Sick of fuel vapors

I have recently bought a 1972 El Camino with the orignal 350ci, automatic. It is mildly modified with a Eldebrock Performer intake with a Holley 600cfm vacuum secondaries and a Crane Hot cam. Also came with the original points distributor with the vacuum hose connect to the timed vacuum port. There is a original EVAP cannister with three vacuum hoses. One vacuum hose is connect to the tank vapor line. The other two vacuum hose is just laying on top of the fender skirt. I do not know where these two vacuum hoses is connected. Furthermore it does not have a PCV anywhere on this engine! I have looked at the vacuum diagrams for this car but shows the orignal 2 bbl rochester carburetor that was original equip with this car. I do not know how these two vapor hoses is connect with the Holley carb. Can you please tell me how it is set up. I am sick of these fuel vapors. Your help will be greatly appreciated. Thank You. PS. It came with the Edlebrock air cleaner with valve covers. I do not have the orignal air cleaner.

I have recently bought a 1972 El Camino with the orignal 350ci, automatic. It is mildly modified with a Eldebrock Performer intake with a Holley 600cfm vacuum secondaries and a Crane Hot cam. Also came with the original points distributor with the vacuum hose connect to the timed vacuum port. There is a original EVAP cannister with three vacuum hoses. One vacuum hose is connect to the tank vapor line. The other two vacuum hose is just laying on top of the fender skirt. I do not know where these two vacuum hoses is connected. Furthermore it does not have a PCV anywhere on this engine! I have looked at the vacuum diagrams for this car but shows the orignal 2 bbl rochester carburetor that was original equip with this car. I do not know how these two vapor hoses is connect with the Holley carb. Can you please tell me how it is set up. I am sick of these fuel vapors. Your help will be greatly appreciated. Thank You. PS. It came with the Edlebrock air cleaner with valve covers. I do not have the orignal air cleaner.

one goes to the intake manifold one to air cleaner one to gas tank....the line going to intake purges the gas from canister ,the air cleaner sucks vapor from the canister and the line from tank keeps vapors from atmosphere to be stored in charcoal canister until engine sucks vapor into air cleaner. this is like "back to the future" pcv one valve cover goes to air cleaner filtered side the other valve cover has pcv inserted into it and this then goes to intake vacuum.....I'm sure your gonna do this right!

one goes to the intake manifold one to air cleaner one to gas tank....the line going to intake purges the gas from canister ,the air cleaner sucks vapor from the canister and the line from tank keeps vapors from atmosphere to be stored in charcoal canister until engine sucks vapor into air cleaner. this is like "back to the future" pcv one valve cover goes to air cleaner filtered side the other valve cover has pcv inserted into it and this then goes to intake vacuum.....I'm sure your gonna do this right!
Are you saying I would need two PCV for each valve covers? Also, the air cleaner is made by Edlebrock with air filter. Do I punch a hole to the bottom of the air cleaner to fitting the hose from the PCV? If so, do I need a T fitting to connect the vapor hose and the PCV together? The other vapor line you have stated to the manifold. I have a fitting on top of manifold behind the carb. and this fitting with the hose is connect to the power brake booster. Do I also need a T fitting to connect this other vapor line to this fitting of the power brake booster?

Are you saying I would need two PCV for each valve covers? Also, the air cleaner is made by Edlebrock with air filter. Do I punch a hole to the bottom of the air cleaner to fitting the hose from the PCV? If so, do I need a T fitting to connect the vapor hose and the PCV together? The other vapor line you have stated to the manifold. I have a fitting on top of manifold behind the carb. and this fitting with the hose is connect to the power brake booster. Do I also need a T fitting to connect this other vapor line to this fitting of the power brake booster?


first PCV air enters usually pasenger side valve cover this supplys air to crankcase now in ancient times there was a crankcase filter attached to the non filtered side of air cleaner that went to this valve cover.the driver side valve cover has a PCV inserted in it in a rubber grommet this then went to the intake manifold directly below carb[at base of carb]facing front of car this is to be a 3/8in vac line..the vapor smaller hose should go to a small fitting at the base of carb or somewhere in this intake area...do not screw with the brake booster vacuum line . do not attach anything to it you loose vacuum you will have no braking....the passenger side valve cover could be vented by installing a breather filter mounted in it with out going to the air inlet of carb air filter this setup was used in the 60's...this was a free standing filter mounted in valve cover...

