Crankcase ventilation.

[Righty]

You can see the hard lines to the filter in this shot, that’s why he put the little riveted ring on the carb to clear them. You can also see how the RHD setup puts the brake servo quite a bit further from the vacuum port on the manifold. It looks like the carb is already on a 1/2” spacer so swapping that out for one with a vacuum port would be an option to keep the lines short

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[nutz]

Brake servo ok on one port not pcv
Pcv fumes shouldn't be near brake cause
It can rot out the diaphragm in the servo

 

[nutz]

Oh your car is a righty didn't see that till now
The idea of having your brake on one port is so you don't lose as much vacuum to it on wide open throttle like you do under the carb
Think pcv should be there and put a 90 fitting in # 1 port

 

[nutz]

Not sure but might be able to use your breather hole and put your pcv in there then put your breather in your pcv hole

 

[BSB67]

……… could I disconnect the booster from this port and run it to the port on the manifold instead so still having constant vacuum?

Yes.

 

[Bewy]

Alrighty, [ pardon the pun ]:
- perfectly ok to run the booster hose to an intake runner. Chrys did this on 361 2 bbl intakes...& possibly others.
- that will free up the correct PCV port on the carb to use for the PCV
- if the vac adv has been connected to manifold vac, then the engine builder/tuner was smart.

 

[RustyRatRod]

You can see the hard lines to the filter in this shot, that’s why he put the little riveted ring on the carb to clear them. You can also see how the RHD setup puts the brake servo quite a bit further from the vacuum port on the manifold. It looks like the carb is already on a 1/2” spacer so swapping that out for one with a vacuum port would be an option to keep the lines short

.View attachment 1716387322

The distance has nothing to do with booster operation. The hose could be the entire length of the car and the brakes will work fine. Just remove the pipe plug from the intake runner, put a nipple in it the correct size for the hose and attach a longer hose.

 

[Righty]

Had a look at the list number on the carb it's 1850 - 4 2374. Which I think from the Holley list would be a 4160.


I'm being cautious with all this rather than just charging in because the previous owner has made more than a few modifications and fabrications throughout the car, so before I change something he's done, I'm trying to understand what the knock on from that might be.
I guess he fitted the dominator manifold and the Holley carb, and because the servo is on the right hand side he just plumbed the servo to the PCV port on the carb which was closest. And then because he had nowhere to plumb the PCV system into he just ditched it, the valve covers have 2 dead PCV valves in the grommets that have just been drilled out.
So as long as I can do a safe job of routing the servo line to the boss on the manifold I can get everything plumbed in as it should be.

On a side note the Street Dominator manifold on there is interesting, it has no EGR valve ports, the casting is blank there, apart from the firing order text which fills the space, I thought due to when they were produced that they all had the ports for EGR to meet legislation. I've got the original 2BBL, intake manifold and air cleaner in with the spares I got from him, so if ever I want to go stock it's all there!

 

[Newbomb Turk]

It’s a 600 CFM vacuum secondary carb.

Take the hose that goes to the power brake booster off the carb. Remove the pipe plug in the intake runner and hook the brake booster up there.

Hook your PCV valve to the port on the side of the carb. You want the PCV hooked to the carb, not the brake booster. The carb is calibrated for a controlled leak at that port and the PCV does that.

I almost never hook the PCV up to the manifold. It should always go to the carb. There are exceptions, especially with aftermarket carbs because some guys think a PCV is an emissions part (it is) but it is also a critical piece of the tune up picture of the carb.

 

[Righty]

Would anyone happen to know the size of the vacuum port on the intake manifold runner (Street Dominator) I think it’s 3/8 NPT, I can’t get to the car to measure right now but was hoping to order some parts for the weekend.

 

[mygasser]

in your pics it looks like it yes.
neil.

 

[RustyRatRod]

Would anyone happen to know the size of the vacuum port on the intake manifold runner (Street Dominator) I think it’s 3/8 NPT, I can’t get to the car to measure right now but was hoping to order some parts for the weekend.

It's 3/8" NPT.