PDA

View Full Version : G63B Intake Manifold with Weber Swap; Which Vacuum Ports can be Plugged?



jasantor
09-25-2023, 02:40 PM
Hello everyone! I hope you guys don’t get too mad but I have an ‘85 Colt Vista which has the G63B in it. I’ve been relying on you guys in the D50 forums to guide me along the restoration journey since Colt Vista info is hard to come by. Anyway, I decided to take off the intake manifold for the Weber swap I’m doing. My car has the California emissions package which makes the vacuum lines look like spaghetti. I have some pictures of the manifold if anyone would be so kind as to tell me what needs to be plugged and what needs to be utilized, I would much appreciate it. Also, I have the dual vacuum advance distributor if that helps at all. Thanks for all of the help!

https://imgur.com/a/ha04Ojf

(I couldn’t figure out how to upload the pictures from my phone, sorry for the Imgur link!)

Fingers
09-26-2023, 04:51 PM
Do you have A/C on this? On my MM there is a single-port vacuum switch that is connected to the A/C wiring. My guess is so that the compressor clutch isn't locked during start-up. So you'll probably need that one, the 2 that go to the distributor, and everything else can be plugged. Unless you have to pass emissions tests in Michigan...

Someone with more complete knowledge may correct me.

SubGothius
09-26-2023, 05:38 PM
Generally with a Weber swap, if you don't have emissions testing/inspections to worry about, the only remaining vac connections would be to the distributor vac advance, the brake booster, and the PCV. Everything else can be capped off.

I'm not sure how vac connections to a dual-barb advance capsule should be routed, so will let others here chime in on that.

The brake booster would be connected to a large barb on the intake manifold that's open to one of the cylinder intake ports, looks like that would be the large vertical barb closest to your #4 cylinder port.

The PCV barb on your valve cover would be connected to that bent port on your manifold just under the carb facing the engine between #2 and 3 cylinders.

That "tree" of barbs in the intake manifold just below the carb on the other side can be removed and replaced with a BSPT 1/8"-28 tpi plug, or just cap two of those barbs with a short U-bend of vac hose and plug the other one with a cap.

Looks like you've also got a coolant barb adjacent to your thermostat housing, so that should be capped off -- either remove that barb if you can and replace with a threaded plug (which will likely need to have BSPT threading, prolly 1/4"-19 tpi), or cap it with a short length of hose plugged with a bolt and hose-clamped at both ends.