[Fran Blacker]

Steve read the first post I learned a lot from it, it's a long read but worth it.

http://www.forbbodiesonly.com/mopar...nt-vacuum-source-again.145207/#post-910868526

 

[steve from staten island]

You have a healthy sucking motor their Steve

We'll a healthy sucking 50 something year old divorcee might be interesting , but speaking of health (mine if the wife found out) i might be better off with the motor. LOL

 

[Ranger16]

Yes stock cam.....So my next stupid question is how does the cam affect timing? Thanks for the education, much appreciated

I think overlap (the period where both valves are open at the same time) has a great effect on vacuum (more overlap = less vacuum). The "hotter" the cam, the longer the duration, the greater the overlap, the lower the vacuum.