Hey Guys,

I have a Carburetor question. I have the Holley Carb pictured below.
I am unsure on where to connect the PCV hose to it.

The instruction manual, located here:

http:\\Kens71.com\Docs\HollyCarb.pdf

On page 7, section 7 just says to: “Connect the PCV hose to the PCV fitting in the carburetor.”

The problem that I have is that nowhere in the instructions does it show or list a port to plug into.

It shows 3 ports:

A. The full manifold vacuum source in the front of the throttle body provides vacuum for proper operation of the air cleaner, the pump diverter valve (if equipped), AC/Cruise, and/or the temperature sensing valve. If vacuum for more than one component is needed, use small plastic vacuum “T”s (available at most automotive stores).

B. The timed spark fitting in the choke side of the primary metering block provides vacuum for the operation of the distributor vacuum advance. Connect the hose to the distributor, spark delay valve, and/or temperature sensing valve as originally connected. Again use “T”s as necessary. If any questions arise about the hose connections, consult the proper service manual.

C. Connect the power brake hose to the fitting as shown in Figure 7.























Suggestions? Because I just don’t know.

Also, do I need to close/seal up the two fuel inlet fittings that are not being used?

Thanks
KO

 

The larger port at the base of the carb [on back side] would appear to be the best location for the PCV valve connection. And since that would have fuel vapors, etc. going into it, I wouldn't think that anything else should be attached there. I'm not quite sure [from your description] if the port on the right side of the forward body is ported or manifold vacuum, but you should be able to tell when you start the engine...by seeing if vacuum is present [or not] at idle. I suspect that this port is intended for use as your distributor vacuum control port. The small port on the right-front, at the base, is probably manifold vacuum; again, you can determine that when you have the engine idling. This port could be used for any system operation 'feed' line. Now, you do have a manifold plug just behind the carb; that would be an excellent postition for a multi-port fitting that would supply power brakes, headlights, wiper door (if you have one) and any other accessory feed needs. You may have to search for a "gang" fitting that will fit in that limited space...or you may have to make on by brazing some tubing pieces to a shortened pipe nipple. Either way, you need to make that happen to have adequate vacuum supply for your car.

I believe the 'key' to resolving all of this is getting the engine to fire, warm up, and idle so that you can isolate the 'manifold' fitting(s) vs. the 'ported' fitting(s). If it were my engine, the order of events would be: get it started and idling smoothly (at least, prior to final tuning), determine which ports are which, connect dist. vacuum line to the most appropriate fitting [for your engine's needs], adjust timing to maximize engine manifold vacuum, set idle adjustment, and set idle speed. After the engine gets cold again, you can set choke adjustments, start it up, and set fast-idle setting.

Your engine really looks great! It would be fun to work at setting it up.

 

Thanks for the detailed update.

The larger rear port is supposed to be for the power brake booster, however, since I have the hydroboost system, I will not need to use that port and can use it for the PCV connection.

And since my distributor doesn’t have a vacuum advance (another issue), that port will just get capped off. I plan on getting the electric choke kit to add to the carb. Once done, I can go about figuring out the detailed steps that I need to do to get it started. I have not had much experience with engines and don’t know how to go about starting it up without everything being back together. I am pretty good at taking things apart and putting them back together, however, I do not have the expertise needed to tune the car myself.

 

Believe me, if you can build an engine, you can TUNE an engine. You just need a bit of knowledge on "how" to do it. And, there are 'basic' tune-ups and 'thorough' tune-ups. I'd suggest that you learn the basics and leave the experts to do the 'thorough' stuff. If you have an H.E.I. or electronic ignition unit, you won't need a dwell meter; otherwise you need a timing light (with dial-back feature, unless you have a fully-degreed harmonic balancer) and a vacuum gauge. With those...and info you can get from folks on this Forum...you should have no problem doing a basic tune on your engine.

 

I wanted to put an electric choke on my holley, but air cleaner clearance was a problem. I just have the mechanical choke locked open. It starts just fine when it's cold. I don't have the other two fuel line fittings plugged and they don't leak. Also, hook the pcv to the fitting on the back of the carb.

 

The large rear port (3/8") is for the pcv and nothing else ideally goes to it. If you look at the bottom of the carb you will see this port with passages going to both sides in case it is used on a divided intake plenum so all cylinders get an even distribution of a potentially fouling mixture. If using PB, you can get the vacumn from just a single runner on the intake if necessary for that or from a tee as previously suggested.

 

Thanks for the info.

Does it matter if the PCV is on the Driver's side or passenger's side?



KO