I wanted to know if there are any pros or cons to tapping the manifold and putting several fittings directly into it instead of using a vacuum block? A vacuum block is just one more thing to buy and clutter the engine bay. If you tap the manifold you can put the fittings on the underside to help clean up the engine bay. Has anyone done this? What are your thoughts? Thanks in advanced.

 

aside from air flow disruption and if you encounter a leak..it's hard to fix on a manifold, I don't see any problems. Make sure if you do that you take the IM off can clean in thoroughly because you don't want any metal shavings in the manifold

 

I have the engine out for a rebuild, so I figured it would be easy to do right now. Previously I used some T fittings and wanted to change to a cleaner setup. Bump for more info.

 

Definatly tap the manifold
Since your motor is out, you can easily remove it and not have to worry about shavings.
A decent drill bit, a tap, some teflon paste, and you'll have zero problems.

I picked up one of those AEBS manifolds for my project car, and i was pretty happy
with the fact that it had about a hundred vacuum ports on the back of it

 

Bump. Anyone else?

 

I tapped my LS manifold and I liked it. I now am going to run a vacuum block with my B16 set up. I just didn't want to tap my B16 manifold. But they are both good options.

 

theres only two things tapped off my manifold, boost guage and bov, vaccum manifold is not needed

 

tapping the manifold would be better, but a vacuum box works pretty darn well. if you have the motor apart and the Intake Manifold off, i would say tap it.

 

Well it looks like I am going to tap my manifold!!

 

I tap the IM on every build that I can. It looks WAY better and works perfectly.

Heres a vw i did.

 

Definately tap the manifold!

I am going to tap mine when I pull it out for a rebuild for sure.

It's just soo much cleaner when you have all the ports on the back of the IM rather than an extra vacuum manifold cluttering up the firewall...

I think you would get the purest readings this way too... not that you don't get good readings from a vacuum mani, but if all the ports are right there on the IM, you would think that they would all have a super clean source.

 

I went with a vacum manifold..so when i pull the motor/head/intake manifold off, I just got to undo the 1 big line that feeds it.

Chris

 

Both ways will work. Neither one is going to be better or worse. If you tap a big enough line for your vacuum manifold source you'll see no difference in how it makes your accessories react compared to directly tapping the manifold.
Like somebody already mentioned, getting a vacuum manifold is another thing you have to mount somewhere. I personally have a golden eagle manifold that I love. I was thinking about tapping the intake manifold but then the whole "space/shavings/pain in the ***" thing came to mind and I went with the Golden Eagle mani instead.
In your case though, you have the motor out, so those 3 factors I mentioned above don't come into play. I'd say in your case go ahead and tap the manifold. If you motor was in the car however I'd say go with a vacuum manifold.

 

I found taping the intake was better more repsonsive i found

 

when you tap the mani, its easier and usually cleaner to run "dedicated" hard lines or braided lines to the fpr, bov, wg, and misc solenoids. just figure out what size line(s) you need and the right size tap/drill combo and go to town