why have PCV ? this removes unburned gases from oil and other contaminates ..why base of carb between the primarys this is to mix vapor with fuel to create a better burnoff. and your injestion of fuel vapor it is obvious that this must enter the engine to be burned not vented to atmosphere as it did in the 60's , gas tank was just vented by a hose mounted at tank about 3feet long.. fill tank park car on a hot day gas would just flow into the street leaded gas ....but when your paying 25cents to the gallon so what!

first PCV air enters usually pasenger side valve cover this supplys air to crankcase now in ancient times there was a crankcase filter attached to the non filtered side of air cleaner that went to this valve cover.the driver side valve cover has a PCV inserted in it in a rubber grommet this then went to the intake manifold directly below carb[at base of carb]facing front of car this is to be a 3/8in vac line..the vapor smaller hose should go to a small fitting at the base of carb or somewhere in this intake area...do not screw with the brake booster vacuum line . do not attach anything to it you loose vacuum you will have no braking....the passenger side valve cover could be vented by installing a breather filter mounted in it with out going to the air inlet of carb air filter this setup was used in the 60's...this was a free standing filter mounted in valve cover...

why have PCV ? this removes unburned gases from oil and other contaminates ..why base of carb between the primarys this is to mix vapor with fuel to create a better burnoff. and your injestion of fuel vapor it is obvious that this must enter the engine to be burned not vented to atmosphere as it did in the 60's , gas tank was just vented by a hose mounted at tank about 3feet long.. fill tank park car on a hot day gas would just flow into the street leaded gas ....but when your paying 25cents to the gallon so what!

great information. You are very informative! As you were explaining I would now have to connect the one vapor line from the can to the base of the Holley carburetor. The other vapor line would have to be above the throttle plates where it vapors can be suck in. Can I cut the hole from the bottom of the Eldebrock air cleaner in which it have a perforated hole and to install a fitting underneath and connect the purge vacuum line to the fitting ? If I do not have any other choices for this arrangement, then I will have to buy another set of valve covers that have a PCV outlet. I guess I do need the PCV to control the gases from escaping. Without having a PCV would this cause any damage to the gaskets or seals? I really appreciate with the information you have given me sir but still not knowing how to connect the purge vacuum line above the carburetor. From your first quote you have said one vacuum line goes to the air cleaner. Please correct me if i am wrong. Thank You

if pictures can be posted of carb/intake perhaps a solution can be found to resolve these issues..... the hose from the pcv should be installed below throttle plates at base of carb... if this is not on base of your carb perhaps you can find/buy a carb base plate that will have these ports for hoses.. also by raising the carb higher above intake this allows better performance and reduces vacuum lock a condition that is caused by the gas in the carb getting too hot.........the hood is the limiting factor on how much this can be raised...

Oddly (or, not so oddly) this is a Performer and Holley 4160:

http://72.19.213.157/files/Holley4160EVAP.jpg

If your carb is similar, there should be a PCV connection. The port with the red arrow is the PCV line on this model.

The PCV and EVAP systems are completely separate, so don't get them confused. The PCV system controls crankcase vapors, the EVAP controls fuel tank vapors. Both are important, but in different ways and for different purposes.

PCV
A functioning PCV system will keep your engine much cleaner, and prolong the oil life. The PCV only requires one vacuum line, connected directly to either the carburetor or a fitting on the intake manifold (your choice). The other end of that vacuum line connects to the PCV valve, which is installed where it can draw crankcase vapors from the engine (usually a rocker cover). A second line (NOT vacuum) can be used, but doesn't have to be used. It would be a clean air supply line, or filtered atmospheric vent.

It really doesn't matter which rocker cover gets the PCV valve. The whole idea is to install a PCV valve in a part of the engine which is vented to the crankcase. The rocker cover is simply chosen because it is usually the easiest place. There must also be a means of providing fresh air into the crankcase. That's usually done with either a vented oil filler cap or vent hose (the second hose in the PCV system) connected to the air cleaner housing (the pre-perforated hole on your air cleaner base). The vent should be on the rocker cover on the opposite side of the engine from the PCV valve.

