M1 Intake Manifold SBM
If I was out in my shop of horrors and I wanted to run a PCV and had to have vacuum for a brake booster I would either:
1) drill the back wall of the intake plenum oh about an inch or so (probably less) in the flat just below the carb flange and (preferably) thread it for an NPT fitting and install a 3/8 NPT barb. Hook the brake booster to that. Use the carb port for the PCV.
Or
2) Carefully drill the baseplate in the spot it would be at as on a vacuum secondary carb and install a 3/8” nipple.
3) research running a tee off the back port to hook both to. I’ve read of people on other forums doing it with no problems at all, and have read of others saying not to do that.
4) do a PCV delete
Me, I’d do number 1. If you ever passed the intake on the next guy could use it the same way. Or just thread an NPT plug in there.
Lots of older intakes have a threaded hole for a barb in that location, some on an intake runner.
Here’s an older Weiand single plane example, and where I’d drill and tap.
That’s what I thought.
If I was out in my shop of horrors and I wanted to run a PCV and had to have vacuum for a brake booster I would either:
1) drill the back wall of the intake plenum oh about an inch or so (probably less) in the flat just below the carb flange and (preferably) thread it for an NPT fitting and install a 3/8 NPT barb. Hook the brake booster to that. Use the carb port for the PCV.
Or
2) Carefully drill the baseplate in the spot it would be at as on a vacuum secondary carb and install a 3/8” nipple.
3) research running a tee off the back port to hook both to. I’ve read of people on other forums doing it with no problems at all, and have read of others saying not to do that.
4) do a PCV delete
Me, I’d do number 1. If you ever passed the intake on the next guy could use it the same way. Or just thread an NPT plug in there.
Lots of older intakes have a threaded hole for a barb in that location, some on an intake runner.
Here’s an older Weiand single plane example, and where I’d drill and tap.
