PCV and power brakes on same vacuum line?

[crash]

About two months ago I switched from an Edelbrock 600 to a Holley 750 (vacuum secondaries) only real problem I had with the swap is that the Holley only has one large vacuum port on it which I used for power brakes, so I had to remove the PCV and run a breather. The problem I am having is that now all that oily gas mist smell gets into the cabin and smells horrible, so I need to figure out a way to run a PCV valve again.

There is only one hole on the intake that enters the runners to get vacuum from, problem there though is that it is under the rear float bowl of the carb and there isn't enough room to get a fitting in there. So, the way I see it now, I am stuck with one of two ways to do this... 1- remove the intake and drill / tap a hole in the runners in a spot that I can install a fitting and line for a PCV, or 2- run both the power brakes and PCV off the same vacuum line. I am unsure though as to whether or not running them on the same line would give the brake booster adequate vacuum for the brakes to function properly.

Anyone know for sure if this will work, or will it be like I think and just not be enough vacuum to the booster?

 

[drogg1]

I would say that if you were to share the one port, given that your camshaft probably is not stock, your brake booster probably would not receive adequate signal to function smoothly at least. However, I am not positive and may be worth a try still.

One possible alternative if you have clearance/means: Have you considered running a spacer? I've heard mostly good things about running some sort of spacer between the carburetor and intake effectively lengthening the intake tract. This could free up enough space to use that spot on your intake for your source of vacuum for the PCV.

 

[mebe007]

I'm having same issue. My only concern is if a spacer would for with say the performer rpm manifold under the stock hood

 

[-83MONTESS-]

If its not a stock cam why not get a vaccuum booster? My dad just did this to his 442 because his brakes sucked and this fixed (mostly) his problem :idea:

 

[pontiacgp]

you can get a carb spacer that has a vacuum port on it or you can get a spacer and drill a hole for a vacuum port

 

[crash]

Cam is a Comp Cams 280H .480 lift [email protected] duration, I have no vacuum issues at all right now, just need to run a PCV valve as well because I can't stand the smell. I have a carb spacer, but I can't use it because my air cleaner already is too close to the hood.

 

[crotchss]

I am running a Hurricane single plane intake (which is a pretty big intake) and there is no area for a thread in nipple, so both my PVC and brake booster are run off the same port with a T-fitting and I don't have any problems at all. You'll be just fine doing the same.

 

[crash]

I am running a Hurricane single plane intake (which is a pretty big intake) and there is no area for a thread in nipple, so both my PVC and brake booster are run off the same port with a T-fitting and I don't have any problems at all. You'll be just fine doing the same.

Thank you, I will try it out!

 

[Blake442]

Is there enough clearance between the port in the intake and the bowl to use a 90* elbow?

 

[mebe007]

With a performer rpm and holley no. I think Edelbrock only wants you using their carbs