For reference, your 1972 should have looked a lot like this one:

http://72.19.213.157/files/72ChevelleEngineBay.jpg

This '72 also had a Performer/Holley installed, with a vented oil filler and PCV valve on the passenger side, extreme rear. The down side of using a vented oil filler cap is that under heavy load, blowby gasses can force oil vapor out of the vented cap and onto the engine. If the vent is connected to the air cleaner, those oil vapors are ingested into the engine and burned. This not only reduces potential pollution, but helps keep the engine bay cleaner.


EVAP
As for the EVAP canister connections, using a later model EVAP and TVS might simplify the installation. A five-port EVAP needs a purge line, tank vent line, purge control/signal line, a second purge (tank pressure control) and second signal line (usually tied to the primary purge line). That can get complicated, and require a lot of "T" fittings, short hoses, and verifying connections.

http://72.19.213.157/files/5-PortEVAP.gif

With either type, the fuel tank must have an original style filler cap with a vent/relief valve built in. Over the years, your original cap may have been replaced with a non-vented cap, so check that as well.

Oddly (or, not so oddly) this is a Performer and Holley 4160:

http://72.19.213.157/files/Holley4160EVAP.jpg

If your carb is similar, there should be a PCV connection. The port with the red arrow is the PCV line on this model.

The PCV and EVAP systems are completely separate, so don't get them confused. The PCV system controls crankcase vapors, the EVAP controls fuel tank vapors. Both are important, but in different ways and for different purposes.

PCV
A functioning PCV system will keep your engine much cleaner, and prolong the oil life. The PCV only requires one vacuum line, connected directly to either the carburetor or a fitting on the intake manifold (your choice). The other end of that vacuum line connects to the PCV valve, which is installed where it can draw crankcase vapors from the engine (usually a rocker cover). A second line (NOT vacuum) can be used, but doesn't have to be used. It would be a clean air supply line, or filtered atmospheric vent.

It really doesn't matter which rocker cover gets the PCV valve. The whole idea is to install a PCV valve in a part of the engine which is vented to the crankcase. The rocker cover is simply chosen because it is usually the easiest place. There must also be a means of providing fresh air into the crankcase. That's usually done with either a vented oil filler cap or vent hose (the second hose in the PCV system) connected to the air cleaner housing (the pre-perforated hole on your air cleaner base). The vent should be on the rocker cover on the opposite side of the engine from the PCV valve.

For reference, your 1972 should have looked a lot like this one:

http://72.19.213.157/files/72ChevelleEngineBay.jpg

This '72 also had a Performer/Holley installed, with a vented oil filler and PCV valve on the passenger side, extreme rear. The down side of using a vented oil filler cap is that under heavy load, blowby gasses can force oil vapor out of the vented cap and onto the engine. If the vent is connected to the air cleaner, those oil vapors are ingested into the engine and burned. This not only reduces potential pollution, but helps keep the engine bay cleaner.


EVAP
As for the EVAP canister connections, using a later model EVAP and TVS might simplify the installation. A five-port EVAP needs a purge line, tank vent line, purge control/signal line, a second purge (tank pressure control) and second signal line (usually tied to the primary purge line). That can get complicated, and require a lot of "T" fittings, short hoses, and verifying connections.

http://72.19.213.157/files/5-PortEVAP.gif

With either type, the fuel tank must have an original style filler cap with a vent/relief valve built in. Over the years, your original cap may have been replaced with a non-vented cap, so check that as well. Thank You for the information and the diagrams. I have recently purchased a new set of valve covers with two vented oil caps with the PCV vent outlet. I want to eliminate the possibility of removing the EVAP canister. I am assuming that this can be done. Is there a way to block out the fumes? I have seen many muscle cars with performace engines with out the use of this emission filtered vent. How is this done?

For reference, your 1972 should have looked a lot like this one: I may have seen something similar, just with out A/C and a different color. :p

I have my PCV hooked up to my carb. Its an Eldelbrock carb though. I don't have a canister, my tank cap is vented. I don't smell any fuel vapors though. I guess if it was hot outside here all the time I would...