Vacuum Source Q

[nvrenuf]

I don't have any vacuum ports to use a vacuum gauge for tuning. Can I tap the rake booster hose and get a true reading or will I need to cap/plug the booster side of the "T" ?

 

[Bent77]

Don’t you have a Qjet? Should be a port on the carb

But yes, you can use any port off the intake, like the brake booster

 

[nvrenuf]

@Bent77 I do currently have a qjet but my new Holley doesn’t have any ports on it. I figured that vacuum source would work I just wasn’t sure if the diaphragm in the booster might cause the gauge to behave incorrectly.

I bought a used Holley Ultra XP 850 that I’ll be putting on in a couple of weeks once I get everything for it.

 

[Bent77]

No vacuum? How will your advance work?

 

[nvrenuf]

MSD pro billet distributor, no vacuum advance.

 

[mrk5]

...... no vacuum advance.

Bold strategy, Cotton

 

[nvrenuf]

Some MSD stuff leftover from a frisky motor I used to race in mud bogs. Mechanical advance with light springs so it’s all in at 3k. It seems to work well.

 

[6872xtc]

Bold strategy, Cotton

That was my thought about the Holley.

I have the same distributor in my '70 with a BBC. It seems to work well, even though I wonder what it could gain with vacuum advance. I needed the slip collar.

 

[Bent77]

I think I’d rather have the timing controlled by the vacuum, having just switched one back from a similar set up

 

[nvrenuf]

We’ll see how it all works, I’m just wanting to wake up the motor.

For the haters.