[S2X01]

Anybody running (or farmiliar with) the Holley 4011 carb?

From all the research I've been doing.....it's a good carb that never caught on. Holley has ZERO support for it.

My question is.... does anyone know which vac ports go where? It's the last step in getting myself to having this old girl running.....possibly TODAY! I know the big one up front is brake booster.....but I'll just keep running that straight off the manifold. The other small 3 up front is my concern. I can post pics if needed.

Any help is awesome! Thanks in Advance!!!

[FmrStrtracer]

Posting a pic would definitely help.

How old is this carb?

Vacuum routing depends on your motor and its ignition and emissions equipment.
If you have vacuum advance on your distributor, that will use one of the smaller ports.
PCV valve should connect to the large port.
If your transmission uses a vacuum modulator valve, then thats another line used.
If you dont have any of these, you can just buy a set of vacuum plugs from the auto parts store and plug them off.

Just did a google search for your carb., Holley sold this line to Summit Racing, you can get parts from them. Its not a bad carb, people just didnt take to the different look and didnt buy many.

[S2X01]

I'll grab some pics in a few here....

I have the dist. advance ran to one of the smaller ports. Does it matter which one?

[FmrStrtracer]

Originally Posted by S2X01

I'll grab some pics in a few here....

I have the dist. advance ran to one of the smaller ports. Does it matter which one?

Need more info on type of engine and car. Some vehicles used constant vacuum for their distributor advance, some used ported(no vacuum at idle, increased vacuum with rpm)

[S2X01]

It's a 67 Riviera. 430 Big block in it. points eliminator on the dist.

[S2X01]

the one that is already ran is to my dist. i assume the smaller on the right is for my secondaries, and the larger is for PCV

[FmrStrtracer]

What transmission. T400 has a vacuum modulator. It may be connected to the manifold, behind the carb. Your distributor is hooked up correctly. Yes, your PCV goes to the large one. Plug the un-used small one, it does not operate your vacuum secondaries, that has an internal passage.

As I added above, you can get parts from Summit. Same carb, different name.

Exploded view and parts list in PDF.
http://www.holley.com/data/TechServi...ded%20View.pdf

[S2X01]

Originally Posted by FmrStrtracer

What transmission. T400 has a vacuum modulator. It may be connected to the manifold, behind the carb. Your distributor is hooked up correctly. Yes, your PCV goes to the large one. Plug the un-used small one, it does not operate your vacuum secondaries, that has an internal passage.

As I added above, you can get parts from Summit. Same carb, different name.

Exploded view and parts list in PDF.
http://www.holley.com/data/TechServi...ded%20View.pdf

Yeah...the TH400 runs to the intake already. I guess at this point i just need to find the old PCV grommet...reinstall it...hook up the new PCV valve and go!!

I may just have her started today!!!!

Thanks!

[cobalt327]

Summit might carry rebuild kits for a Holley 4011 spreadbore carb, but they don't sell a Summit brand "Holley knock-off" 4011 carb- just the 4010 squarebore knock-off.

If the engine is running, it's very easy to tell what ports do what- ported will have little/no vacuum at idle, full vacuum above idle. Manifold will have vacuum all the time.

If the engine isn't running and you are a smoker or know one you can use, with the carb off the engine connect a vacuum hose to the various small ports and blow smoke through them. A manifold vacuum port will expel smoke from an orifice that's BELOW the throttle blades, i.e. on the intake manifold side of the throttle blades. A ported vacuum port will expel smoke above the throttle plates. Same thing can be done w/carb spray if you're careful not to get a face full.

IIRC, the port right above the PCV port is a ported vacuum source.

[S2X01]

I'm carb-tarded in all honesty.

What would be the difference between ported and not?
moreso....what would be uses for a ported and uses for an unported?

apologies.....still learnin about carbs. I haven't had a carburated car since I was 16!!

[S2X01]

I'm guessing ported would be for things you want vacuum on at full throttle....ie dist advance.

others for things like brake booster, etc...that need vac all the time


I think I just answered my own question.

[cobalt327]

Originally Posted by S2X01

I'm carb-tarded in all honesty.

What would be the difference between ported and not?
moreso....what would be uses for a ported and uses for an unported?

apologies.....still learnin about carbs. I haven't had a carburated car since I was 16!!

A discussion on ported vs. manifold vacuum for the vacuum advance is HERE. Enjoy!

The modulator on the transmission (if so equipped) uses manifold vacuum, so does the power brakes, the HVAC controls in the cabin, mostly everything uses manifold vacuum except the EGR (if equipped) or the vacuum advance (if that's what works best on a particular vehicle).